WO2016085473A1

WO2016085473A1 - Light redirecting test fixture

Info

Publication number: WO2016085473A1
Application number: PCT/US2014/067379
Authority: WO
Inventors: Sagi Varghese MATHAI; Christopher WOODY; Jason H CULLER; Paul K ROSENBERG; Wayne V SORIN; Michael Renne Ty Tan; Georgios Panotopoulos
Original assignee: Hewlett Packard Enterprise Development Lp
Priority date: 2014-11-25
Filing date: 2014-11-25
Publication date: 2016-06-02

Abstract

In the examples provided herein, an apparatus has a part with a first reflective surface and a second reflective surface. The apparatus also has alignment features coupled to the part to align the part to a substrate upon which an optical source, a detector, and an integrated circuit are coupled. When the part is aligned to the substrate via the alignment features, the part is positioned to enable: 1) some light emitted by the optical source to be reflected from the first reflective surface; 2) some light reflected from the first reflective surface to be reflected from the second reflective surface; and 3) some light reflected from the second reflective surface to impinge on the detector.

Description

LIGHT REDIRECTING TEST FIXTURE

BACKGROUND

[0001] Optoelectronic devices, such as laser sources and photodetectors, are often co-packaged with application-specific integrated circuits (ASIC) on a single substrate. Each of the optoelectronic devices on the substrate should undergo functional testing to verify optical performance after assembly on the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] The accompanying drawings illustrate various examples of the principles described below. The examples and drawings are illustrative rather than limiting.

[0003] FIG, 1 depicts a cross-section of an example test fixture aligned with sources and detectors attached to a substrate.

[0004] FIGS. 2A, 2B, and 2C depict cross-sections of example solid test fixtures.

[0005] FIGS. 3A and 3B depict cross-sections of example prism-shaped test fixtures.

[0006] FIGS. 4A and 4B depict cross-sections of example thin test fixtures.

[0007] FIGS. 5A-5D depict cross-sections of example test fixtures with additional optical elements.

[0008] FIG. 6 depicts a cross-section of an example test fixture with wavelength-selective optical filters.

[0009] FIG. 7 depicts a flow diagram illustrating an example process of testing a single optical source and detector using a test fixture.

1 [0010] FIG. 8 depicts a flow diagram illustrating an example process of simultaneously testing multiple optical sources and detectors using a test fixture.

[0011] FIG. 9 depicts a flow diagram illustrating an example process of manufacturing a test fixture.

DETAILED DESCRIPTION

[0012] When an array of optical sources and an array of detectors are co- packaged with an integrated circuit (IC) on the same substrate, having a simple method for testing the functionality of fee co-packaged module can be beneficial.

[0013] Example test fixtures are presented below that redirect or loop back optical beams emitted by the array of optical sources to the array of detectors on the same substrate to allow functional testing of the IC in communication with each of the optical sources and detectors after assembly. Simultaneously, the test fixtures can perform the function of protecting the optoelectronics until optical connectors are attached to the module, in one configuration, the test fixture is a part that has a first reflective surface and a second reflective surface in addition to a first set of alignment features coupled to the part to align the part to a substrate upon which a first optical source, a first detector, and an integrated circuit (IC) are coupled. When the part is aligned to the substrate via the first set of alignment features, the part can be positioned to enable: 1} at least some light emitted by the first optical source to be reflected from the first reflective surface; 2) at least some light reflected from the first reflective surface to be reflected from the second reflective surface; and 3) at least some light reflected from the second reflective surface to impinge on the first detector.

[0014] FIG. 1 depicts a substrate 120 to which one or more multiple optical sources 131 and detectors 141 can be coupled. The substrate 120 can be any type of material, such as silicon, glass, ceramic, or an organic material. The optical sources 131 can be any type of optical source, such as a vertical-cavity surface- emitting laser, and the optical sources can be coupled to the substrate, for example, as an array 130. The detectors 141 can be any type of optical detector that is responsive at the wavelengths emitted by the optical sources 131, such as a PIN diode, and the detectors 141 can be coupled to the substrate, for example, as an array 140. A cross-section of the arrays 130, 140 are shown in the example of FIG. 1. In some implementations, tine array 130 of optical sources 131 and/or the array 140 of detectors 141 can be solder-attached to the substrate through flip chip pads 125.

[0015] Each optical source 131 has a unique corresponding detector 141. The light emitted by each particular optical source 131 can have a peak wavelength, and the corresponding detector 141 can detect light at that peak wavelength. As shown in the example of FEG. 1, the optical sources 131 can emit light 135 in a general direction away from the substrate 120, and the detectors can be positioned to receive light generally directed toward the substrate 120.

[0016] In an example implementation of the co-packaged optical sources 131 and detectors 141, the light emitted by the optical sources 131 carries data and can be coupled into optical fibers for transmission over a distance before being received at a group of detectors at a destination location, which may or may not be the detectors 141 on the same substrate 120 as the optical sources 131. At the receiver location, there can be a unique detector corresponding to each optical source 131 to receive the transmitted data. To test the optical sources 131 and detectors 141 assembled on a given substrate 120, the optical fibers and any intermediate optics and/or electronics are not used. The light emitted from the optical sources 131 can be looped back by a test fixture 110 to the corresponding detectors 141 on the same substrate 120, as will be described below. Thus, the optical sources 131 and detectors 141 on the substrate 120 can be used together to functionally test these components.

[0017] The example test fixture 110 shown in FIG. 1 has a first surface 112 and a second surface 114. The surfaces 112, 114 are at least partially reflective at the peak wavelengths of light emitted by the optical sources 131. In some configurations, when light 136 is emitted by the optical sources 131 approximately perpendicularly to the substrate 120, the test fixture 110 is aligned with the optical sources 131 and detectors 141 coupled to the substrate 120, and the first surface 112 and the second surface 114 of the test fixture 110 are angled at approximately 90 degrees to each other, the light 136 emitted by the optical sources 131 can be reflected and redirected by the first surface 112 toward the second surface 114, and the second surface 114 can reflect and redirect the light 145 toward the detectors 141. Thus, the test fixture 110 can loop back or redirect light emitted by the optical sources 131 to a corresponding detector 141. With the use of the test fixture 110, the performance of both the optical sources 131 and detectors 141 can be tested.

[0018] To accurately reflect and redirect light from each of the optical sources 131 to its corresponding detector 141, the test fixture 110 may be aligned to the optical sources 131 and detectors 141 attached to the substrate 120. The test fixture 110 can be aligned through the use of optical sockets 121, 122 mounted on the substrate 120 that are precisely aligned to the optical sources 131 and detectors 141. The optical sockets 121, 122 can have locating holes to receive posts or pins 118, 119 coupled to the test fixture 110, as shown in the example of FIG. 1. Alternatively, posts or pins can be positioned on the substrate 120, and the optical sockets with locating holes can be coupled to the test fixture 110, or one each of a pin and socket can be coupled to the test fixture 110 and the substrate 120. Pins and holes are merely examples of alignment structures that can be used. Any other type of alignment structure can be used to align the test fixture 110 to the optical sources 131 and detectors 141 coupled to the substrate 120. Alternatively, flie test fixture 110 can be vision-aligned to the optical sources 131 and detectors 141 attached to the substrate 120. In this case, the test fixture is not provisioned with mechanical alignment features to mate with complementary alignment features in the optical socket. The test fixture is provisioned with vision alignment fiducials to enable vision alignment to the optical sources 131, detectors 141, and substrate 120. [0019] FIGS. 2A-2C depict cross-sections of example solid test fixtures 200A, 2Q0B, 200C that can each have two surfaces for reflecting light impinging on the surfaces from a location external to the test fixture. For example, in FIG. 2A, at least some light emitted by a first optical source 131 impinges on the first reflective surface 212 from outside the test fixture, and at least some light reflected from the first reflective surface 212 impinges on file second reflective surface 214 from outside the test fixture. Light impinges on the first reflective surface 212, 222, 252 and the second reflective surface 214, 224, 254 of the test fixture 200A. 200B, 200C from a location external to the test fixture,

[0020] Example test fixture 200A shown in FIG. 2A has two surfaces 212, 214 that are at least partially reflective at the wavelengths of light emitted by the optical sources 131. In some implementations, the surfaces 212 and 214 can meet at a comer 216. However, as shown in the example test fixture 200B of FIG. 2B, the test fixture 200B can be formed so that the two reflective surfaces 222, 224 have at least one intermediate surface 216 in between. The length of intermediate surface 216 should be sufficiently short so as not to clip the light emitted by the light source positioned closest to the array of detectors 140. In fact, any configuration of test fixtures as described herein can have one or more intermediate surfaces between the reflective surfaces of the test fixture.

[0021] FIG. 2C shows an example test fixture 200C having a main body 250 with reflective surfaces 252, 254. Surface 252 can have a coating 262 that can modify, that is, either increase or decrease, the reflectivity of the surface 252. For example, if the test fixture 200C is made from a metallic material that has an inherently high surface reflectivity, the coating 262 may be used to lower the reflectivity of the surface 252 to prevent the light redirected toward the detector from saturating the detector. Alternatively, if the reflectivity of the surface 252 is not inherently sufficiently high, for example, if the test fixture were made with a plastic material, the coating 262 may be a high reflectivity coating that increases the amount of light reflected from the surface 252. The surface 254 can be coated in addition to or instead of surface 262. Thus, at least one of the first reflective surface 252 and the second reflective surface 254 can have a coating 262 that modifies the reflectivity of the coated surface.

[0022] Further, as shown in the example of FIG. 2C, an arm 262 having apertures 264 can be coupled to the main body 250 of the test fixture. The apertures 264 can be positioned to eliminate crosstalk between light originating from different ones of the sources in the array of optical sources 130 prior to reaching the array of detectors 140. That is, light emitted by a particular optical source 131 may be redirected to arrive at a detector not corresponding to or intended to detect light emitted by that particular optical source 131, for example, due to stray reflections or diffraction. Thus, the apertures 264 can prevent light from optical sources 131 other than the one corresponding to a specific detector from reaching that detector. In some implementations, if the arm 262 is attached to the main body 250, it may be easier to coat surface 252 on the other half of the main body 250 rather than surface 254 because surface 252 can be more readily accessed. Alternatively, arm 262 can be attached to the main body 250 after surface 252 and/or 254 are coated.

[0023] FIGS. 3A and 3B depict cross-sections of example prism-shaped test fixtures 300A, 30GB. The prism-shaped test fixtures 300A, 300S are solid pieces of material that can be at least partially transparent at the wavelengths of light emitted by the optical sources 131, such as plastic, glass, or semiconductor material.

[0024] At least some light emitted by the array of optical sources 130 can enter the test fixtures 300A, 300B through a base surface 316 of the test fixtures to impinge on a first reflective surface 312 from inside the test fixture. Then at least some light reflected by the first reflective surface 312 can impinge on a second reflective surface 314 from inside the test fixture. Finally, at least some light reflected by the second reflective surface 314 can exit the test fixture through the base surface 316 toward the array of detectors 140. The base surface 316 may be coated with an anthreflection coating 317 to reduce reflections from the base surface 316. |0G25| Example test fixture 300B shown in FIG. 3B is similar to the example test fixture 300A, except a portion of the base surface 316 has an absorptive coating 332 that blocks light at tie wavelengths emitted by the optical sources 131, and the absorptive coating 332 has apertures 344 that can allow light to be transmitted through the base surface 316. Thus, the apertures 344 can eliminate stray light or crosstalk between light originating from different ones of the sources in the array of optical sources 130 prior to reaching the array of detectors 140.

[0026] In contrast with the test fixtures 200A, 200B, 200C as shown in FIGS. 2A, 2B, and 2C and described above, light can impinge on the first reflective surface 312 and second reflective surface 314 of tie test fixtures 300A, 300B from a location internal to tie test fixture.

[0027] FIGS. 4A and 4B depict cross-sections of example thin test fixtures 400A, 400B where light emitted by the optical sources 131 can impinge on the reflective surfaces 412, 414 from a location external to the test fixture, similar to the test fixtures shown in FIGS. 2A, 2B, and 2C. The example test fixture 400A shown in FIG.4A can be created by folding a piece of metal or shaping a piece of plastic or other material and adding alignment features (not shown). The example test fixture 4G0B shown in FIG, 4B has an additional arm 422 with a series of apertures 424 that can be attached to the main frame 420 of the test fixture 400B. Alternatively, the arm 422 can be integrated as a single piece with file main frame 420. As with tie apertures 264 in FIG. 2C and apertures 344 in FIG. 3B described above, apertures 424 can eliminate stray light or crosstalk between light originating from different ones of tie sources in the array of optical sources 130 prior to reaching the array of detectors 140.

[0028] FIGS. 5A-5D depict cross-sections of example test fixtures 500A, 5008, 5Q0C, 500D with additional optical elements. In the example of FIG. 5A, the solid test fixture 500A can have two reflective surfaces 512/514, and incorporated into and/or coupled to one or pofh of the reflective surfaces Si 2, 514 can be a plurality of optical elements 518. The plurality of optical elements 518 may include at least one of the following: mirrors* difrracttve elements, and refractive elements, such as tenses. The optical elements can, for example, collimate light beams emitted by the array of optical sources 130.

[0029] In the example of FIG. 5B, the thin test fixture 5008 has two reflective surfaces 522, 524, and incorporated into and/or coupled to one or both of the reflective surfaces 522, 524 are one or more optical elements 528, similar to optical elements 518. In the example of FIG, 5C, the prism-shaped test fixture 50GC can have two reflective surfaces 532, 534 and a base surface 540 through which light emitted by the optical sources 131 can enter and exit the test fixture 500C. incorporated into and/or coupled to the base surface 540 can be one or more optical elements 542, similar to optical elements 518. in the example of FIG. 5D, the prism- shaped test fixture 500D has two reflective surfaces 552, 554 and a base surface 560 through which light emitted by the optical sources 131 enter the test fixture 500D. Incorporated into and/or coupled to one or both of the reflective surfaces 552, 554 are one or more optical elements 556, similar to optical elements 518.

[0030] FIG. 6 depicts a cross-section of an example test fixture 110 with wavelength selective optical filters 638, 648, where the test fixture 110 is aligned to a substrate 120 that has an optical source array 130 and a detector array 140 coupled to it. At least some of the optical sources 131 in the optical source array 130 can emit light at different peak wavelengths. To verify that the order in which the optical sources 131 have been assembled on the substrate 120 is correct, wavelength selective optical filters 638, 648 can be used that are tuned to the peak wavelengths of the corresponding optical source 131. That is, each of the wavelength selective optical filters 638, 648 can pass light emitted from one of the optical sources and can block light from other optical sources emitting at different wavelengths.

[0031] For example, if each of the optical sources positioned in a first row of optical sources 131 (shown in FIG. 8) emits at the same peak wavelength A; each of the optical sources in a second row of optical sources (not shown) adjacent to the first row of optical sources in the optical source array 130 emit at a peak wavelength B different from wavelength A; and each of the optical sources in a third row of optical sources (not shown) adjacent to the second row of optical sources in the optical source array 130 emit at yet a third peak wavelength C that is different from wavelengths A and B, the wavelength selective optical filters 638, 648 can be tuned to specific peak wavelengths A, B, and C to allow only the appropriate wavelengths to pass. That is, the filters 638, 648 corresponding to the first row of optical sources can pass wavelength A and block wavelengths B and C; the filters corresponding to the second row of optical sources can pass wavelength B and clock wavelengths A and C; and the filters corresponding to the third row of optical sources can pass wavelength C and block wavelengths A and B.

[0032] Then if an optical source in the first row is turned on but the corresponding detector does not receive any light, it may be determined that the order of the optical sources assembled in the optical source array is incorrect, or the optical source may not be functioning correctly.

[0033] ^ln some implementations, the test fixture can also be used to test and bin the co-packaged modules by applying controlled optical losses in the path of the light emitted by the optical sources. The known applied optical losses can simulate actual losses that the light emitted by the optical sources may experience. Optical losses can be applied, for example, by using a known low reflective coating applied to the reflective surfaces 112, 114; by roughening the surface of the reflective surfaces 112, 114 to correspond to a known optical loss; using lossy materials that provide a known optica! loss to manufacture the test fixture; increasing the optical path in the test fixture to allow the light from the optical sources to diverge before reaching the photodetectors; adding a section of lossy material at the entrance and/or exit of the test fixture; placing ah aperture before the photodetectors; and adding a specific amount of mfmr&4 attenuating dye to a molded transrnissive test fixture (for example, as shown in FIG. 3A), where the test fixture is molded to produce a range of desired attenuations, such as 0.1 dB, 0.5dB, 1.OdB. [0034] Then eo-packaged modules that have a lower sensitivity can fee used for applications that have lower losses, such as direct point-to-point optical interconnections. And co-packaged modules that have a higher sensitivity can be used for applications that have higher losses, such as optical interconnections with several intermediate optical connectors. FIG. 7 depicts a flow diagram illustrating an example process 700 of testing a single optical source and detector using a test fixture. At block 705, a first optical source is turned on. The optical source can be tested in different modes. For example, the optical source can be turned on without modulating the output, and a DC measurement can be made at the corresponding detector. In this case, if there is a signal at the corresponding detector, it is a confirmation that both tine optical source and the detector are both functioning. If no signal is received at the detector, and a current-voltage measurement confirms that the detector is operative, then either the optical source is not functional, or the optical source has been mis-positioned in the optical source array and wavelength selective optical filters prevent the light from reaching the detector.

[0035] Alternatively or additionally, the optical source can be tested by operating the optical source as a high speed modulated source. Then a bit error rate measurement or other measurement can be performed on the signal received at the detector to verify that the optical source and detector are functional

[0036] Next, at block 710, light emitted by the first optical source is redirected using a test fixture, for example, the test fixture described in FIG. 1. The test fixture has a first reflective surface, a second reflective surface, and alignment features that align the test fixture to a substrate on which the first optical source and a first detector are coupled, and at least some light emitted by the first optical source is reflected by the first reflective surface and subsequently reflected by the second reflective surface before arriving at the first detector.

[0037] Then at block 715, the performance of the first optical source and the first detector are verified based upon an output of the first detector. The output will depend upon the mode that the optica! source is operated in when It is turned on, for example, DC mode or high speed modulation mode.

[0038] FIG. 8 depicts a flow diagram illustrating an example process 800 of simultaneously testing multiple optical sources and detectors using a test fixture, where the optica! sources and detectors are co-packaged with an IC on the same substrate. At block 805, a first optica! source and an additional optical source are turned on_* As discussed above, the first optical source and the additional optical source can be operated in any mode and even in different modes.

[0039] Then at block 810, the light emitted by the first optical source and the additional optical source is redirected using a test fixture, for example, the test fixture described in FIG.6. The test fixture has a first reflective surface, a second reflective surface, and alignment features that align the test fixture to the substrate on which the first optical source, tie additional optical source, a first detector, and an additional detector are coupled. At least some light emitted by the first optica! source and the additional optical source are reflected by the first reflective surface and subsequently reflected by the second reflective surface before arriving at the first detector and the additional detector, respectively.

[0040] Next, at block 815, light emitted by the first optical source is filtered using a first wavelength selective optical filter that permits light emitted by the first optica! source to pass and blocks light from the additional optical source. And at block 820, light emitted by the additional optica! source is filtered using an additional! wavelength selective optica! filter that permits light emitted by the additional optica! source to pass and blocks light from the first optica! source. One or more wavelength selective optica! filters can be used for each corresponding pair of optical source and detector.

[0041] Then at block 825, the performance of the first optical source and the first detector are verified based upon an output of the first detector, and the performance of the additional optica! source and the additional detector are verified based upon an output of the additional detector. [0042] And at Nock 830, the substrate with the first and additional optical sources and the first and additional detectors is binned based on the performance verification of the first optical source and the additional optical source, where the performance verification includes determining optical intensities detected at the first photodetector and the additional photodetector and a bit error rate measured by the IC.

[0043] As can be seen in FIGS. 1 and 6, In addition to redirecting the light emitted by the optical sources 131 to the detectors 141 on the substrate 120 for testing, the test fixture 110 can also protect the optica! sources 131 and detectors 141 Thus, the test fixture 110 can be placed on the substrate 120 after assembly of the optical sources 131 and detectors 120 on the substrate 120, left in place on the substrate 120 for testing, and remain in place after testing until the optical sources 131 and/or the detectors 141 are ready to be coupled to a connector, such as a fiber pigtail or optical ferrule. Once the test fixture 110 is removed, it can either be discarded or recycled for use as a test fixture for other assembled substrates.

[0044] FIG. 9 depicts a flow diagram illustrating an example process 900 of manufacturing a test fixture component having a first reflective surface, a second reflective surface, diffractive or refractive elements, and alignment features to align the component to a substrate. At block 905, the first reflective surface of the component is created. And at block 910, the second reflective surface of the component is created. The diffractive or refractive elements are created and positioned on at least one of the first reflective surface and the second reflective surface. At block 915, the alignment features of the component are created, where the alignment features include at least one of a pin and a hole. The reflective surfaces, diffractive or refractive elements, and alignment features of the component are created by using a technique selected from a group including: plastic injection molding, extrusion, metal stamping, diamond turning, fly cutting, sawing, laser ablation, for example, of a V-groove into a metal piece or other material to create the thin test fixture configuration, and sheet metal folding where a thin piece of sheet metal is folded to create the thin test fixture configuration and subsequently alignment features are stamped into the part or punched through the opposite surface. The steps in blocks 905, 910, 915 can be performed simultaneously, for example, with the technique of injection molding, or sequentially, for example, with the technique of diamond turning.

[0045] Not ail of the steps, or features presented above are used In each implementation of the presented techniques. Further, steps In processes 700, 800* and 900 can be performed in a different order than presented.

Claims

CLAIMS What is claimed is:

1. An apparatus comprising:

a part having a first reflective surface and a second reflective surface; and

a first set of alignment features coupled to the part to align the part to a substrate upon which a first optical source, a first detector, and an integrated circuit (iC) are coupled,

wherein when the part is aligned to the substrate via the first set of alignment features, the part is positioned to enable: 1) some light emitted by tie first optical source to be reflected from the first reflective surface; 2) some light reflected from the first reflective surface to be reflected from the second reflective surface; and 3) some light reflected from the second reflective surface to impinge on the first detector.

2. The apparatus of claim 1, wherein the some light emitted by the first optical source impinge on the first reflective surface from outside the part, and the some light reflected from the first reflective surface impinge on the second reflective surface from outside the part.

3_r The apparatus of claim 2, wherein at least one of the first reflective surface and the second reflective surface has a coating to modify reflectivity of the coated surface.

4. The apparatus of claim 2, further comprising an arm coupled to the part, wherein the first optical soiree Is part of an array of optica! sources on the substrate,

wherein the first detector is part of an array of detectors on the substrate,

wherein each of the optical sources has a corresponding detector for detecting light emitted by the corresponding optical source, wherein when the part is aligned to the substrate via the first set of alignment features, the part is positioned to further enable at least some light emitted by each of the optical sources in the array of optical sources to be reflected from the first reflective surface, and wherein the arm has a plurality of apertures that are positioned to eliminate crosstalk between light originating from different ones of the array of optical sources prior to reaching the array of detectors.

5. The apparatus of claim 2, wherein at least one of the first reflective surface and the second reflective surface have a plurality of diffractive, refractive, or reflective elements.

6. The apparatus of claim 2, further comprising a plurality of wavelength selective filters,

wherein the first optical source Is part of an array of optical sources on the substrate,

wherein the first detector is part of an array of detectors on the substrate,

wherein each of tie optical sources has a corresponding detector for detecting light emitted by the corresponding optical source, wherein when the part is aligned to the substrate via the first set of alignment features, the part is positioned to further enable at least some light emitted by each of the optical sources in file array of optical sources to be reflected from the first reflective surface, and wherein each of the plurality of wavelength selective filters passes light emitted from one of the optical sources and blocks light from the other optical sources, and further wherein at least some of the optical sources emit light at different peak wavelengths.

7. The apparatus of claim 1, wherein the part is at least partially transmissive,

wherein at least some light emitted by the first optical source enters the part through a base surface of the part and impinges on the first reflective surface from inside the part,

wherein at least some light reflected by the first reflective surface impinges on the second reflective surface from inside the part, and

wherein at least some light exits the part through the base surface toward the detectors.

8. The apparatus of claim 7, wherein the base Surface has a coating to reduce reflections.

9. The apparatus of claim 7,

Wherein the first optical source is part of an array of optical sources on the substrate_*

wherein the first detector is part of an array of detectors on the substrate,

wherein each of the optical sources has a corresponding detector for detecting light emitted by the corresponding optical source, wherein when the part is aligned to the substrate via the first set of alignment features, the part is positioned to further enable at least some light emitted by each of the optical sources in file array of optical sources to be reflected from the first reflective surface, wherein a portion of the base surface has a coating to block light, and the coating has a plurality of apertures that allow light to be transmitted through the base surface, wherein the apertures are positioned to eliminate crosstalk between fight originating from different ones of the array of optical sources prior to reaching the array of detectors.

10. The apparatus of claim 7, further comprising a plurality of elements on at least one of the first reflective surface, the second reflective surface, and the base surface, wherein the plurality of elements include at least one of the following: diffractive elements, refractive elements, and mirrors.

11 The apparatus of claim 7, further comprising a plurality of wavelength selective filters*

wherein the first detector is part of an array of detectors on the substrate,

wherein each of the array of optical sources has a corresponding detector for detecting light emitted by the corresponding optical source,

wherein when the part is aligned to the substrate via the first set of alignment features, the part is positioned to further enable at least some light emitted by each of the optical sources in the array of optical sources to be reflected from the first reflective surface, wherein each of the plurality of wavelength selective filters passes light emitted from one of the optical sources and blocks light from the other optical sources, and further wherein each optical source emits light at a different peak wavelength.

12. A method comprising:

turning on a first optica! source;

redirecting light emitted by the first optical source using a test fixture, wherein the test fixture has a first reflective surface, a second reflective surface, and alignment features that align the test fixture to a substrate on which the first optica! source and a first detector is coupled, wherein at least some light emitted by the first optical source are reflected by the first reflective surface and subsequently reflected by the second reflective surface before arriving at the first detector;

verifying performance of the first optical source and the first detector based upon an output of the first detector.

13. The method of claim 12, further comprising:

turning on an additional optical source, wherein the additional optical source and an additional detector are positioned on the substrate; redirecting light emitted by the additional optical source using the test fixture, wherein at least some light emitted by the additional optical source are reflected by the first reflective surface and subsequently reflected by the second reflective surface before arriving at the additional detector;

verifying performance of the additional optical source and trie additional detector based upon an output of the additional detector, wherein the first optical source and the additional optical source are turned on simultaneously or sequentially.

14. The method of claim 13, further comprising: filtering light emitted by the first optical source using a first optical filter that permits light emitted by the first optical source to pass and blocks light from the additional optical source;

filtering light emitted by the additional optical source using an additional optical filter that permits light emitted by the additional optical source to pass and blocks light from the first optical source, wherein the first optical source and the additional optical source emit light at different peak wavelengths; and

binning the substrate with the first and additional optical sources and the first and additional detectors based on the performance verification of the first optical source and the additional optical source, wherein the performance verification includes determining optical intensities detected at the first photodetector and the additional photodetector and a bit error rate measured by an integrated circuit (IC), wherein the IC is co-packaged on the substrate.

15. A method of manufacturing a component having a first reflective surface, a second reflective surface, diffractive, refractive, or reflective elements, and alignment features to align the component to a substrate, tile method comprising:

creating the first reflective surface- creating the second reflective surface, wherein the diffractive, refractive, or reflective elements are positioned on at least one of the first reflective surface and the second reflective surface;

creating the alignment features, wherein the alignment features include at least one of a pin and a hole;

wherein the first reflective surface, the second reflective surface, the diffractive, refractive, or reflective elements, and $he alignment features of the component are created by using at least one technique selected from a group comprising: injection molding, extrusion, metal stamping, diamond turning, fly Gutting, sawing, laser ablation, and sheet metal folding.