Optics assembly for high power laser tools

Abstract

There is provided a high power laser rotational optical assembly for use with, or in high power laser tools for performing high power laser operations. In particular, the optical assembly finds applications in performing high power laser operations on, and in, remote and difficult to access locations. The optical assembly has rotational seals and bearing configurations to avoid contamination of the laser beam path and optics.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present inventions relate to optics assemblies for use with high power laser units, systems and high power laser tools, such as for example drilling, decommissioning, plugging and abandonment, perforating, flow assurance, workover and completion units.

As used herein, unless specified otherwise “high power laser energy” means a laser beam having at least about 1 kW (kilowatt) of power. As used herein, unless specified otherwise “great distances” means at least about 500 m (meter). As used herein the term “substantial loss of power,” “substantial power loss” and similar such phrases, mean a loss of power of more than about 3.0 dB/km (decibel/kilometer) for a selected wavelength. As used herein the term “substantial power transmission” means at least about 50% transmittance.

SUMMARY

In the use of high power laser tools, and in particular high power laser tools for applications and processes in remote locations, there is a need for high power optics assemblies. In particular, there is a need for such assemblies that can transmit, shape, focus, direct, and combinations thereof, high power laser energy through and adjacent to areas of rotational transition zones with in such tools. Further, and in greater particularity, there is a need for such assemblies to address vibration, temperature, contaminant, particulate and other conditions that arise from the use of high power laser energy, the tool itself, and the environment in which the tool will be used, such as for example, drilling, decommissioning, perforating, plugging and abandonment, flow assurance, workover and completion activities in the oil, natural gas and geothermal industries, as well as, activities in other industries such as the nuclear industry, the chemical industry, the subsea exploration, salvage and construction industry, the pipeline industry, and the military. Further, these tools may be used when the high power laser energy is transmitted over great distances to small and/or difficult to access locations, positions or environments for activities such as monitoring, cleaning, controlling, assembling, drilling, machining, welding and cutting. The present inventions, among other things, solve these and other needs by providing the articles of manufacture, devices and processes taught herein.

There being provided a high power laser optics assembly having: a first section and a second section; the first section having a first opening for receiving a high power laser source for providing a high power laser beam; the second section having an opening for transmitting the high power laser beam; the first opening and the second opening being in optical communication and defining an optical channel; and, a means for sealingly placing the first opening and the second opening in rotational association.

Furthermore, there are provided assemblies and packages that may also include: the assembly being capable of maintaining optical alignment, as measured by tip/tilt to less than about 0.0066 radians; the optical alignment being maintained over temperature ranges from about −100° C. to about 200° C.; the optical alignment being maintained over forces of about 100 g's; the optical alignment being maintained over forces of about 200 g's; the assembly being capable of maintaining optical alignment, as measured by tip/tilt to less than about 0.004 radians; the assembly being capable of maintaining optical alignment, as measured by tip/tilt to less than 0.018 radians; the assembly being capable of maintaining optical alignment, as measured by tip/tilt to less than 0.001 radians; the assembly being capable of maintaining optical alignment, as measured by tip/tilt to less than 0.0005 radians; the optical alignment being maintained in the presence of transmitting at least about a 5 kW laser beam between the first and second openings; the optical alignment being maintained in the presence of transmitting at least about a 10 kW laser beam between the first and second openings; the optical alignment being maintained in the presence of transmitting at least about a 50 kW laser beam between the first and second openings; the optical channel extends through the rotational sealing means, and the rotational sealing means has a bearing assembly and a rotary seal; the rotational sealing means has two bearing assemblies; the rotational sealing means has three bearing assemblies; a means for passive cooling; a means for managing back reflections; a first section and a second section and the member second section has a stepped optical channel for managing back reflections; the optics package being associated with a passive cooling means; the assembly being capable of maintaining optical alignment, as measured by defocus to less than about 0.05 mm over basic operating parameters; the assembly being capable of maintaining optical alignment, as measured by decentering to less than about 1.6 mm over basic operating parameters; the assembly being capable of maintaining optical alignment, as measured by decentering to less than about 1 mm over basic operating parameters; the assembly being capable of maintaining optical alignment, as measured by tip/tilt to less than about 0.004 radians over basic operating parameters; the assembly being capable of maintaining optical alignment, as measured by tip/tilt to less than about 0.001 radians over basic operating parameters; and the assembly being capable of maintaining optical alignment, as measured by defocus to less than about 0.05 mm over basic operating parameters.

Moreover, there is provided a high power rotating optics assembly for use with a high power laser device, the optics assembly having: an optics package including a first end, a second end, an optic and a window; a housing including a first end and a second end and a first side and a second, thus the housing second end being fixedly associated with the optics package first end; thus the housing and the optics package define a first section of the optics assembly; a member defining an optical channel, the member having a side removed from the optical channel; the member side having two bearing assemblies, the bearing assemblies being rotationally associated with the housing first side; a rotary seal in sealing engagement with the member and the housing; and, the member having an opening in optical association with the optical channel for receiving a high power laser source, thus the member and opening define a second section of the optics assembly; thus the first and second sections of the optics assembly are rotationally associated so that a laser beam may be transmitted from the first opening through the optical channel to the optics package and exit the optics package while the first section or second section being rotating relative to the other.

Yet still further, there is provided a high power rotating optics assembly for use with a high power laser device, the optics assembly having: an optics package including an optic; a housing having an opening in optical association with the optics package, the housing defining a first section of the optics assembly; a member defining an optical channel, the member having a side removed from the optical channel; thus the member being fixedly associated with the optics package; thus the member and the optics package define a second section of the optics assembly; a first bearing assembly and a second bearing assembly, having a bearing materials, the first and second bearing assemblies rotationally and axially associating the housing and the member; a rotary seal means in sealing engagement with the member and the housing, thus the first and the second bearing assemblies are isolated from the optical channel and the optics package; and, the member having an opening in optical association with the optical channel for receiving a high power laser source; thus the first and second sections of the optics assembly are rotationally associated so that so that the optics package and the optical channel are maintained substantially free from bearing material during rotation.

Still additionally, there are provided optics assemblies and packages that may also include: an opening for receiving the high power laser source, defines a receptacle for receiving a plurality of high power laser beams having a combined power of at least about 50 kW.

Further still, there is provided a high power rotating optics assembly for use with a high power laser device, the optics assembly having: an optics package including an optic; a first housing having an opening in optical association with the optics package, the first housing defining a first section of the optics assembly; a second housing defining an optical channel, the second housing having a surface removed from the optical channel; thus the second housing has the optics package; thus the housing including the optics package defines a second section of the optics assembly; a first bearing assembly and a second bearing assembly, the first and second bearing assemblies rotationally and axially associating the first housing and the second housing; and, a rotary seal means in sealing engagement with the first housing and the second housing; and, the second housing having an opening in optical association with the optical channel for receiving a high power laser source; thus the optical channel and the optics package are isolated from an environment exterior to the first housing or the second housing, during rotation and transmission of a laser beam, thus the optics package and the optical channel are maintained substantially free from contamination.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an angled perspective view of an embodiment of an optical assembly in accordance with the present invention.

FIG. 1B is a side perspective view of the embodiment of FIG. 1A.

FIG. 1C is a side cross-sectional view of the embodiment of FIG. 1A.

FIG. 2 is an exploded view of an embodiment of an optical assembly in accordance with the present invention.

FIG. 2A show a detailed end view of the embodiment of FIG. 2 in accordance with the present invention.

FIG. 2B is a side cross-sectional view taken along line B-B of FIG. 2A of the embodiment of FIG. 2.

FIGS. 2C and 2D show details cross-sectional views of FIG. 2B areas C and D, respectively, of the embodiment of FIG. 2.

FIG. 3 is an exploded view of an embodiment of an optics package in accordance with the present invention.

FIG. 4A is an angled perspective view of an embodiment of a modular optics assembly in accordance with the present invention.

FIG. 4B is a side view of the embodiment of FIG. 4A.

FIG. 4C is a cross-sectional side view of the embodiment of FIG. 4.

FIG. 5A is a schematic of an embodiment of an anti-back reflection step configuration in accordance with the present invention.

FIG. 5B is a schematic of an embodiment of an anti-back reflection step configuration in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present inventions relate to optical assemblies for delivering and utilization of high power laser energy. In particular, the present inventions relate to optical assemblies for use in tools for performing activities such as drilling, working over, completing, cleaning, milling, perforating, monitoring, analyzing, cutting, removing, welding and assembling.

The high power laser optics assemblies of the present invention, in general, address and manage shock, thermal, cleanliness, and laser beam delivery parameters for a high power laser tool, as well as, other environmental and operational conditions. Further, these factors may be addressed and managed by the present high power laser optics assemblies in the area of rotational transition zones of a tool. A rotational transition zone is any area, section, or part of a tool, where rotating components merge with, are jointed to, overlap with, or are otherwise mechanically associated with non-rotating components, components rotating in a different direction, components rotating at a different speed, and combinations and variations of these.

Turning to FIGS. 1A, 1B and 1C there are shown a perspective view, a side view and a cross-sectional view of an embodiment of an optics assembly 100. The optics assembly 100 has three sections, 110, 130, 150. The sections are combined in a manner that seals the interior components from the exterior environment, such that environmental contaminates are kept out of, or substantially kept out of, the interior of the assembly 100. The assembly is made from materials, such as metal, ceramic, and for example aluminum, stainless steel, steel, brass, titanium, and copper, which are capable of radiating or otherwise transmitting heat that may be built up by the transmission of a high power laser beam through the assembly. Preferably, each section of the assembly has cooling fins, e.g., 111, 191, 151.

Greater or fewer sections for the optics assemblies are contemplated. Although the sections are shown as individual components that are affixed together by a securement means, such as for example a bolt, a screw, a press fit, or a threaded connection, they may also be integral, made from a single piece of material, fused, or welded together, and also include sub-section(s) that are integral or separate or combinations and variations of the foregoing. Greater or fewer cooling fins are contemplated. Thus, there may be two, three or more, five or more, ten or more, and twelve or more fins or cooling members. Additional fins may be needed, or used for, example where there are high heat loads, or where the diameter of the assembly is larger. Active cooling means, such as a water-cooling system, may be utilized, however, and in particular, for remote applications, passive cooling, as shown in the embodiment of FIGS. 1A to 1C, and the other embodiments of the figures in this specification, is preferred. As used herein passive cooling is any means of cooling that does not employ or use an additional system or equipment to cool the assembly; but instead relies on only the operating environment and operating conditions, e.g., flow of a fluid used to remove cuttings or waste form a work site, of the tool to manage and cool the heat associated with the optics assemblies.

In the embodiment of FIGS. 1A to 1C, sections 110 and 130 are fixed, forming section 102, and do not rotate with respect to each other. Section 150 is rotationally connected to section 102, and thus, section 102 can rotate with respect to section 150.

Although two sections are shown rotationally associated in the embodiment of FIGS. 1A to 1C, greater or fewer sections are contemplated. Each section may further have sub-sections or components, which may also be rotationally associated, fixed and combinations thereof.

The optics assembly 100 has two optical communication openings, 103 and 104. High power laser energy is transmitted into and out of these openings. In general, either opening may be configured to either receive or transmit the high power laser energy. The openings may be configured to hold or receive a high power optical fiber or cable, to hold or receive an optical coupler, to receive or transmit a high power laser beam that may be collimated (either as received, as transmitted or both), that may be focused (either as received, as transmitted or both), that may be Gaussian (either as received, as transmitted or both), that may have a predetermined power distribution or beam profile (either as received, as transmitted or both), that may be shaped (either as received, as transmitted or both), that may be divergent (either as received, as transmitted or both), that has more than about 1 kW of power, that has more than about 2 kW of power, that has more than about 5 kW of power, that has more than about 10 kW of power, that has more than about 15 kW of power, that has more than about 20 kW of power, that has more than about 40 kW of power, that is a single beam, that is made up of multiple beams, a plurality of separate beams, and combinations and variations of these and other laser beam qualities and parameters.

In the embodiment of FIGS. 1A to 1C, opening 104 is configured to receive an optical coupler connected to the end of a high power optical fiber, and is the receiving opening for the laser beam. Opening 103 is configured to transmit the laser beam. Opening 103 has a window 112 and optics 113, for collimating, shaping and focusing the laser beam.

To accommodate the different rotational movements of section 102 and 150, sealing members and bearings members are utilized. These members may be any type of such devices known to the art, they may be separate devices, they may be combined, there may be a single device or there may be several devices distributed or located at certain positions in the assembly. Provided however, that they are configured to meet the vibration, shock, pressure, speed, alignment tolerance, temperature and other operating parameters and conditions that the optics assembly will encounter, or need to meet, during its intended use, e.g., during the intended or specified use for the tool or device in which the optics assembly is employed.

As shown in FIG. 1C, there are three bearing assemblies, 131, 132, 133, and a retaining ring 136 that provides a preload to bearing 133, through pre-load ring 134, which also retains O-ring 135. For example the bearings 131, 132 may be angular contact ball bearings and bearing 133 may be an angular contact ball bearing. Additionally, to facilitate sealing, e.g., containment of the bearings and bearing material thus manage and reduce contamination and potential contamination from the bearings, bearing material, a multiply-alkylated cyclopentane based grease, such as for example, Rheolube 2000 from Nye Lubricants, is applied to the bearings and preferably all surfaces that contact the bearing races. This material may also be applied to the rotary seals. Additionally, this grease may be applied to the surfaces contacting the pre-load ring 134. The o-ring 135 may be made from an elastomeric type ring, that is durable, does not sluff, and is high temperature stable (preferably up to about 300 F or greater) for example Viton. The pre-load ring 134 may be made from any metal that is durable, and has sufficient stiffness to apply the required pre-load, for example stainless steel. The bearings may be tapered roller bearings, cylindrical roller bearings, radial ball bearings, four point contact ball bearings, thrust ball bearings, journal bearings and magnetic bearings, by way of example. All three bearings, or all such bearings in a particular optical assembly may be the same type of bearing, or they may be different types. Further, and as shown in greater detail in the embodiment of FIGS. 2C and 2D, a barrier film, may be used on the surfaces adjacent to the bearings. The barrier film should provide a specific barrier to material, debris or other substances in the fluid flow. For example, if a positive displacement motor (“PDM”) is used with air flow, which requires a lubricant such as oil to be in the air flow, the barrier film should be selected to provide a barrier to oil migration. An example of such an oil barrier film would be Nyebar L from Nye Lubricants, which functions by providing a thin layer of material that has a very low surface energy and thus prevents oils and grease from migrating across it.

Turning again to FIGS. 1A to 1C, to keep the optics and the beam path within the assembly 100 free from debris and contamination, or substantially free from debris and contamination such that the high power laser performance of the system is not significantly adversely affected, the members must seal the beam path sufficiently to prevent, substantially restrict, and preferably restrict external contaminates from entering into the interior of the assembly, e.g., getting into or onto the beam path or optics. Additionally, these members should not be a source of contamination themselves. Thus, these members and any lubricants that are used in conjunction with them should not produce, introduce or cause to be introduced, contamination into the interior of the assembly, e.g., getting into or onto the beam path or optics. Maintaining the cleanliness of the beam path and optics is important, as even a small amount of contamination may cause the assembly to fail or degrade the quality of the laser beam, by for example being affixed to an inner surface and heated by the high power laser beam, causing the assembly to fail.

Preferably, by way of example, the optics assembly of the embodiment of FIGS. 1A-C, may be used for example in a laser bottom hole assembly, such as the laser bottom hole assembly of U.S. patent application Ser. No. 12/896,021, Ser. No. 61/446,042, co-filed U.S. patent application Ser. No. 13/403, 287, now issued as U.S. Pat. No. 9,074,422, filed contemporaneously herewith, and US patent application publication number 2010/0044104, the entire disclosures of each of which are incorporated herein by reference.

The configurations of the optics assemblies of the present inventions provide the ability to, and thus, may meet, and can be further designed and constructed to exceed, the following criteria, operating conditions and performance criteria:

• • temperature up to 120° C. and may be up to 250° C. and higher;
  • pressure up to 300 psi, and may be up to 600 psi, with a Sapphire window of about 5 mm thickness; and higher pressures with thicker and/or stronger window configurations;
  • g-forces up to 200 g's and greater g-forces up to 500 g's and higher, if more robust components and designs are utilized;
  • capable of handling laser powers of greater than about 5 kW, greater than about 10 kW, greater than about 20 kW, and with more robust components, added thermal capacity, and enhanced design features, such as the anti-back reflection steps of FIG. 5, greater than about 40 kW, greater than about 60 kW and greater;
  • rotational speeds from about 0 RPM (revolutions per minute), less than 1 RPM up to about 300 RPM and greater, up to about 500 RPM and greater, up to about 1000 RPM and greater, and with a more robust design and components greater than 2500 RPM;
  • low temperatures of about down to about −20° C., about −40° C. and as low as about −143° C.;
  • and, can maintain optical alignment, as measured by tip/tilt, (e.g., pointing error) throughout some, and preferably all of the foregoing conditions (herein referred to as “basic operating parameters”), for example, of less than about 0.018 radians, of less than about 0.0066 radians, or less then about 0.004 and most preferably of less than about 0.001 radians. Smaller tip/tilt values may be obtained with enhanced designs and components, such as those of the embodiment in FIG. 4, which may be as small as less than about 0.0005 radians, and less than about 0.0001 radians; and, can maintain optical alignment, as measured by decentering (e.g., concentricty) throughout some and preferably all of the foregoing conditions, for example of less than about 1.6 mm, of less than about 1 mm, or preferably less then about 0.5 mm. Smaller decentering values may be obtained with enhanced designs and components, such as those of the embodiment in FIG. 4, which may be as small as less than about 0.25 mm, 0.05 mm, and less;
  • and, can maintain optical alignment, as measured by defocus throughout some and preferably all of the foregoing conditions, for example of less than about 0.7 mm, of less than about 0.5 mm, or less; and,
  • for beam patterns that are not axially symmetric, can maintain tolerance for clocking throughout some and preferably all of the foregoing conditions, of less than about 0.03 radians, and less.

Turning again to the embodiment of FIGS. 1A to 1C there is also shown a retaining ring 136, a seal carrier 137, a flexible sealing member 152, e.g., a v-seal or lip seal, and an optics receiving tube 153 having an optical channel 154, and a locking ring 156. The retaining ring 136 also has an optical channel 138.

The retaining rings and optics receiving tube may be made from metal, such as Aluminum, Stainless Steel, or Brass or Copper. The inner surfaces of these components, along the beam tube, as well as any non-transmissive inner surface, (e.g., generally all other components except the optics) in the assembly, that directly face the high power laser beam, should be made to reflect the laser beam. Thus, these surfaces may be polished or coated with reflective materials, such as Gold, Silver, Copper, and alloys for the foregoing. However, for the purpose of heat management and to enhance heat transfer from the optics and interior to the fins, inner surfaces, e.g., 157, 158, 159, 160 that are in direct thermal contact with the fins may be made with or have a non-reflective black surface, such as black chrome, laser black, and black anodize.

The optical channels 154, 138 are in optical communication. Each channel as a series of steps, or terraces, with increasing inner diameters. Thus, for example step 140 has a larger diameter than step 141. Each step also has a flat surface, an annulus, that is normal to the axis of the beam path, e.g., 140a, 141a. These surfaces function to prevent back reflections, for example from a laser beam back reflection, e.g., back reflections, entering the optics 113, from entering the fiber and/or coupler that is located in opening 104 and from which the beam is received by the assembly 100. Thus, these surfaces, e.g., 140a, 141a, reflect back toward the optics, and away from receiving opening 104, back reflections that may be traveling toward the opening 104. The optical channels 138, 154 form a continuous optical channel having seven steps of increasing diameter, as the location in the continuous channel moves away from the opening 104. More or fewer steps, steps having larger and smaller diameters, and steps having different shapes may be employed.

Optics tube 153 and section 150 are joined through locking ring 156. In this manner optics tube 153 is fixed to and rotates with section 150. Similarly, ring 137, and 136 are fixed to and rotate with section 130 (also section 102). For a thermal gasketing effect to enhance heat transfer Indium foil is used between the surface of tube 153 and the cooling fins 151 of section 150, where they overlap. Thus, in use or as part of a high power laser tool, the assembly 100 would be located in the area of a rotational transition zone of the tool, with section 102 being associated with a first section of the tool, and section 150 being associated with second section of the tool that has a different rotation movement from the first section, e.g., the first section rotates and the second section does not.

There are further optic 180, optic 181, optic 182, and springs 183, and 184, that are in optical communication with the optical channels 154, 138 and the openings 104 and 103.

As can been seen from the FIGS. 1A to 1C and in particular in FIG. 1C there are provided other spacers, springs, washers, etc. that provide example of the assemblies that may be used in the optical assembly to hold and position the various components of the assembly.

In FIGS. 2 and 2A to 2D, there is provided illustrations of an embodiment of an optics assembly 200 having two sections, 201, 202. The assembly 200 has an opening 204 and a transmitting opening 203 that are in optical communication along a laser beam path by the optical channel formed by inner tube 205. The opening 203 is configured for attachment to optics, a coupler, or other devices that may be part of or incorporated into the laser tool in which the assembly 200 will be used.

The embodiment of FIGS. 2, 2A to 2D has a locking member 214, e.g., a nut, a wave spring 218, e.g., of stainless steel with a crest-to-crest 1.5 inch outside diameter, a cooling fin section 213, and a sleeve 212, which may be indium ribbon, 0.002×1 inch cut to length so as not to over lap when wrapped around a part. The locking member 214 threadably engages inner tube 205. Locking engagement ring 211 theadably engages cooling fin section 207, and captures rotary seal 210, e.g., flexiseal rotary seal, flanged, 1.187 shaft diameter, v-spring, retainer 209, a plurality of screws 215, which are threaded into retainer 211, and an o-ring 208, e.g., 2.5 inches by 1/16 inches. Thus, fin section 207 and engagement ring 211 rotate with respect to inner tube 205. Fin section 213 is tapper fitted and thus does not rotate with respect to inner tube 205 on sleeve 212. Bearing sections 206, 224 are positioned between inner tube 205 and fin section 207, to accommodate the rotation of fin section 207 in relation to inner tube 205, and are held in position by spring 216, e.g., a wave spring providing a preload, 47 mm, 129N stainless steel, o-ring 222, e.g., AS568-135 viton, preload ring 223, and locking ring 236. Locking ring 236 engages and is fixed to fin section 207, and engages ledge 237 of fin section 207 holding the inner tube 205 in position. Thus, fin section 207 is held in place and is rotatable around, or with respect to, inner tube 205.

Turning to FIGS. 2C and 2D there is provided a detailed view of areas C and D from FIG. 2B respectively, of a preferred embodiment of a sealing and bearing member, further showing the position of barrier films 260a, 260b, 261a, 261b, 262a, 262b. It should also be noted that FIG. 2 shows an exploded view, and that as assembled tube 205 captures and supports fin section 213 by ring 214, and thus forms section 201 of the optics assembly 200.

Turning to FIG. 3, there is shown an exploded view of an optics package that may be used with or as a part of an optics assembly. The optics package may be attached to, or be, an optical communication opening for an optics assembly. The components of the optics package include a retaining ring 301, a lens 302, a spacer 303, a window 304, a cooling fin section 305, shims 306a, 306b (which are clocking shims to maintain alignment of the associated optics), spacers 307, 308, 309, collimator lens 310, o-ring 314, retainer ring 312, prism 315, and springs 317, 316.

Turning to FIGS. 4A to 4C there is shown a perspective view, side view and cross sectional view of an embodiment of an optics assembly 400. The assembly 400 has windows, 423, 421, 422, labyrinth seals 424, 425, 426, 427, and gold plating on inner surface of cavity 492. The optics assembly 400 has two sections 450 and 402, which are rotationally associated. Section 402 is made up of an optics package 410, and an outer sleeve 430. The optics package 410, at one end forms an optical communication opening 403, which in the case of this embodiment is for transmitting the laser beam from the optical assembly (window 423 is associated with opening 403). The sleeve 430 is fixed to optics package 410 by way of, for example, bolts, e.g., 485a through piece 485. Thus, sleeve 430 and optics package 410 rotate together as a unit, or move as a unit, relative to section 450.

Section 450 forms an optical communication opening 404 and is configured to receive a connector. Section 450 forms an optics tube 450a that has a stepped configuration 450b to inhibit back reflections from reaching the connector. Section 450 has a collimating lens 452. Section 450 is affixed to inner sleeve 451 by for example bolts, e.g., 451a. Thus, section 450 and inner sleeve 451 rotate or move together as a unit. Between inner sleeve 451 and outer sleeve 430 are bearing and seal members, which in this embodiment are four bearing assemblies 480, 481, 482, 483 and a sealing and locking member 484. The sealing and locking member 484 is affixed (e.g., threads, bolts etc.) to the inner sleeve 451. In this manner, the member 484 engages bearings 483, 482 forcing them into engagement with shoulder 431 on outer sleeve 430. Thus, inner sleeve 451 is held in rotational engagement with outer sleeve 430. It being noted that the laser beam as it passes through the cavity 492 formed by the inner and outer sleeves is a collimated beam. (In other embodiments the laser beam may be focused, divergent and/or shaped)

The embodiment of FIGS. 4A-C provides for a modular type of system that allows for the removal of section 450, the optics package 410, or section 402, or the bearing assembly. In this way for example, a damaged section could be easily replaced, or alternative sections for different applications could be used. Further the windows 421, 422, 423 may be quickly and easily replaced. This embodiment also provides the ability to connect section 450 into section 451, without the need to visual observe the connection process, e.g., what may be referred to as a blind stab. In this manner a high power fiber may be attached to and secured in section 450 through opening 404. That section and the fiber may then be incorporated into a high power laser tool. Section 402 may then be put into another section or component of that tool, and when the two components of the tool are brought together, the two components of the optical assembly will also be brought together and aligned by way of the tapered edges of section 451, and 460.

There are further provided purge valves, or pressure equalization ports, e.g., 470, 471 in the inner and outer sleeves. Preferably these ports have sintered metal filters, or other devices to prevent debris from entering. The ports enable the pressure between the inner and outer members, annulus 491, and the inner cavity 492 of the inner member 451 to be equalized. In this manner a condition where a high pressure is present outside of the inner cavity 492 then inside the inner cavity, which conditions would tend to drive or force debris past the seal 484, should not exist, or should be substantially avoided. In this manner the pressure equalizing ports form a part of the bearing and sealing member.

The forgoing bearing and sealing components, as set forth in the various embodiments, are configured to protect the optics, the optics package, and the optical channel from contamination during rotation of the various components. Thus, for example, the seals and bearing assemblies are configured and positioned to prevent bearing materials, such as shavings, wear debris, stuffings or grease from entering the optical channel or otherwise contaminating any optical surface that transmits the high power laser beam. In this manner those assemblies are isolated, or substantially isolated for practical purposes from the optical channel and the optics.

Turning to FIG. 5A there is provided a schematic diagram of a step configuration of an inner optical cavity to manage and mitigate back reflections. Thus, there is shown a centerline 501 of an optical cavity 502. The direction of the laser beam (e.g., the forward propagating high power laser beam as it travels along a laser beam path toward an intended target, work piece, etc. to perform an intended laser operation) in the cavity 502 is shown by arrow 503 as it enters the cavity 502 and travels to the optic 504, e.g., lens, collimating lens, etc. There are provided a plurality of steps 505 having knife edges 506. The steps form a progressively wider optical cavity along the direction of the laser beam. Thus, the cavity 502 is widest at the optic 504. The knife edges 506 tapper outwardly, e.g., making a wider cavity, with respect to the direction of the laser beam. The steps 505 may be formed from a unitary piece or they may be individual inserts, that may be changed to meet a particular back reflection condition based upon a particular laser operation or work piece. The back reflections would travel generally in a direction opposite arrow 503.

Turning to FIG. 5B there is provided a schematic diagram of a step configuration of an inner optical cavity to manage and mitigate back reflections. Thus, there is shown a centerline 520 of an optical cavity 522. The direction of the laser beam (e.g., the forward propagating high power laser beam as it travels along a laser beam path toward an intended target, work piece, etc. to perform an intended laser operation) in the cavity 522 is shown by arrow 523, as it enters the cavity 522 and travels to the optic 521, e.g., lens, collimating lens, etc. There are provided a plurality of steps 525 having spaces 526, or separations between them. The steps 525 form a progressively wider optical cavity along the direction of the laser beam. Thus, the cavity 522 is widest at the optic 521. The steps 525 may be formed from a unitary piece or they may be individual inserts, that may be changed to meet a particular back reflection condition based upon a particular laser operation or work piece. The back reflections would travel generally in a direction opposite arrow 523.

The knife edged configured steps of FIG. 5A may be employed with the staggered or spaced steps of FIG. 5B. It further should be understood that only half of the optical cavity is shown in FIGS. 5A and 5B, and that the same step pattern would also be present on the other side of the centerline.

The laser assemblies of the present invention may be used with any high power laser tools or systems.

Examples of embodiments and teachings regarding high power optical fiber cable, fibers and the systems and components for delivering high power laser energy over great distances from the laser to a remote location for use by a tool are disclosed and taught in the following US Patent Applications and US Patent Application Publications: US 2010/0044106, US 2010/0044105, Publication No. US 2010/0044104, Publication No. US 2010/0044103, US 2010/0215326, Publication No. 2012/0020631, Ser. No. 13/210,581, Ser. No. 13/366,882, Ser. No. 61/446,042, Ser. No. 61/493,174, Ser. No. 61/514,391, and Ser. No. 61/446,312, the entire disclosures of each of which are incorporated herein by reference.

In these methods, systems and applications, the laser beam, or beams, may for example have 10 kW, 20 kW, 40 kW, 80 kW or more power; and have a wavelength in the range of from about 445 nm (nanometers) to about 2100 nm, preferably in the range of from about 800 to 1900 nm, and more preferably in the ranges of from about 1530 nm to 1600 nm, from about 1060 nm to 1080 nm, and from about 1800 nm to 1900 nm. Further, the types of laser beams and sources for providing a high power laser beam may be the devices, systems, optical fibers and beam shaping and delivery optics that are disclosed and taught in the following US Patent Applications and US Patent Application Publications: Publication No. US 2010/0044106, Publication No. US 2010/0044105, Publication No. US 2010/0044103, Publication No. US 2010/0044102, Publication No. US 2010/0215326, Publication No. 2012/0020631, Ser. No. 13/210,581, and Ser. No. 61/493,174, the entire disclosures of each of which are incorporated herein by reference. The source for providing rotational movement may be a string of drill pipe rotated by a top drive or rotary table, a down hole mud motor, a down hole turbine, a down hole electric motor, and, in particular, may be the systems and devices disclosed in the following US Patent Applications and US Patent Application Publications: Publication No. US 2010/0044106, Publication No. US 2010/0044104, Publication No. US 2010/0044103, Ser. No. 12/896,021, Ser. No. 61/446,042 and Ser. No. 13/211,729, the entire disclosures of each of which are incorporated herein by reference. The high power lasers for example may be fiber lasers or semiconductor lasers having 10 kW, 20 kW, 50 kW or more power and, which emit laser beams with wavelengths preferably in about the 1064 nm range, about the 1070 nm range, about the 1360 nm range, about the 1455 nm range, about the 1550 nm range, about the 1070 nm range, about the 1083 nm range, or about the 1900 nm range (wavelengths in the range of 1900 nm may be provided by Thulium lasers). Thus, by way of example, there is contemplated the use of four, five, or six, 20 kW lasers to provide a laser beam in a bit having a power greater than about 60 kW, greater than about 70 kW, greater than about 80 kW, greater than about 90 kW and greater than about 100 kW. One laser may also be envisioned to provide these higher laser powers.

The tools that are useful with high power laser systems, and which can incorporate or utilize the optical assemblies described herein, many generally be laser drills, laser bottom hole assemblies, laser cutters, laser cleaners, laser monitors, laser welders, laser perforators, laser PIGs, and laser delivery assemblies that may have been adapted for a special use or uses. Configurations of optical elements for collimating and focusing the laser beam can be employed with these tools to provide the desired beam properties for a particular application or tool configuration.

Such tools for example may be used for cleaning, resurfacing, removal, and clearing away of unwanted materials, e.g., build-ups, deposits, corrosion, or substances, in, on, or around a structure, e.g. the work piece, or work surface area. Such unwanted materials would include by way of example rust, corrosion, corrosion by products, degraded or old paint, degraded or old coatings, paint, coatings, waxes, hydrates, microbes, residual materials, biofilms, tars, sludges, and slimes.

Although a single optical opening is shown in the embodiments of the figures, the optical assemblies may be configured, either through a single opening or multiple openings, to handle one, two, three or more fibers, or optical connectors. They may further have one, two, three or more collimators and collimated beam paths, which paths may be overlapping. Additionally, one, two, three or more of the optical assemblies may be use in, or in conjunction with a particular laser tool or laser system for deploying a laser tool(s).

The invention may be embodied in other forms than those specifically disclosed herein without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive.

Claims

1. A high power laser optics assembly comprising: a. a first section and a second section;b. the first section having a first opening for receiving a high power laser source for providing a high power laser beam;c. the second section having a second opening for transmitting the high power laser beam;d. the first opening and the second opening being in optical communication and defining an optical channel; and,e. a means for sealingly placing the first opening and the second opening in rotational association.

2. The high power optical assembly of claim 1, wherein the assembly is capable of maintaining optical alignment, as measured by tip/tilt to less than about 0.0066 radians.

3. The high power optics assembly of claim 2, wherein the optical alignment is maintained over temperature ranges from about −100° C. to about 200° C.

4. The high power optics assembly of claim 3, wherein the optical alignment is maintained over forces of about 100 g's.

5. The high power optics assembly of claim 4, wherein the optical alignment is maintained over forces of about 200 g's.

6. The high power optics assembly of claim 2, wherein the optical alignment is maintained over forces of about 100 g's.

7. The high power optics assembly of claim 2, wherein the optical alignment is maintained in the presence of transmitting at least about a 5 kW laser beam between the first and second openings.

8. The high power optics assembly of claim 2, wherein the optical alignment is maintained in the presence of transmitting at least about a 10 kW laser beam between the first and second openings.

9. The high power optics assembly of claim 2, wherein the optical alignment is maintained in the presence of transmitting at least about a 50 kW laser beam between the first and second openings.

10. The high power optics assembly of claim 9, comprising a means for managing back reflections.

11. The high power optics assembly of claim 2, wherein the optical channel extends through the rotational sealing means, and the rotational sealing means comprises a bearing assembly and a rotary seal.

12. The high power optics assembly of claim 2, comprising a means for passive cooling.

13. The high power optics assembly of claim 2, comprising a means for managing back reflections.

14. The high power optics assembly of claim 1, wherein the assembly is capable of maintaining optical alignment, as measured by tip/tilt to less than about 0.004 radians.

15. The high power optics assembly of claim 14, wherein the optical alignment is maintained in the presence of transmitting at least about a 5 kW laser beam between the first and second openings.

16. The high power optics assembly of claim 15, wherein the optical channel extends through rotational sealing means, and the rotational sealing means comprises a bearing assembly and a rotary seal.

17. The high power optics assembly of claim 16, comprising a means for passive cooling.

18. The high power optics assembly of claim 16, comprising a means for managing back reflections.

19. The high power optics assembly of claim 14, wherein the optical alignment is maintained in the presence of transmitting at least about a 10 kW laser beam between the first and second openings.

20. The high power optics assembly of claim 14, wherein the optical alignment is maintained in the presence of transmitting at least about a 50 kW laser beam between the first and second openings.

21. The high power optics assembly of claim 14, wherein the optical channel extends through the rotational sealing means, and the rotational sealing means comprises a bearing assembly and a rotary seal.

22. The high power optics assembly of claim 21, comprising a means for passive cooling.

23. The high power optics assembly of claim 21, comprising a means for managing back reflections.

24. The high power optics assembly of claim 14, comprising a means for managing back reflections.

25. The high power optics assembly of claim 1, wherein the assembly is capable of maintaining optical alignment, as measured by tip/tilt to less than 0.018 radians.

26. The high power optics assembly of claim 25, wherein the optical alignment is maintained in the presence of transmitting at least about a 5 kW laser beam between the first and second openings.

27. The high power optics assembly of claim 25, wherein the optical channel extends through rotational sealing means, and the rotational sealing means comprises a bearing assembly and a rotary seal.

28. The high power optics assembly of claim 27, wherein the rotational sealing means comprises two bearing assemblies.

29. The high power optics assembly of claim 25, comprising a meat for managing back reflections.

30. The high power optics assembly of claim 1, wherein the assembly is capable of maintaining optical alignment, as measured by tip/tilt to less than 0.001 radians.

31. The high power optics assembly of claim 30, wherein the optical alignment is maintained in the presence of transmitting at least about a 5 kW laser beam between the first and second openings.

32. The high power optics assembly of claim 30, wherein the optical alignment is maintained in the presence of transmitting at least about a 10 kW laser beam between the first and second openings.

33. The high power optics assembly of claim 30, wherein the optical alignment is maintained in the presence of transmitting at least about a 50 kW laser beam between the first and second openings.

34. The high power optics assembly of claim 30, wherein the optical channel extends through rotational sealing means, and the rotational sealing means comprises a bearing assembly and a rotary seal.

35. The high power optics assembly of claim 30, comprising a means for managing back reflections.

36. The high power optics assembly of claim 1, wherein the assembly is capable of maintaining optical alignment, as measured by tip/tilt to less than 0.0005 radians.

37. The high power optics assembly of claim 1, wherein the optical channel extends through the rotational sealing means, and the rotational sealing means comprises a bearing assembly and a rotary seal.

38. The high power optics assembly of claim 1, wherein the rotational sealing means comprises two bearing assemblies.

39. The high power optics assembly of claim 1, wherein the rotational sealing means comprises three bearing assemblies.

40. The high power optics assembly of claim 1, comprising a means for passive cooling.

41. The high power optics assembly of claim 40, comprising a means for managing back reflections.

42. The high power optics assembly of claim 1, comprising a means for managing back reflections.

43. The high power optics assembly of claim 1, wherein the assembly is capable of maintaining optical alignment, as measured by tip/tilt to less than about 0.004 radians over basic operating parameters.

44. The high power optical assembly of claim 1, wherein the assembly is capable of maintaining optical alignment, as measured by tip/tilt to less than about 0.001 radians over basic operating parameters.

45. The high power optical assembly of claim 1, wherein the assembly is capable of maintaining optical alignment, as measured by defocus to less than about 0.05 mm over basic operating parameters.

46. The high power optical assembly of claim 1, wherein the assembly is capable of maintaining optical alignment, as measured by decentering to less than about 1.6 mm over basic operating parameters.

47. The high power optical assembly of claim 1, wherein the assembly is capable of maintaining optical alignment, as measured by decentering to less than about 1 mm over basic operating parameters.