Patent Application
20160266335
1. Field of the Invention
The present invention relates generally to media converters, and more particularly, to media converters designed to function in harsh ambient environments.
2. Description of Related Art
Media converters that commonly include optoelectronic transceivers generally include photo-detectors and lasers that convert data signals between optical and electronic transmission formats. Media converters transmit and receive digital optical signals in computers, servers, routers or switches, and are essential subassemblies in these communications systems. Media converters include numerous optical, electronic and optoelectronic components. These optoelectronic components enable media converters to transmit and receive digital or analog optical signals under electronic signal control by converting electronic signals into digital or analog optical signals for transmission over fiber optic cables and networks. Media converters also function by receiving and converting digital optical signals into electronic digital signals for use by the host computers, servers, routers or switches. Since the size of the components is very small in a media converter assembly and they are susceptible to humidity, dirt, dust and multiple other contaminants that can cause degradation, a controlled environment is mandatory for its components to be housed in order to operate efficiently and reliably.
A transmit optical subassembly or TOSA typically comprises, at least, a minimum of a solid-state laser device and a light transmission conductor along with conventional data signal electronic control circuits. These circuits control and drive a solid-state laser in order to generate light pulses under an electronic control. The receive optical subassembly or ROSA, at a minimum, is similarly constituted of a photo-detector and a light transmission conductor together with electronic circuits necessary both to convert the output of a photo-detector into usable electronic data signals and to transmit and condition the output signals of a photo-detector. The photo-detector output signals are generated by light pulses that impinge upon the detection surface of a photo-detector by an associated light transmission conductor.
Typically, optical data signal conductors are optical fibers. The digital light signals are conducted into and out of a transceiver assembly often by very small optical fibers, usually effective propagation elements in the order of 8-10 microns in diameter. Similarly, the exit or the light projection aperture of a solid-state laser is commensurately small. The photo-detector detection surface may be similarly small in high speed devices so that all of the light of the incoming digital signal impinging on the detection surface may be equally susceptible to environmental contaminants and environmental physical influences. With the diameter of the transmission core of an optical fiber being typically 8-10 microns, the placement of and quality of the pulses of light are critical. Light signals must not be attenuated or degraded by contaminants or other external hazards and physical influences on any of the optical fiber end faces, surfaces of lenses, surfaces of reflection suppressors, faces of the optoelectronic components, or in the atmospheric light path.
Very significant efforts are made to create extremely accurate alignments of the optical elements of the system. In more enhanced systems, the digitized optical signal may be passed through one or more lenses and an anti-reflection isolator, and then may be reflected off angled surfaces on the end of an optical fiber to direct, control and position the light pulses properly relative to other optical elements of the system.
Contaminants and other external hazards introduced into or allowed to enter the internal environment of a media converter module may include dust particles, water, water vapor or condensate, dust, fumes, smoke, and even varying ambient pressure changes. Such contaminants and pressure changes may reduce or alter the light signal transmission strength sufficiently to render the media converter unreliable in either or both the “transmit” or “receive” modes of operation.
Even micron-sized particles of dust, debris or other contaminants that settle on or are attracted to the optical surfaces, which coat or block even a portion of the light path, will greatly diminish the optical strength of a signal passing to or from the optoelectronic element. Similarly, if there are lenses or other optical elements in the light path, each of these optical elements may collect dust, particulate contamination, moisture, or a film of contamination on any or all the optical surfaces thereof, and thus prevent the efficient passage of light therethrough. Lasers are very sensitive to moisture, and reflective coatings on facets of some types of lasers, such as a DFB (distributed feedback) laser, are sensitive to condensed moisture as the condensate acts to interfere with the passage of the laser signals therethrough. Similarly, changes in the ambient pressure can distort or disrupt the very sensitive configurations or alignments of these highly sensitive electrical and optical components of a media converter module.
The use of media converter modules continues to expand into various fields, including harsh and hazardous environments. These harsh environments include oil, gas and water, such as with submarine deployments. These harsh environments are often challenged by the inability to protect the sensitive optical coupling elements, such as the interface of the laser and detector devices from the ingress of very high pressure fluids such as seawater or oil. Similarly, when it is necessity to join optical fibers at a connector interface of a media converter module in a marine environment, there can be great difficulties managing cleanliness and pressure differentials to provide reliable and repeatable optical connection performance.
Accordingly, there is a need for a media converter module design that can reliably function and be connected to surrounding wire, electrical and optical connectors and cables in harsh environments, including environments experiencing high ambient pressure differentials.
In accordance with the present invention, a hermetically sealed media converter apparatus is provided that is designed to operate in high pressure differential environments, such as deep marine environments. In addition to high-pressure differential environments, the hermetically sealed media converter apparatus of the present invention also is designed to operate in harsh ambient environments such as used in oil and gas production equipment. The hermetically sealed media converter apparatus of the present invention is specifically designed to protect its sensitive electrical and optical internal components in harsh ambient pressure differential environments.
In accordance with the present invention, a hermetically sealed media converter apparatus is provided having a vessel forming an inner chamber that is hermetically sealed from the surrounding ambient environment outside the vessel. A media converter module is contained within the inner chamber having several elements, for example, an opto-detector, a laser transmitter, an electrical transmitter, and an electrical receiver. A hermetic wire or multiples of wire that may be part of a continuous wire cable as a hermetically sealed feedthrough located at a first position on the vessel enabling a transmit wire or wires and/or a receive wire or wires to pass through the first feedthrough of the vessel and connect to the electrical transmitter and/or electrical receiver within the vessel, respectfully, while maintaining the hermetic seal of the inner chamber of the vessel from the surrounding ambient environment. A hermetic optical fiber feedthrough is located at a second entry of the same vessel enabling an optical fiber or fibers also to pass through the vessel, while maintaining the hermetic seal of the inner chamber of the vessel from the surrounding ambient environment. Other wire elements such as those conducting power or monitoring data to and from the media converter within the vessel also may be provided for by supplementary hermetic feedthroughs at some other entry/exit points to the vessel.
The foregoing has outlined, rather broadly, the preferred features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention and that such other structures do not depart from the spirit and scope of the invention in its broadest form.
a-e illustrate further embodiments of the block diagram shown in
Referring now to the drawings,
The first end or flange 14 is preferably soldered, brazed, welded or glued to an open end of the vessel 12 to form a hermetic seal. The flange 14 also can be hermetically or fluid or liquid or gas tight sealed to an open end of the cylindrical vessel 12 by other known techniques, such as screws or bolts in combinations with rubber O-rings or C-rings. The second end, flange or plate 16 also is hermetically liquid or gas tight sealed to the opposing open end of the vessel 12. The flange 16, similar to flange 14, is hermetically sealed to the other end of vessel 12 by a known technique, described above. Bolts 18 are shown as one of many examples for securing the flange 16 to the end of the vessel 12 to form a hermetic seal.
On the electrical side of the media conversion circuitry 70, electrical wires 80 pass through the hermetic electrical feedthrough 81 and to the electrical transmit media conversion circuitry 71, and electrical wires 82 pass through the hermetic electrical feedthrough 83 and connect to the electrical receive media conversion circuitry 73.
In accordance with a further important aspect of the present invention, the hermetically sealed vessel 102 maintains a consistent Pressure 2 (P2) which is not affected by changes in the external ambient Pressure 1 (P1). The internal Pressure 2 (P2) can be close to a vacuum, pressure approximate at sea level, or a pressure exceeding sea level, whatever pressure is desired to be maintained by a user, which is independent of changes in the ambient pressure P1.
Turning now to other components within the media converter apparatus 100, a hermetic electrical feedthrough 108 and a hermetic optical feedthrough 110 are hermetically sealed on opposing open ends of the vessel 102 and in some embodiments could be the same end or penetration point of the vessel, which preferably has a cylindrical configuration. Electrical wires 111 pass through the hermetic electrical feedthrough 108 into the hermetically sealed inner chamber 103 of the vessel 102 and connect to the media conversion circuitry 104. These wires could similarly be entering and exiting the vessel through the same hermetic penetration element as the optical fibers in some configurations. Similarly, optical fibers 112 pass through a hermetic optical feedthrough 110 from the ambient environment having pressure P1 to the inner chamber 103 having pressure P2, and connect to the media conversion circuitry 104.
In accordance with an additional aspect of the present invention, a diagnostic circuit 106 is included within the inner chamber 103 to be connected to and monitor operation of the media conversion circuitry 104. The diagnostic circuit is 106 is connected to a system controller via a communication wire 121 passing through the hermetic electrical feedthrough 108. A temperature sensor or temperature transducer 107 is located within the inner chamber 103 to monitor the temperature within the inner chamber 103. The temperature sensor 107 is connected to a system controller via a communication wire 122 passing through the hermetic electrical feedthrough 108. A pressure sensor or pressure transducer 108 is located within the inner chamber 103 to monitor pressure within the inner chamber 103. The pressure sensor 108 is connected to a system controller via a communication wire 123 passing through the hermetic electrical feedthrough 108.
A DC/DC transformer 114 receives power via the hermetic electrical feedthrough 108 and provides power to the media conversion circuitry 104. On the electrical side of the media conversion circuitry 104, electrical wires 111 are first received by isolation transformers 115,116, which in turn are electrically connected to Ethernet chip sets 117,118. Similarly, optical fibers 112 pass through the hermetic optical feedthrough 110 and connect to optoelectronic transceivers 119,120, which are electrically connected to the Ethernet chip sets 117,118.
On the electrical side of the media conversion circuitry 70, electrical wires 80 pass without interruption through the hermetic electrical feedthrough 81 and to the electrical transmit media conversion circuitry 71, and electrical wires 82 pass without interruption through the hermetic electrical feedthrough 83 and connect to the electrical receive media conversion circuitry 73.
In accordance with the present invention, a hermetically sealed media conversion apparatus is provided having hermetic feedthroughs or penetrators enabling electrical wires and optical fibers to pass through the outer walls of the vessel unobstructed and continuous without performance loss so as to maximize transmission efficiency while maintaining a hermetical seal in high pressure ambient environments. Optical fibers and electrical wires pass through the feedthroughs without any change to the fiber or wire, such as splicing or passing through a connector. The feedthroughs are essentially “transparent” to electrical wires and optical fibers passing therethrough because the electrical wires and optical fibers pass through unaffected. This design enables optical fibers to avoid virtually any no attenuation or change in polarization of transmitted light signals or general performance degradation. The feedthrough or penetrator 83 enables electrical wires to pass through the end wall 14 while maintaining a hermetic seal capable of withstanding high pressure ambient environments, such as 20 k PSI. When referring to “feedthroughs” or “penetrators” in this application, the inventors have defined these terms to means locations where electrical wires or optical fibers pass through the outer walls of the vessel unobstructed and continuous so as to maximize transmission efficiency of electrical wires and optical fibers while maintaining a hermetical seal in high pressure ambient environments.
As illustrated in
The feedthrough 83 preferably is constructed of metal having a low coefficient of expansion. The copper conductors 98 within the feedthrough 83 have been stripped of their insulation 91. A low melting point glass 96 preferably fills gaps between each of the copper conductors 98 located within the feedthrough 83. The low melting point glass 96 also fills gaps between the copper conductors 98 and an inner wall 93 of the feedthrough 83. In other embodiments the low melting point glass 96 can be replaced with a ceramic or epoxy or any other sealing material known for forming an hermetic seal around copper conductors.
Feedthroughs are produced by sealing onto the conductor itself. Sealing to the fiber or wire jacket will not generate a ‘hermetic’ feed through. The outer protection jackets or insulators have to be locally ‘window stripped’ by chemical or mechanical processes with great care and complexity without damage to the conductor to expose a short length of the electrical or optical conductor onto which a seal can be made between the vessel and the conductor itself. It is preferable to maintain the full protection of the conductor on both sides of the hermetic seal, hence also the ‘window stripping’ technology. The insulator 91 surrounding the copper conductors 98 outside of the vessel 12 and the feedthrough 83 preferably are constructed of a polymer effective for protecting and insulating the copper conductors 93 for a specific ambient environment, such a deep sea water or pressure balancing dielectric oil.
In accordance with the present invention, the cladding and/or protection sheathing 102 remains on the plurality of optical fiber cores 100 immediately before and after the optical feedthrough 28. Within the feedthrough 28, the cladding 102 on the cores 100 of the optical fibers 30 is stripped, and the optical cores 100 are hermetically sealed within an aperture 107 of the optical feedthrough 28. A hermetic seal is achieved within a gap 101 of the aperture 107 between the optical cores 100 and a wall 109 of the aperture 107 of the optical feedthrough 28 using a glass solder or melting glass 105 to fill the gap 101. The glass 105 filling the gap 101 and forming a high pressure hermetic seal between the bare core 100 and the inner wall 109 of the aperture 107 in the optical feedthrough 28 is a low melting point glass alloy. The glass alloy 105 is tailored to closely match the coefficient of thermal expansion (CTE) of the core glass 100 in the optical ribbon fibers 30. The glass 105 seals to the core glass fibers 100 and the inner wall 109 allowing for the hermetic seal. The glass alloy 105 properties allow for the hermetic seal formed in the feedthrough 28 to be maintained over temperature cycling and high pressure differences.
A high compression annular seal is formed by the melted glass 105 within the gap 101 between the core 100 and the inner wall 109 of the aperture 107. The glass 105 has a low coefficient of thermal expansion (CTE), thereby creating a hermetic seal, after the glass cools, that is very compressive between the core 100 and the inner wall 107. This characteristic creates a highly durable hermetic seal capable of withstanding high pressure differentials and high pressure ambient environments. Moreover, this process of glass soldering directly to the core 100 enables the feedthrough 28 to provide a high pressure hermetic seal, while further enabling the optical core 100 to pass through the end wall 16 without obstructing, splicing, or affecting the efficiency of the optical transmission medium.
While specific embodiments have been shown and described to point out fundamental and novel features of the invention as applied to the preferred embodiments, it will be understood that various omissions and substitutions and changes of the form and details of the apparatus illustrated and in the operation may be done by those skilled in the art, without departing from the spirit of the invention.
This is a Continuation-in-Part (CIP) application of application Ser. No. 14/205,348, filed on Mar. 11, 2014, which is a continuation-in-part of application Ser. No. 13/109,966, filed on May 17, 2011, which claims priority to provisional patent application No. 61/345,323, filed on May 17, 2010, and all patent applications set forth above in this paragraph are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61345323 | May 2010 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14205348 | Mar 2014 | US |
| Child | 15006058 | US | |
| Parent | 13109966 | May 2011 | US |
| Child | 14205348 | US |
