The present disclosure relates generally to optical interconnect components.
Since the inception of microelectronics, a consistent trend has been toward the development of optoelectronic circuits, such as optical interconnects. This may be due, at least in part, to the fact that optoelectronic circuits may offer advantages over typical electronic circuits, such as, for example, a much larger bandwidth (by many orders of magnitude). Such optoelectronic circuits often involve the transmission of optical signals, and the interconversion of such optical signals into electronic signals. In some instances, performing optical signal transmission involves a waveguide. Optical waveguides are commonly made with glass or polymers. Extraction of a fraction of the guided signal with these solid waveguides typically requires complicated tapping structures. Some waveguides are hollow metal structures. Optical signals propagate in air through such structures, and as such, stringent alignment and collimation are required for proper signal transmission.
Features and advantages of embodiments of the present disclosure will become apparent by reference to the following detailed description and drawings, in which like reference numerals correspond to the same or similar, though perhaps not identical, components. For the sake of brevity, reference numerals having a previously described function may or may not be described in connection with subsequent drawings in which they appear.
Embodiments of the optical interconnect components disclosed herein include various waveguides which are configured to enable flexible topographical arrangements for the layout and routing of signal paths.
The waveguide 12 and tap 14 may be formed of any material that is capable of receiving and propagating light beams of a particular wavelength (ranging from 450 nm to 1.5 microns). As such, the desirable wavelength or range of wavelengths to be propagated may dictate the materials selected for the waveguide 12. It is to be understood that the waveguide 12 and tap 14 may be the same or different materials. In a non-limiting example, the waveguide 12 and/or tap 14 is formed of glass, polymeric material(s) (e.g., polycarbonate, polyamide, acrylics, etc.), silicon, or another like material. The waveguide(s) 12 and tap(s) 14 are generally in the form of a fiber, and thus are not hollow. In some instances, the waveguides 12 and taps 14 are in the form of a multi-mode fiber with a circular or rectangular cross-section. These types of fibers may consist of a core and a clad. The diameter of the core of each of the waveguide 12 and the tap 14 ranges from about 10 microns to about 1000 microns.
In some instances, the waveguide 12 and/or tap 14 is composed of holey or microstructured fibers. Such holey fibers have a substantially regular arrangement of air holes extending along the length of the fiber to act as a cladding layer. The core is generally formed by a solid region in the center of the substantially regular arrangement of air holes, or by an additional air hole in the center of the substantially regular arrangement of air holes. The effective refractive index of such fibers is determined by the density of the holes. As such, the holes may be arranged to change the effective index of the waveguide 12 and/or tap 14. The core of holey fibers will generally have a lower density of holes than the cladding layer, and thus, the effective index of the core is generally higher than that of the cladding.
In some instances, the waveguide 12 and tap 14 of the optical interconnect component 10 are made with the same core material and the same clad material. The desirable refractive index will depend, at least in part, on the wavelength or range of wavelengths of light to be transmitted through the component. In one non-limiting example, each of the waveguide(s) 12 and tap(s) 14 has a core with an index of refraction of about 1.51 and a cladding layer thereon with an index of refraction of about 1.49.
The component 10 shown in
The surface SW is configured at an angle θ1 that is equal to or less than 90° relative to the axis A. In a non-limiting example, θ1 ranges from about 30° to about 60°. As shown in
When it is desirable to form the surface SW at an end E, the waveguide 12 is cut so that a desirable end E is tapered to the desirable angle. In one non-limiting example, the waveguide 12 is cut using a thermal molding or hot embossing process, similar in principle to processes used to fabricate vinyl records. Molding or embossing is relatively cost effective and reliable. In another non-limiting example, ultraviolet (UV) imprinting could also be used to cut the waveguide 12.
When it is desirable to form the surface SW a spaced distance from the ends E, a gap G may be formed in the waveguide 12 to expose the angled waveguide surface SW. In the example shown in
As previously mentioned, the gap G is adjacent to the surface SW, but the gap G is also adjacent to at least one other surface S of the waveguide 12. The angle of this other surface S will depend, at least in part, on the angle θ1 of the surface SW. As will be discussed further hereinbelow, an axis AT of the tap 14 is positioned at an angle θ2 (relative to the axis AW of the waveguide 12) that is two times the angle of the angled surface of the tap 14, which is substantially identical to the angle θ1 of the waveguide angled surface SW. As such, the angle (relative to the axis AW of the waveguide 12) of the other surface S that is adjacent to the gap G is two times the angle θ1 of the angled waveguide surface SW. In the example shown in
The fabrication of the optical component 10 also includes adhering tap(s) 14 to the exposed surface(s) SW. The adhered tap(s) 14 are shown in
In the embodiments shown and discussed in the
The tap 14 also includes the axis AT positioned at the angle θ2 that is two times the angle of the angled surface ST. In some instances, it is desirable that the reflected light beams be centered along the axis AT of the tap 14. This is accomplished when the angle θ2=2×θ1. As shown in
As shown in the embodiment which begins at
Prior to adhering the tap 14 to the waveguide 12, an at least partially reflective coating 16 is established on the angled surface ST of the tap 14. The percentage of reflectivity and the pattern in which the partially reflective coating 16 is established depend, at least in part, on the desirable beam splitting properties at the interface between the surfaces SW, ST, at which the coating 16 is positioned. In some instances, the coating 16 is partially reflective (i.e., less than 100% reflective) and is established on the entire tap angled surface ST. In other instances, the coating 16 is 100% reflective, and is established on portions of the tap angled surface ST (e.g., in a dotted, striped or other like pattern). In still other instances, some portions of the coating 16 are 100% reflective, while other portions of the coating 16 are less than 100% reflective. Light beams impinging on the reflective portions of the coating 16 will be redirected into the tap 14, and light beams impinging on the less or non-reflective portions of the coating 16, or those areas of the tap angled surface ST not including the coating 16 will continue to pass through the waveguide 12 (see, for example,
Non-limiting examples of suitable materials for the partially reflective coating 16 include aluminum, silver or another material that is a reflector of the selected wavelength of light established at a thickness that is less than or equal to 0.01 microns. Non-limiting examples of suitable materials for the fully reflective coating 16 include aluminum, silver or another material that is a reflector of the selected wavelength of light established at a thickness that is greater than or equal to 1 micron. Such materials may be established via any suitable technique, including, but not limited to standard vacuum deposition techniques (e.g., thermal or e-beam evaporation, sputtering, etc.).
In either of the methods disclosed in
Referring now to
While not shown in the Figures, one or more detectors may be positioned to detect some or all of the light beams exiting the optical components 10.
In one non-limiting example, when the waveguide 12 and tap 14 each has an index of refraction of about 1.5, and the waveguide 12 is about 30 cm long, it may be desirable to maintain the skew of clock pulses to <20 ps over the waveguide length. This may be accomplished when the maximum light beam external angle (i.e., outside the waveguide 12) is less than about 7°, and the maximum light beam internal angle (i.e., inside the waveguide 12) is less than about 5°. It is to be understood that the values in this example are approximate desirable values, and that they are dependent, at least in part, upon the index of refraction of the materials, the length of the waveguide 12, and the operating data rate.
As depicted in
While not shown, it is to be understood that each of the components 10 in the system 100′ has a light source 18 directing light beams to the respective waveguides 12. An individual lens 20 may also be utilized to direct the light beams from one light source 18 to the corresponding waveguide 12. The arrows shown in
The other end E2 of the waveguide 12 is operatively connected to a second waveguide 24 such that an interface I is formed therebetween. The surfaces of the waveguides 12, 24 at this interface I have the same angle with respect to the axis AW of the waveguide 12. The interface I may have the at least partially reflective coating 16 established in a manner that achieves the desirable transmissivity and reflectivity of the light beams. In this instance, the waveguides 12, 24 may be formed of the same materials and have the same index of refraction. These surfaces may be adhered via an index matching glue.
This embodiment of the optical system 100″ includes a third waveguide 26 positioned such that any reflected light beams from the interface I are directed into the waveguide 26. As such, the position of the third waveguide 26 will depend, at least in part, on the configuration of the surfaces at the interface I. In one example, the waveguide 26 may be, stacked on the other waveguides 12, 24 such that a surface S26 thereof receives the reflected light beams. This surface S26 may be tapered at any desirable angle. In one instance, the angle of the surface S26 may be configured so that total internal reflection occurs within this waveguide 26. As a non-limiting example, the waveguide 26 is formed of glass with an index of refraction of 1.5, and the medium adjacent the angled surface S26 is air; as such, the surface S26 may have an angle larger than 41.8° (e.g., 45°) and total internal reflection will occur. Instead of configuring the angle of the surface S26 to achieve total internal reflection, it is to be understood that a reflective coating may be established on the surface S26.
It is to be understood that a clad layer 22 (not shown in this Figure) may also be positioned between the third waveguide 26 and the waveguides 12, 24 upon which it is established. Such a clad layer does not interfere with the reflected light beams traveling from the interface I to the third waveguide 26.
Due to the flexibility in the materials used for the waveguides 12, 24, 26 and taps 14, a number of different light beam paths may be achieved. While straight waveguides 12, 24, 26 and taps 14 are shown in the figures, it is to be understood that the waveguides 12, 24, 26 and/or taps 14 may include bends and or curves. Furthermore, multiple components 10 may be configured in parallel to obtain a ribbon optical connector.
Clause 1: A component for an optical interconnect, comprising:
a waveguide having at least one surface that is configured at an angle equal to or less than 90° relative to an axis of the waveguide;
a tap operatively connected to the waveguide, the tap having an angled surface that is adhered to the angled surface of the waveguide, wherein an angle of the angled surface of the tap is, substantially identical to the angle of the angled surface of the waveguide, and an axis of the tap is positioned at an angle that is two times the angle of the angled surface of the tap; and
an at least partially reflective coating established on at least a portion of the angled surface of the tap.
Clause 2: The component as defined in clause 1 wherein the angled surface of the tap having the at least partially reflective coating established on the at least the portion is a beam splitter.
Clause 3: The component as defined in any of clauses 1 or 2 wherein the tap is operatively positioned in a gap formed in the waveguide.
Clause 4: The component, as defined in any of clauses 1 through 3 wherein the waveguide has an other surface configured at an angle equal to or less than 90° relative to the axis of the waveguide, and wherein the component further comprises:
an other tap operatively connected to the waveguide via an angled surface that is adhered to the other angled surface of the waveguide, wherein an angle of the angled surface of the other tap is substantially identical to the angle of the other surface of the waveguide, and an axis of the other tap is positioned at an angle that is two times the angle of the angled surface of the other tap; and
an other partially reflective coating established on at least a portion of the angled surface of the other tap.
Clause 5: The component as defined in clause 4 wherein the tap is operatively positioned iii a gap formed in the waveguide, wherein the other tap is operatively positioned in an other gap formed in the waveguide, wherein the gap and the other gap are positioned a predetermined distance from each other along a length of the waveguide, and wherein the axis of the tap is parallel to the axis of the other tap.
Clause 6: The component as defined in any of clauses 4 or 5 wherein the other tap includes a second angled surface configured to receive a light beam from the angled surface of the other tap and to redirect the received light beam about 90°.
Clause 7: The component as defined in any of clauses 1 through 6 wherein the at least partially reflective coating is less than 100% reflective and is established on the entire angled surface of the tap.
Clause 8: The component as defined in any of clauses 1 through 6 wherein the at least partially reflective coating is 100% reflective and is established on a portion of the angled surface of the tap.
Clause 9: The component as defined in any of clauses 1 through 8 wherein an end of the waveguide is configured at a 45° angle relative to the axis of the waveguide, and wherein the component further comprises:
a second waveguide having an end configured at a 45° angle that is operatively connected to the waveguide at the angled end; and
a third waveguide established on at least a portion of the waveguide and the second waveguide, the third waveguide including a 45° angled surface that is configured to redirect a light beam from an intersection at which the angled ends of the waveguide and the second waveguide meet and incident on the 45° angled surface about 90°.
Clause 10: A method of making the component as defined in any of clauses 1 through 8, the method comprising:
establishing the at least partially, reflective coating on the at least the portion of the angled surface of the tap;
cutting the waveguide, thereby forming the angled surface of the waveguide; and
adhering the angled surface of the tap to the angled surface of the waveguide.
Clause 11: The method as defined in clause 10 wherein the cutting the waveguide i) is accomplished by inserting the tap into the waveguide or ii) includes forming a gap in the waveguide that is configured to receive the tap.
Clause 12: The method as defined in any of clauses 10 or 11 wherein prior to adhering, the method further comprises establishing an index matching adhesive material on the angled surface of the tap, the angled surface of the waveguide, or a surface of the tap that is parallel to the axis of the tap.
Clause 13: An optical system, comprising:
a light source; and
an optical component configured to have light beams input therein from the light source, the optical component including:
Clause 14: The optical system as defined in clause 13, further comprising a lens positioned between the light source and the optical component, the lens configured to direct the light beams from the light source into the waveguide of the optical component.
Clause 15: The optical system as defined in any of clauses 13 or 14 wherein the waveguide has an other surface configured at an angle equal to or less than 90° relative to the axis of the waveguide, and wherein the component further comprises:
an other tap operatively connected to the waveguide via an angled surface that is adhered to the other angled surface of the waveguide, wherein an angle of the angled surface of the other tap is substantially identical to the angle of the other surface of the waveguide, and an axis of the other tap is positioned at an angle that is two times the angle of the angled surface of the other tap; and
an other partially reflective coating established on at least a portion of the angled surface of the other tap.
Clause 16: The optical system as defined in any of clauses 13 through 15, further comprising:
a plurality of other light sources;
a plurality of other optical components, each one of the other optical components configured to have light beams input therein from one of the plurality of other light sources, each of the other optical components including:
a cladding layer separating each optical component from an adjacent optical component, the cladding layer having an index of refraction that is lower than an index of refraction, of the waveguides and the taps of each of the plurality of other optical components.
Clause 17: The optical system as defined in clause 16, further comprising a plurality of lenses, each of the plurality of lenses positioned between one of the light sources and one of the optical components, each of the lenses configured to direct the light beams from the one of the light sources into the waveguide of the corresponding one of the optical components.
While several embodiments have been described in detail, it will be apparent to those skilled in the art that the disclosed embodiments may be modified. Therefore, the foregoing description is to be considered exemplary rather than limiting.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US2008/082110 | 10/31/2008 | WO | 00 | 4/29/2011 |