Method and apparatus for integrated optical fiber sensing with nanometer precision

An optical package suitable for alignment with a conductively coated optical fiber includes a base having an electrode which forms a capacitance with the conductively coated optical fiber. An optical alignment system computes a capacitance measure when the optical fiber is precisely aligned and further after attachment of the fiber to the package causes a misalignment. The capacitance measures at precise alignment and at misalignment allow computation of a displacement amount from the precise alignment in at least one direction. The optical fiber may be adjusted according to the direction and amount provided by the alignment system to reposition the fiber to its precise alignment.

FIELD OF THE INVENTION

The present invention relates generally to fiber-coupled optical assemblies and, more particularly, to an apparatus and method of aligning an optical fiber to an optical device by measuring at least one capacitance formed between a conductively coated optical fiber and an electrode on a fiber mounting member.

BACKGROUND OF THE INVENTION

The importance of achieving highly accurate mutual alignment of individual components in any optical system is well known. The miniature dimensions of components used in modern optical communication systems render such accurate alignment difficult both to achieve and to maintain. For example, one issue of concern in the construction of laser transmitters is that of efficiently coupling the optical output from an optical device such as a laser diode into an optical fiber. To obtain efficient coupling, the fiber end is desirably precisely aligned with the emitting area of the laser. When such alignment is achieved, the fiber is then fixed in place, desirably by a method that enables the precise alignment to be sustained throughout the device lifetime.

Typically, fiber-coupled diode lasers are packaged in metal butterfly packages, which may be gold plated, and the fiber is held in alignment with the laser using one of the epoxy, laser weld, or solder attachment techniques with or without a ferrule. Epoxy attachment is low cost but may have too much thermal expansion for high precision attachments. Furthermore, it may not be reliable over a long period of time due to outgassing and alignment shifts arising from aging and temperature cycling. Laser weld techniques are reliable but use costly ferrulization of the fiber and specially designed mounts or clips to allow weld attachment of the ferrulized fiber. The mounts/clips are expensive, large, and may creep over time. Solder attachment techniques, on the other hand, are reliable and low cost, and have become prevalent in the art. Existing solder attachment techniques however, tend to use an integrated heating mechanism and/or a specially configured platform to isolate the heat used for solder reflow. These thermal management means may be expensive and/or undesirably large.

Typically, precise alignment of the fiber involves aligning the end of the fiber in at least one direction relative to the optical device to provide a maximum energy transfer from the optical device to the fiber. A further optical device such as a photodiode or any light emitting diode may be used to measure an optical power coupled into the optical fiber. The fiber may be precisely aligned in at least one of a vertical and a lateral direction. The fiber may also be adjusted horizontally to minimize a gap distance between the fiber and the optical device. The fiber may be adjusted in vertical and lateral alignment until a maximum power is determined. A predetermined gap distance may be used for horizontal alignment or the gap distance may be adjusted while visually monitoring the distance to avoid direct contact between the fiber and the optical device.

It is difficult, however, to maintain alignment between the optical component and the fiber when the fiber is soldered due to turbulent flows and capillary forces exhibited by the molten solder. It is further difficult to determine the precise direction of misalignment after the fiber has been soldered.

SUMMARY OF THE INVENTION

The present invention is embodied in an optical package base for use with a conductively coated optical fiber disposed above the top surface of the base of the package and having an end aligned with an optical device. The optical package base includes a patterned electrode provided adjacent to the top surface of the optical package base and a fiber mount area on the top surface of the optical package base. The conductively coated optical fiber forms a capacitance with the patterned electrode. An optical alignment system for use with the optical package base includes electrical probes and a capacitance detection circuit for determining the capacitance, the capacitance detection circuit coupled to the electrical probes.

The present invention is further embodied in an optical alignment system for aligning a conductively coated optical fiber within an optical package with an optical device to provide an optimally aligned position of an end of the optical fiber with respect to the optical device. The optical alignment system includes two electrodes provided on the optical package, means for measuring at least two capacitances between the conductively coated optical fiber and the two electrodes respectively, to develop first and second capacitance measures. The present invention further includes means for adjusting the optical fiber until the first capacitance measure and the second capacitance measure have substantially equal values, whereby coarse alignment of the optical fiber at the optimally aligned position is attained.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawing, in which like reference numbers refer to like elements throughout the various figures that comprise the drawing,FIG. 1illustrates an optical package100according to the prior art. Prior art package100includes a substrate102for mounting an optical device104. A fiber mounting member106provides an attachment point for optical fiber108that is attached to fiber mounting member106with coupling element110(e.g. solder). Coupling element110maintains the fiber108in a desired alignment throughout the lifetime of optical package100.

Referring now toFIG. 2, a prior art method of aligning optical fiber108to optical device104is described. In step200, optical fiber108is coarsely aligned with optical device104. In step202, optical device104is activated, providing optical energy into optical fiber108according to an alignment between optical fiber108and optical device104. In step204, a power meter (not shown) is activated and a coupling efficiency between optical fiber108and optical device104is desirably measured by the power meter.

Step206checks the measured coupling efficiency to determine whether or not optical fiber108achieved a substantially desired alignment with optical device104. If not, the optical fiber position is adjusted in step208to optimize the alignment according to the coupling efficiency. Steps206and208may be repeated until a peak coupling position is determined.

After a peak coupling position is determined or if no misalignment is determined, step206leads to step210. In step210, optical fiber108is desirably attached to fiber mounting member106with coupling element110. Step210may introduce a misalignment of the optical fiber in at least one direction.

In step212, the optical device is activated. In step214, a power meter is activated to measure the coupling efficiency indicative of the alignment. Step216checks the measured coupling efficiency to determine the presence of misalignment. If no misalignment was introduced, step216leads to step226, which indicates that the alignment process is complete.

If a misalignment was introduced at step210, step216leads to step218. In step218, the optical device is activated and, in step220, the power meter is activated to measure the coupling efficiency. In step222, a localized heating may be provided to adjust the optical fiber. The localized heating may be provided to coupling element110, to fiber mounting member106or optical fiber108. Localized heating may, for example, soften or anneal the coupling element110to allow optical fiber108to move. Localized heating selectively adjusts the fiber position based on a determined misalignment. Localized heating may move the fiber in a direction towards the peak coupling position.

Step224checks the measured coupling efficiency to determine whether or not optical fiber108is substantially aligned with optical device104according to the peak coupling position. If a misalignment was determined, step224leads to step218. Steps218through224are repeated until an optimal alignment is reached. If no misalignment was introduced or an optimal alignment is determined, step224leads to step226, which indicates that the alignment process is complete.

Although the prior art method is useful for attaching optical fibers in a precise and non-contact method, the method typically requires a realignment of the attached optical fiber. Further realignment may be required, particularly after the initial heating of a coupling element.

Although a power meter may measure a coupling efficiency, it may not provide a measure of an offset direction from the peak coupling position. This offset may occur after the initial heating of a coupling element when the fiber may not be easily moved. The power meter does not provide a direction of misalignment. The direction and amount of misalignment is typically estimated and adjusted during a next reheating process.

The present invention provides a method of monitoring the precise location of the optical fiber during the initial alignment through the coupling element reheating process. An exemplary optical package includes an exemplary fiber mounting member provided with electrodes. A capacitance formed between an optical fiber and the electrodes is used to provide a measure of displacement from an optimal position. The number of electrodes may be increased to provide a precise displacement measure in three dimensions.

Referring now toFIGS. 3aand3b, an exemplary optical package300is described.FIG. 3aillustrates a side view of exemplary optical package300. Exemplary optical package300includes a substrate102for mounting optical device104. Exemplary fiber mounting member302includes a fiber mount area304and an electrode area306. Optical fiber308may be attached to fiber mount area304with a coupling element (e.g. solder, not shown).

Optical fiber308desirably includes a metallization310proximate to electrode area306. Although metallization310is shown to extend to the end of optical fiber308, it is understood that metallization310may be provided to only a segment of optical fiber308proximate to electrode area306. Metallization310may not cover a tip of the optical fiber. Although the invention is described in terms of a metallized optical fiber, it is contemplated that any conductively coated optical fiber may be used wherein at least a portion of the conductive coating forms one plate of a capacitor, as described below.

Metallization312may further be provided to fiber308proximate to fiber mount area304. Although metallization312is shown to extend along the remaining length of optical fiber308, metallization312may be provided to only a segment of optical fiber308proximate to fiber mount area304. A non-conductive region314may or may not be provided to fiber308between fiber mount area304and electrode area306to prevent stray capacitative effects between a coupling element and metallization310after the coupling element is provided to attach fiber308to fiber mount area304.

FIG. 3billustrates an overhead view of fiber mounting member302. Optical fiber308may be centered above fiber mounting member302. Fiber mount area304and electrode area306may be provided, for example, on the top surface of fiber mounting member302.

As described above and illustrated inFIG. 3b, optical fiber308may become misaligned in at least one direction due to the application of a coupling element. Misalignment in a first direction is represented by x-axis arrows. Although not shown inFIG. 3b, optical fiber may become misaligned in a second direction. Misalignment in a second direction is represented by the y-axis arrows illustrated inFIG. 7. Misalignment in a third direction is illustrated inFIG. 3bby the z-axis arrows. The optical fiber may become misaligned in any single one of these directions or any combination thereof.

A coupling element of the exemplary invention may be, for example solder. The solder may be provided to fiber mount area304as a solder preform (not shown). It is contemplated that the coupling element may be made of a number of different materials used for mounting optical fibers, which have desired thermal and mechanical properties. It is noted that the desired thermal and mechanical properties may vary depending on the type of the optical device. Coupling element materials may include metal or glass solder, thermally cured epoxy, ultraviolet (UV) cured epoxy and air-cured epoxy. Exemplary metal solder preforms may desirably be formed of any solder alloy which has desired thermal and mechanical properties, such as lead tin solder, gold-based solder, indium-based solder, gallium-based solder, bismuth-based solder, cadmium-based solder or lead-free solder.

It is contemplated that optical device104may include any device or surface from which an optical signal may radiate or receive an optical signal, such as a photodiode, a single mode semiconductor laser, a multi-mode semiconductor laser, an optical mirror, a second optical fiber, a semiconductor optical amplifier, an optical concentrator, and a light-emitting diode.

Fiber mount area304may be a metallization layer on the top surface of fiber mounting member302, as shown inFIG. 3b, to aid in the attachment of the optical fiber to optical package300. When metal solder is used as the coupling element, the metallization layer may include at least one of gold, silver, aluminum, copper, titanium, tungsten or nickel. Electrodes provided in electrode area306may include at least one of gold, silver, aluminum copper, titanium, tungsten or nickel.

The optical fiber may be one of wedge-lensed, ball, conical and flat-cleaved single mode or multi-mode fiber. As described below, the optical fiber desirably includes metallization310proximate to electrode area306to provide a capacitance between the optical fiber and at least one electrode in electrode area306.

Although metallization312is shown on fiber308proximate to the fiber attachment area304, the optical fiber may be non-metallized in this region and attached with glass solder. A bare glass fiber region within fiber mount area304may be attached with metallic solder, with slip between the fiber and solder being desirably minimized by the use of an adhesive, for example, an optical epoxy having low outgassing, low coefficient of thermal expansion and low movement during cure or thermal excursions.

Referring now toFIGS. 3cand3d, an exemplary fiber gripper318that may be used with an exemplary optical package is described. A metallized optical fiber316may be provided to exemplary fiber mounting member302as described above. Fiber gripper318may include a fiber support320and a clamp322to secure optical fiber316within fiber support320. Fiber support320desirably functions as an electrode for coupling to metallized optical fiber316.

Optical fiber316may be attached to fiber mount area304with a coupling element110(e.g. solder) as described above. The metallization of optical fiber316may extend from a region proximate to electrode area306to exemplary fiber gripper318. The metallization may further extend to a tip of the optical fiber316. It is understood that the metallization may be any conductive coating as described above.

FIG. 3dillustrates a cross section of fiber gripper318along cutting plane A-A′. Optical fiber316may be supported by a groove provided to fiber support320. Clamp322may be placed on top of optical fiber316such that a force applied by clamp322and the groove of fiber support320secures the optical fiber316in place.

Fiber support320may be manufactured from any conductive material or conductive material may be provided on a portion fiber support320to act as an electrode. Exemplary fiber gripper318desirably measures a capacitance between optical fiber316and at least on electrode on electrode area306as described below. Fiber support320may further include a contact (not shown) for connection to a capacitance measurement circuit (not shown). It is further understood that clamp322may be similarly provided with electrode material.

Referring now toFIG. 4, an alternate embodiment of an exemplary optical package is described. Exemplary optical package400includes a substrate402and a fiber mounting member404. Optical device104is mounted on fiber mounting member404. Fiber mounting member404further includes fiber mount area406and electrode area408. Optical fiber308may be attached to fiber mount area406as described above. Fiber mount area406and electrode area408are provided on fiber mounting member404in a similar formation as described above and illustrated inFIG. 3b. Optical fiber308includes metallization310proximate to electrode area408and may be further metallized312proximate to fiber mount are406. Fiber308may include a non-metallized region314between metallizations310and312as described above.

Referring now toFIG. 5, an arrangement of at least one electrode on an exemplary fiber mounting member is described. Exemplary fiber mounting member302of exemplary optical package300may include two electrodes502and504provided adjacent to a top surface of fiber mounting member302. It is understood that electrodes may be similarly provided to exemplary fiber mounting member404in electrode area408. Electrodes502and504are desirably triangular shaped and disposed adjacent to each other. Exemplary electrodes502and504are disposed such that a minimum stray capacitance effect is provided between each electrode. A fiber mount area304is provided for attaching optical fiber308to fiber mounting member302. Optical fiber308is desirably metallized along the length of optical fiber at least in a vicinity of electrodes502and504.

Electrodes502and504are illustrated as triangular shaped to provide a linearly varying capacitance between each electrode and metallized optical fiber308when an optical fiber is moved in the first direction. It is contemplated that electrodes502and504may be of any shape provided a measurable variation in capacitance along the first direction may be determined. Electrodes502and504may further includes contacts506disposed on each of electrodes502and504for providing connection of the electrodes to a further apparatus (not shown).

It is contemplated that mounting member302may consist of a single electrode502if only displacement in a single direction is desired. A capacitance between metallization310and electrode502may be used to determine a displacement in a single direction, namely the second direction. Electrode502may further give an indication of displacement in the first direction. A single electrode however, may not provide a precise calculation of misalignment in the first direction.

As described above, a capacitance is desirably formed between metallized optical fiber308and each of electrodes502and504. The cylindrical shape of the fiber provides an insensitivity of the capacitance measurement to fiber rotation. An optical fiber position in the first direction may be measured by taking the difference between the two capacitances. An optical fiber position in the second direction may be measured by taking the sum of the two capacitances.

Peak coupling position first and second direction capacitances may thus be determined prior to a misalignment by a coupling element. A displacement in the first direction and the second direction may be determined by computing the change in first direction and second direction position from the peak coupling position measured before the application of the coupling element. A misalignment in a first and second direction may thus be precisely determined.

Referring now toFIG. 6, an arrangement of three electrodes on an exemplary fiber mounting member302of exemplary optical device300is described. It is understood that electrodes may be similarly provided to exemplary fiber mounting member404in electrode area408. Electrodes502and504are triangular shaped electrodes with contacts506provided as described above. A third electrode602is provided adjacent to a top surface of fiber mounting member302. Electrodes502,504and602are desirably disposed such that a minimum stray capacitance effect is provided between each electrode. A contact506may be further provided to electrode602to allow a connection with a further apparatus (not shown).

Optical fiber308′ is provided metallization310on a portion of fiber308′ proximate to electrodes502,504and602. Optical fiber308′ is similar to optical fiber308′ except that non-metallized region314′ may be a different length to provide a variable capacitance across electrode602, as described below.

First and second capacitances formed between each of electrodes502and504and metallized optical fiber308′ are described above for optical fiber308. A third capacitance may be formed between electrode602and optical fiber308′. Metallization310forms a capacitance that is a function of an amount of metallization area provided to electrode602. It is desirable that a portion of non-metallized region314′ be provided over electrode602during the precise alignment of optical fiber308′ with optical device104to allow a variation in the third capacitance. For example, as optical fiber308′ is moved in the third direction, the metallization area in parallel with electrode602is varied, causing a change in the capacitance. Providing a third electrode may thus provide a measure of fiber position along the third direction.

Referring now toFIG. 7, an exemplary optical alignment system for providing alignment in up to two dimensions using an exemplary optical package is described. The exemplary optical alignment system desirably includes capacitance detection circuit706coupled to electrical probes702. Capacitance detection circuit706is further coupled to position monitoring circuit708.

The exemplary optical alignment system is desirably connected to exemplary optical package300having a fiber mounting member302provided with fiber mount area304and electrode area306as described above. It is understood that the exemplary optical alignment system may be similarly coupled to exemplary optical package400or with any optical package comprising electrodes for measuring a capacitance between the electrodes and the metallized optical fiber.

The exemplary optical alignment system is desirably coupled to exemplary optical package300prior to an alignment of the optical fiber. InFIG. 7, electrode area306may include two electrodes arranged as illustrated inFIG. 5and described above. Electrical probes702may be directly coupled to electrodes502and504illustrated inFIG. 5. Alternatively, electrical probes702may be coupled to contacts provided on each of electrodes502and504. A further contact704may be provided to metallized optical fiber308and coupled to a third electrical probe702. Alternatively, metallized optical fiber316may be used with exemplary fiber gripper318. Fiber gripper318may be coupled to the third electrical probe702. It is understood that the system may provide an alignment in a single direction by using a single electrode502as described above.

Capacitance detection circuit706may be any of a number of well-known circuits for detecting a capacitance between metallized fiber308and each of electrodes502and504. Capacitance detection circuit706is coupled to position monitoring circuit708. Position monitoring circuit708desirably stores the capacitance values measured at the peak coupling position. When the coupling element is heated and cooled, the fiber may be displaced, thus causing the capacitance values to change. Position monitoring circuit708desirably determines a displacement from the optimal alignment in the first direction and may also determine displacement in the second direction according to the capacitance provided by capacitance detection circuit706as described above. The exemplary optical alignment system may thus provide a means for monitoring the optical fiber position in up to two dimensions throughout the alignment process.

An optical fiber alignment to a laser diode is typically less than approximately 2 μm for a multi-mode fiber and typically less than approximately 0.2 μm for single mode fiber in order to obtain a commercially viable coupling efficiency. The inventors have determined that the capacitances measured according to an exemplary embodiment are typically on the order of 10−15F and that the present invention provides a misalignment resolution of about a nanometer order.

Exemplary optical package300may alternatively include feedthrough connections710within mounting member302to connect electrodes502and504to contacts714, respectively, on optical package base712. The optical package may thus be directly connected through contacts714to an exemplary optical alignment system. A third feedthrough710and contact714may be provided for a third electrode602. Alternatively, a single feedthrough710and contact714may be used if alignment in a single direction is desired. It is understood that feedthrough710and contacts714as described above may be provided on an optical package base of exemplary optical package400.

Referring now toFIG. 8, an alternate exemplary optical alignment system for providing an alignment in three dimensions using an exemplary optical package is described. The alternate exemplary optical alignment system desirably includes capacitance detection circuit706′ coupled to electrical probes702. Capacitance detection circuit706′ is further coupled to position monitoring circuit708′.

The alternate exemplary optical alignment system may be coupled to exemplary optical package300. It is understood that the alternate exemplary optical alignment system may be coupled with optical package400or any optical package with electrodes provided for measuring a capacitance between electrodes and a metallized optical fiber.

As described above, the alternate exemplary optical alignment system is desirably coupled to exemplary optical package300prior to an alignment procedure of optical fiber308′ to optical device104. A third electrical probe702may be directly coupled to a third electrode602on fiber mounting member302, illustrated inFIG. 6. Alternatively, electrical probe702may be coupled to a contact506provided on electrode602. Electrodes502and504are desirably coupled as described above. It is understood that metallized optical fiber316may be used with exemplary fiber gripper318as described above.

Capacitance detection circuit706′ may be the same as the circuit706discussed above except that it detects a capacitance between metallized fiber308′ and each of electrodes502,504and602. Capacitance detection circuit706′ is coupled to position monitoring circuit708′. Position monitoring circuit708′ is the same as position monitoring circuit708′ except that it also determines a displacement from the optimal alignment in the third direction as described above. The alternate exemplary optical alignment system may thus provide a means for monitoring the optical fiber position in three dimensions throughout the alignment process.

Referring now toFIG. 9, an exemplary method of aligning an optical fiber to an optical device is described. In step900, electrical probes of an exemplary optical alignment system are coupled to electrodes provided on a fiber mounting member of an exemplary optical device as described above. In step902, the optical fiber may be aligned to the optical output port by a coarse alignment procedure or a fine alignment procedure described below. In step904, a capacitance between at least one electrode and a metallized optical fiber is measured as described above to provide a peak coupling position capacitance.

In step906, a solder preform may be placed over the optical fiber at a fiber attachment point. It is understood that the capacitance may also be measured, step904after step906. It is contemplated that step906may be performed between steps900and902.

In step908, the coupling element may be heated through a solder preform to attach an optical fiber to a fiber mount area. The turbulent flow and capillary forces of the coupling element and its subsequent solidification may cause a misalignment of the optical fiber in at least one direction.

In step910, at least one capacitance is desirably measured. In step912, a first and second direction displacement are computed according to the measured capacitance of step910and the measured capacitance of step904. In alternate step914, a further third direction displacement is computed. It is understood that steps912and914may be combined into a single step or that only a single direction displacement may be computed according to a desired direction.

Step916checks the displacements computed in step912against a predetermined threshold to determine the presence of misalignment and the direction of misalignment if more than one displacement direction is measured. If no misalignment is introduced, step916leads to step928, which indicates that the alignment process is complete.

If the attached fiber is not properly aligned, step916leads to step918. In step918, localized heating is provided to adjust the optical fiber. The at least one direction displacement computed in step914may be used to provide localized heating in at least one direction opposing the at least one displacement direction to move the fiber back to the precisely aligned position of step902. Localized heating may be provided to the optical fiber, to the coupling element or to the fiber mount area and may be a laser heating or a resistive heating. Localized heating may cause the coupling element to be in a plastic state or a fluid state. The localized heating, however, may not provide a complete alignment.

Alternatively, a biasing force may be applied to the optical fiber according to the at least one direction displacement computed in step914. The biasing force may be applied in at least one opposing direction to the at least one displacement direction with an appropriate force to move the fiber according to the displacement. The fiber, fiber mount area or coupling element may then be heated to heat the coupling element into a plastic or fluid state. The biasing force may move the fiber back to the precisely aligned position of step902. The biasing force, however, may not provide a complete alignment.

In step920, at least one capacitance is measured. In step922, a first and second direction displacement are computed according to the measured capacitance of step920and the measured capacitance of step906. In alternate step924, a further third direction displacement is computed. It is understood that steps922and924may be combined into a single step or that only a single direction displacement may be computed according to a desired direction.

Step926checks the displacements computed in step922against a predetermined threshold to determine the presence of misalignment and the direction of misalignment if more than one displacement direction is measured. If no misalignment is introduced, step926leads to step928, which indicates that the alignment process is complete.

If misalignment is present, steps918through926are repeated until the displacement is within the predetermined threshold. When the displacement is within the predetermined threshold, step926leads to step928, which indicates that the alignment process is complete.

Methods for aligning an optical fiber to an optical device, step902, are described inFIGS. 10aand10b. Referring now toFIG. 10a, an exemplary method of coarse alignment of an optical fiber to an optical device is described. In step1000, two capacitances are desirably measured, such as a capacitance between metallized optical fiber308and each of electrodes502and504as described above. Coarse alignment thus may provide a method of determining alignment in the first direction.

Step1002checks if the two capacitances measured in step1000are substantially equal to each other. If the capacitances are substantially equal, step1002leads to step1006, which indicates that the coarse alignment process is complete.

If the capacitances are not substantially equal, step1002leads to step1004. In step1004, the fiber is desirably adjusted to optimize the alignment in the first direction. Steps1002and1004are repeated until the capacitances are substantially equal. When the capacitances are substantially equal, step1002leads to step1006, which indicates that the coarse alignment process is complete.

Referring now toFIG. 10b, a fine alignment method is described. In step1008, an optical component within the optical device is activated. In step1010, a power meter is activated. It is understood that the order of steps1008and1010may be reversed or that they may be combined into a single step.

Step1012checks a coupling efficiency into the optical fiber. A coupling efficiency into the fiber from the activated optical device of step1008is measured by the power meter in step1010. If the fiber is appropriately aligned, a substantial amount of energy from the optical device will be coupled to the fiber, thus providing a high coupling efficiency. If the coupling efficiency is determined to a desired level, step1012leads to step1016, which indicates that the fine alignment process is complete.

If the coupling efficiency not within a desired level, step1012leads to step1014. In step1014, the optical fiber is adjusted in a first and second direction to optimize the alignment to the optical device. Steps1012and1014are repeated until the coupling efficiency is within a desired level. When the coupling efficiency is within a desired level, step1012leads to step1016, which indicates that the fine alignment process is complete.

It is contemplated that either the coarse alignment process or the fine alignment process may performed for step902. It is further contemplated that the course and fine alignment process may be combined into one process for step902, to optimally align the optical fiber to the optical device.