OPTICAL FIBER COUPLER AND ALIGNMENT METHOD

There is provided an optical coupler system. The system includes a first lens module including a first lens array positioned adjacent an emitting source. The first lens includes one or more collimating lenses. The system further includes a second lens module coupled to the first lens module. The second lens module may include alignment features. The system further includes a second lens array and an optical redirecting device providing a downstream second optical output, and an optical fibre cable integrally coupled to the second lens module.

FIELD

Embodiments of the present disclosure generally relate to the field of optical communications, and in particular to optical fiber coupler devices and alignment methods.

BACKGROUND

Optical fiber coupler devices may be optical devices for propagating optical signals from a first device to a second device. For example, optical fiber coupler devices may connect two or more optical fiber ends allowing the transmission of optical signals across optical fibers. In another example, optical fiber coupler devices may propagate optical light emerging from a source emitter to an optical fiber cable for downstream optical light transmission. Optical fiber coupler devices may include one or more lenses through which optical light may pass.

SUMMARY

The present disclosure describes embodiments of optical fiber coupler devices for propagating optical light to an end of an optical fiber for downstream optical signal transmission. In some scenarios, embodiments of optical fiber coupler devices may be for connecting two optical fiber ends allowing transmission of optical signals across the optical fibers.

When light energy density is relatively high (e.g., focused optical light) at an interface between adjacent mediums, an alignment tolerance specification associated with aligning mediums at the interface may be relatively stringent.

For example, when an optical fiber coupler provides focused light output at a coupler output to an optical fiber, the extent that the coupler output is precisely aligned with the optical fiber end may affect the optical light signal quality for downstream propagation. It may be desirable to provide optical fiber coupler devices for propagating optical light across adjacent mediums whilst reducing the stringent nature of the alignment tolerance specification. Further, it may be desirable to provide optical fiber coupler devices with features for allowing production line quality control testing of lens modules included in the optical fiber coupler devices.

The present disclosure describes embodiments of optical fiber coupler devices including lens configurations for reducing light energy density at an interface between lens modules, and for propagating the optical light into ends of optical fibers for downstream optical light transmission. Accordingly, a misalignment tolerance specification at the interface between lens modules need not be as stringent as compared to when light energy density at an interface between adjoining mediums may be comparatively higher. Based on embodiments described in the present disclosure, increased manufacturing or assembly yields of optical fiber couplers to optical fibers may be achieved.

In an aspect, the present disclosure provides an optical fiber coupler system comprising elements described and/or illustrated in the present disclosure.

In another aspect, the present disclosure provides an optical fiber coupler method comprising operations described an/or illustrated in the present disclosure.

In another aspect, the present disclosure provides an optical fiber coupler system. The optical fiber coupler system includes a first lens module including a first lens array positioned adjacent an emitting source, the first lens module including one or more collimating lenses providing a first optical output having reduced optical light energy density as compared to optical light emerging from the emitting source; a second lens module coupled to the first lens module, the second lens module including: alignment features aligning the second lens module with the first lens module at the interface region, wherein the optical light energy density at the interface region is lower as compared to optical light emerging from the emitting source; and a second lens array including one or more focusing lenses and an optical redirecting device providing a downstream second optical output; and an optical fiber cable integrally coupled to the second lens module to receive the second optical output.

In this respect, before explaining at least one embodiment in detail, it is to be understood that the embodiments are not limited in application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.

DESCRIPTION OF THE FIGURES

In the figures, embodiments are illustrated by way of example. It is to be expressly understood that the description and figures are only for the purpose of illustration and as an aid to understanding.

DETAILED DESCRIPTION

Optical coupler systems may include devices for transmitting optical signals from a first medium to a second medium. As an example, a laser emitting device emitting divergent light may be coupled for transmission along an optical fiber. Optical coupler systems including lens modules may be provided as an optical path design for transmitting light signals from a first end point to a second endpoint.

Reference is made toFIG.1, which illustrates a schematic view of an optical coupler system100, in accordance with an embodiment of the present disclosure. The optical coupler system100includes a lens module120for coupling optical signals from a emitting source110to a optical fiber cable130. The optical fiber cable130may include one or more optical fibers configured to transmit light.

In some examples, the emitting source110may be a laser beam device. Other types of emitting sources110may be used. The emitting source110may provide divergent light output.

The lens module120may include a collimating lens122and a focusing lens126configured to couple optical signals from the light emitting source110to the optical fiber cable130. In some embodiments, the lens module120may include a redirecting device124configured to alter direction of optical signals. In some embodiments, the redirecting device124may be configured for redirecting optical signals by substantially 90 degrees. Other redirecting devices124for redirecting optical signals by other angles may be used.

Thus, in some implementations, the optical coupler system100may include one or more optical components coupling an emitting source110and an optical fiber array. The emitting source110may be a vertical-cavity surface-emitting laser (VCSEL) chip array to emit light signals for transmission by the optical fiber cable130. The optical fiber cable130may include an array of optical fibers positioned parallel to one another and fixed on an optical fiber carrier device. The optical fiber carrier device may be aligned based on a series of guiding apertures and guiding posts. In the present example, the lens module120having the one or more optical components and the optical fiber carrier device may be constructed based on injection molding operations.

In some example injection molding operations, specifications for producing guide apertures may have a guide aperture diameter tolerance range of 0 to 5 μm. Specifications for producing guide columns may have a guide column diameter tolerance range of −5 to 0 μm. As it may be desirable to have matching properties, the tolerance of a device feature may be positive, while the tolerance of a corresponding feature may be negative. In the present example, specifications for the position of one or more guide holes and one or more corresponding guide columns may be have a tolerance range of −5 μm to 5 μm. In some scenarios, additive tolerance ranges may cause the positioning of optical fibers relative to corresponding lenses to be eccentric. Thus, the mismatch in position among respective optical fibers and corresponding lenses may exceed 10 μm.

As light entering an optical fiber cable130may be focused light having relatively focus spot light energy density, such observed eccentricity among respective optical fibers and corresponding lenses may result in reduced component alignment thereby leading to reduced optical coupler system production yields.

Further, in scenarios where optical coupler systems may be produced based on injection moulding processes, guide holes or guide posts constructed of plastic materials may be susceptible to deformation, thereby affecting a desired roundness or verticality of the optical coupler system setup. In scenarios where guide posts are damaged, there may be greater quantities of material waste and reduction of optical coupler system production yields.

Based on the example optical coupler system100described with reference toFIG.1, misalignment of the lens module120output relative to an adjoining optical fiber130may lead to unstable propagation of optical signals to the optical fiber130. That is, eccentricity among respective optical fibers and corresponding lenses of the lens module120may result in reduced optical coupler system production yields at least because optical signals may not be successfully transmitted from the emitting source110onward to the optical fiber130.

In some scenarios, when light energy density is relatively high (e.g., focused optical light) at an interface between adjacent mediums, an alignment tolerance specification associated with aligning mediums at the interface may be relatively stringent.

For example, when an optical fiber coupler provides focused light output at a coupler output to an optical fiber, the extent that the coupler output is precisely aligned with the optical fiber end may affect the optical light signal quality for downstream propagation. It may be desirable to provide optical fiber coupler devices for propagating optical light across adjacent mediums whilst reducing the stringent nature of the alignment tolerance specification. Further, it may be desirable to provide optical fiber coupler devices with features for allowing production line quality control testing of lens modules included in the optical fiber coupler devices.

Reference is made toFIG.2, which illustrates a schematic view of an optical coupler system200, in accordance with another embodiment of the present disclosure. The optical coupler system200includes a first lens module220and a second lens module230.

The first lens module220includes a collimating lens222for receiving optical signals from an emitting source210. The first lens module220receives divergent light from the emitting source210and provides a first optical output224. The first optical output224may include aligned optical signals (akin to parallel beams of light signals). The first optical output224may have a light energy density that is relatively lower as compared to the light energy density emitted by the emitting source210.

In some embodiments, the second lens module230includes a focusing lens232for receiving the first optical output224. The region between the first optical output224and the focusing lens232may be an interface region between the first lens module220and the second lens module230.

The focusing lens232in combination with an optical redirecting device234may redirect the first optical output224to provide a second optical output236at an opening of an optical fiber240. In some embodiments, positioning of the focusing lens232relative to the optical redirecting device234may be adjusted to provide alignment of the second optical output236and the opening of the optical fiber cable240at the interface of the second lens module230and the optical fiber cable240.

In some embodiments, the optical redirecting device234may redirect optical light by approximately 90 degrees. In some other embodiments, the optical redirecting device234may redirect optical light other degree values based on a required physical configuration of the optical fiber coupler device.

To provide substantially precise alignment of the second optical output236at the opening of the optical fiber cable240, in some embodiments, the second lens module230may integrally position the focusing lens232and the optical fiber cable240based on injection molding operations. Accordingly, the optical fiber cable240may be affixed to an alignment position relative to the second lens module230.

Reference is made toFIG.3, which illustrates a perspective view of the first lens module220coupled to the second lens module230, in accordance with embodiments of the present disclosure. The combination of the first lens module220and the second lens module230may be configured to convey optical signals from an emitting source (not explicitly shown inFIG.3) to the optical fiber cable240having a plurality of optical fibers. In some embodiments, the first lens module220may be removably affixed to the second lens module230.

To couple optical signals from an emitting source210to the optical fiber cable240with substantially precise alignment, it may be desirable to provide optical coupler system features for aligning the first lens module220and the second lens module230.

To illustrate,FIG.4shows a top perspective view of the first lens module220(FIG.2). The first lens module220includes one or more guiding apertures426and an optical output slot428through which the first optical output224(FIG.2) may emerge towards the second lens module230.

FIG.5illustrates a bottom perspective view of the first lens module220. The first lens module220may be formed from an injection molded frame, and may include a first lens array550. The lens array550may include one or more collimating lenses222for receiving optical signals from the emitting source210(FIG.2). For example, the one or more collimating lenses222may be for receiving optical signals from a respective emitting source210.

The first lens module220may include one or more guiding columns552. The one or more guiding columns552may be configured to align with substrate apertures (not explicitly illustrated inFIG.5). The substrate apertures may be on a substrate, and the substrate may be configured to receive the first lens module220thereon. As an example, the substrate may be a printed circuit board having one or more emitting sources210positioned thereon. Alignment of the one or more guiding columns552(of the first lens module220) with respective substrate apertures may thereby align the one or more emitting sources210with respective collimating lenses222of the lens array550.

The first lens module220may include one or more reference planes554. The one or more reference planes554may provide a surface on which the first lens module220may interface with an adjoining substrate. In some embodiments, the one or more reference planes554may be dimensioned such that the respective collimating lenses222are positioned at a substantially similar distance to the corresponding emitting source210as adjacent collimating lenses222in the lens array550.

Reference is made toFIG.6, which illustrates a top perspective view of the second lens module230(FIG.2). The second lens module230includes the redirecting device234(FIG.2). As described herein, the redirecting device234may be configured in combination with the focusing lens232(FIG.2) for receiving the first optical output224and redirecting the optical signal to the optical fiber cable (not explicitly shown inFIG.6). In some embodiments, the optical fiber cable may be integrally affixed in an alignment position relative to the second lens module230such that the first optical output224may be received, refocused, or redirected by the combination of the focusing lens232and the redirecting device234into a respective optical fiber of the optical fiber cable.

The second lens module230includes one or more peripheral fiber grooves660for positioning an end of a respective optical fiber adjacent to the redirecting device234.

FIG.7illustrates a bottom perspective view of the second lens module230. The second lens module230includes a second lens array770. The second lens array770includes one or more focusing lenses232configured for receiving the first optical output224.

The second lens module230may include guiding protrusions780configured for being received within corresponding one or more guiding apertures426(FIG.4) of the first lens module220. Alignment and receipt of the guiding protrusions780with corresponding guiding apertures426positions the second lens module230relative to the first lens module220such that first optical output224from the first lens module220is aligned with and received by respective focusing lenses232of the second lens array770.

The second lens module230may include one or more proximal fiber grooves790for positioning the end of the respective optical fiber adjacent to the redirecting device234. By positioning the end of the respective optical fiber adjacent to the redirecting device234, the second optical output236(FIG.2) may be provided to and transmitted along one or more optical fiber components.

In some embodiments, optical fiber cable240may include one or a bundle of optical fibers. Beginning at an end portion of the respective optical fibers, diameters of the respective fibers may progressively increase. For example, the optical fibers may have a 125 μm diameter at end portions of the respective fibers, and may have a 245 μm diameter inward from the end portion of the respective fibers.

In some embodiments, the one or more proximal fiber grooves790may be configured as V-shaped grooves, and may be configured for positioning or fixing a smaller diameter portion of the optical fiber. Further, the one or more peripheral fiber grooves660(FIG.6) may be configured for positioning or fixing a larger diameter portion of the optical fiber. Continuing with the above example, the one or more peripheral fiber grooves660may be configured for positioning or fixing a 245 μm portion of the optical fibers, and the one or more proximal fiber grooves790may be configured for positioning or fixing a 125 μm diameter end portion of the respective optical fibers. Other optical fiber end dimensions may be used.

In some embodiments, the second lens array770may include the combined focusing lens232and the redirecting device234having a corresponding mapping to a grove of the one or more proximal fiber grooves790. Based on features of the second lens module230, observed eccentricity caused by the injection molding operations among respective optical fibers and corresponding lenses of the second lens array770may be minimized to a tolerance of approximately +/−2 μm.

Because the one or more proximal grooves790are on a similar side as the second lens array770, in some scenarios, production line test and inspection of alignment of the respective optical fibers relative to the second lens array770may be conducted with relative ease.

As described, the one or more peripheral fiber grooves660(FIG.5) may be configured for positioning or fixing a 245 μm (e.g., larger diameter portion of the optical fibers) portion of the optical fibers, and may provide the structural components for guiding optical fibers into the second lens module230.

FIG.8shows a bottom plan view of the second lens module230(FIG.2). InFIG.8, a plurality of optical fibers of the optical fiber240are shown to be received by the combination of peripheral grooves660(not explicitly shown inFIG.8) and the proximal grooves790.

FIG.9shows a cross-sectional view of the second lens module230at A-A ofFIG.8. When the second lens module230is positioned and mated with the first lens module220, the first optical output224may be provided to the second lens array770. The one or more focusing lenses232combined with the adjacent redirecting device234may provide optical signals to the optical fiber cable240, and more particularly optical signals to the respective optical fibers of the optical fiber cable240.

Referring again toFIG.2, the first optical output224at the interface region between the first lens module220and the second lens module230may have a light energy density that may be relatively lower as compared to light energy density of optical light emerging from the emitting source210. Accordingly, a misalignment tolerance specification at the interface between lens modules may not need to be as stringent as compared to when light energy density at an interface adjoining mediums may be comparatively higher.

Referring again toFIGS.6and7, the peripheral fiber grooves660and proximal fiber grooves790may be dimension with triangular, cylindrical, or other profiles for precisely positioning optical fibers adjacent respective lenses of the second lens array770. The respective optical fibers may then be affixed at an aligned position for receiving the second optical output236. Although the second optical output236may have a light energy density that may be relatively higher than the light energy density of the first optical output224, the optical fibers may be integrally fixed relative to respective lenses of the second lens array770.

In some embodiments, the cross-sectional profile of the peripheral fiber grooves660or the proximal fiber grooves790may be dimensioned to position and align optical fiber ends relative to the respective adjacent lenses of the second lens array770within an alignment tolerance value. For example, as illustrated inFIG.9, the cross-sectional profile of the proximal fiber grooves790may be a triangular or saw-tooth profile.

FIG.10illustrates a plan view of a substrate1000for receiving the first lens module220, in accordance with embodiments of the present disclosure. In some examples, the substrate1000may be a printed circuit board. Other types of substrates1000for supporting embodiments of lens modules disclosed herein may be used.

The substrate1000may include one or an array of emitting sources1010, such as a laser array. The array of emitting sources may be energized and modulated for generating optical signals based on electrical connection traces on or within the substrate1000. For example, the substrate1000may be a printed circuit board.

The substrate1000may include substrate apertures1020positioned to correspond to the configuration of the one or more guiding columns552of the first lens module220. In situations where the one or more guiding columns552are received within the substrate apertures1020, the first lens module220may be positioned such that the respective emitting sources1010are substantially aligned with a corresponding collimating lens220of the first lens module.

In some embodiments, the one or more emitting sources1010may be positioned on the substrate1000generally between substrate apertures1020on opposing sides of the substrate1000. The distance between or among the plurality of emitting sources1010may correspond to the distance between or among: (1) corresponding collimating lenses222of the first lens array550; and/or (2) corresponding focusing lenses232of the second lens array77-.

Referring again toFIG.2, in some embodiments of the present disclosure, one or more emitting sources may emit divergent optical signals and be provided to the series of the first lens module220and the second lens module230. The first lens module220may collimate the received divergent optical signals and provide a first optical output224. The light energy density of the first optical output224may be relatively lower as compared to the light energy density of the optical light emitted by the one or more emitting sources.

The second lens module230may receive the first optical output224(e.g., collimated optical signals), and a combination of one or more focusing lenses232and the adjacent redirecting device234may provide focused optical signals to an end of the optical fiber cable240. In some embodiments, the adjacent redirecting device234may be configured as a “45 degree turning surface” such that the overall incident first optical output224may be redirected substantially 90 degrees from the angle of incidence at the second lens module230for providing optical signal output at the end of the optical fiber cable240. Other magnitudes of optical light redirection may be used based on the physical device requirements.

Further, alignment of the first lens module220relative to the second lens module230may be based on receipt of the one or more guiding protrusions780within the one or more guiding apertures426. Upon receipt of the one or more guiding protrusions a within the one or more guiding apertures426, collimating lenses222of the first lens array550may be in alignment with corresponding focusing lenses232of the second lens array770. Based on one or more features of the optical coupler system described herein, there may be reduced eccentricity among respective optical fibers and corresponding lens components.

The optical signal path from the first lens module220to the second lens module230may include optical signals having parallel optical light having comparatively lower light energy density as compared to the light energy density of emitted optical light from the emitting source. Accordingly, a misalignment tolerance specification associated with the combination of the one or more guiding protrusions780(of the second lens module230) and the guiding apertures426(of the first lens module220) may need not be as stringent as compared to when light energy density at an interface between adjoining mediums may be comparatively higher.

A method of assembling an optical coupler system may be provided.

The first lens module220may be positioned and aligned on a substrate1010(FIG.10). The first lens module220may include one or more guiding columns552(FIG.5). The guiding columns552may be aligned with the substrate apertures1020(FIG.10) for aligning the one or more emitting sources1010(FIG.10) with the first lens array550(FIG.5).

In some embodiments, alignment of the first lens module220on the substrate1010may have a defined direction. For example, the substrate1010may include three or more substrate apertures1020corresponding to three or more guiding columns552, such that the first lens module220may be prevented from being positioned on the substrate1010in an undesired orientation that may be 180 degrees from a desired placement position.

The first lens module220may be positioned at an elevation relative to the substrate1010based on one or more reference planes554(FIG.5). The one or more reference places554of the first lens module220may interface with a surface of the substrate1010and may position the first lens module220such that the respective lenses of the first lens array550are at substantially similar distance to the emitting sources as other lenses of the first lens array550.

In some embodiments, the first lens module220may be affixed to the substrate1010using adhesive to provide a laser collimation module.

In some embodiments, the second lens module230may be integrally affixed to an optical fiber cable240(FIG.8). The optical fiber cable240may include one or more optical fibers received within corresponding peripheral fiber grooves660or proximal grooves790. The respective peripheral fiber grooves660or proximal grooves790may be dimensioned with a cross-sectional profile such that the position of a cross-sectional center of the optical fibers may be aligned with a center position of a corresponding lens of the focusing lenses232.

In some embodiments, the optical fibers of the optical fiber cable240may be affixed to the respective proximal fiber grooves790with refractive index matching adhesive. In some embodiments, portions of the optical fibers of the optical fiber cable240may be affixed to the respective peripheral fiber grooves660with refractive index matching adhesive or other types of adhesives. Other types of adhesives may be used for affixing ends of the optical fibers to the proximal fiber grooves790or the peripheral fiber grooves660.

In some embodiments, the second lens module230may be coupled to the first lens module220when the one or more guiding protrusions780(of the second lens module230) are received within corresponding guiding apertures426(of the first lens module220). In some embodiments, the misalignment tolerance specification may be defined as within 10 μm. It may be appreciated that in some scenarios where the light energy density of the first optical output224may be comparatively high (e.g., being focused optical light), the misalignment tolerance specification may need to be more stringent, and be defined as less than 10 μm.

In some embodiments, the first lens module220and the second lens module230may be adhesively affixed for securing the lens modules. Accordingly, optical light emitted by the emitting source210may be coupled to the optical fiber cable240based on lens configurations that may lessen a misalignment tolerance specification. In some embodiments, injection molding operations may be used for constructing the lens modules.

Although the embodiments have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the scope. Moreover, the scope of the present disclosure is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification.