TWI426309B - An optoelectronic package - Google Patents

Description

Photoelectric package and its certification method

The present invention relates to an optoelectronic package structure, and more particularly to an optoelectronic package structure including a passive optical component, wherein the passive optical component is used to control optical back reflection, thereby improving an optoelectronic device mounted in the optoelectronic package. Performance.

Optoelectronic packaging is used in the field of optical fiber communication to install optoelectronic devices. In addition, other optics and electrical components associated with the optoelectronic device can be incorporated into the optoelectronic package. An example of an optoelectronic package is a transistor outline (TO), commonly referred to as a cylindrical package (TO-can). The optoelectronic device installed in the optoelectronic package is a converter for converting the optical data signal into an electrical data signal or converting the electrical data signal into an optical data signal. Examples of optoelectronic devices include side-emitting lasers such as Fabry-Perot lasers, decentralized feedback lasers, and surface-emitting lasers, such as vertical cavity surface-emitting lasers (vertical cavity) Surface emitting lasers; VCSEL) and long-wavelength vertical cavity surface-emitting lasers.

A common problem in optoelectronic packages is optical back reflection (OBR). Optical back reflections can cause interference between optical data signals, a phenomenon commonly referred to as noise. Some types of side-shooting lasers and surface-emitting lasers, such as long-wavelength vertical cavity surface-emitting lasers, are particularly sensitive to optical back reflections.

One method of reducing the noise generated by optical back reflection in an optoelectronic package is to use an optical isolator. The function of the optical isolator is to block the optical back reflection from reaching the optoelectronic device mounted in the optoelectronic package. While the use of optical isolators can help prevent optical back reflections from reaching optoelectronic devices housed in optoelectronic packages, thereby maintaining noise below acceptable standards, optical isolators are expensive to manufacture.

In general, embodiments of the present invention are directed to an optoelectronic package including two or more passive optical components for controlling the amount of optical back reflection that reaches the optoelectronic device disposed within the optoelectronic package. By controlling the optical back reflection in this way, the noise in the optoelectronic package can be controlled accordingly, thereby contributing to the improvement of the performance of the optoelectronic package.

In an embodiment, the optoelectronic package comprises an optoelectronic device, a wave plate, and a linear polarizer. Optoelectronic devices are used to emit optical signals along the optical path. The wave plate is located on the optical path of the photovoltaic device. The linear polarizer is also located on the optical path of the optoelectronic device between the optoelectronic device and the wave plate.

In another embodiment, the long-wavelength vertical cavity surface-emitting laser optoelectronic package comprises a long wavelength (LW) vertical cavity surface-emitting laser (VCSEL), a four A quarter wave plate (QWP) and a linear polarizer. Long-wavelength vertical cavity surface-emitting lasers are used to emit optical signals along the optical path. The emitted optical signal contains a specific polarization. Quarter wave plate is located in long wavelength vertical cavity surface type The laser's light path. The quarter-wave plate contains a fast axis that deviates from the long-wavelength vertical cavity surface-emitting laser beam by a polarization direction of about 45 degrees. The linear polarizer is located between the long-wavelength vertical cavity surface-emitting laser and the quarter-wave plate on the optical path of the long-wavelength vertical cavity surface-emitting laser. The linear polarizer substantially aligns with the polarization direction of the optical signal of the long-wavelength vertical cavity surface-emitting laser emission.

In an embodiment, a method of certification of an optoelectronic package comprises several steps. First, an optoelectronic device is used to generate an optical signal. Then, the optical signal is polarized to the first line polarization state. Next, the polarized optical signal is converted into a circularly polarized light having a phase shift of 90 degrees between the fast axis and the slow axis such that the polarization direction of the fast axis and the polarized optical signal is 45 degrees. Then, the portion of the phase shifted optical signal is reflected back to the optoelectronic device. Furthermore, the reflected partial optical signal is phase-shifted from the circularly polarized state to the second linearly polarized state, and the second linearly polarized state is about 90 degrees from the first linearly polarized state. Then, the reflected portion of the phase-shifted optical signal is polarized to the first line polarization state. Accordingly, the relative noise intensity of the photovoltaic device is measured. The measured relative noise strength is then compared to the relative noise strength specified by the agreement. Finally, if the measured relative noise strength is within the maximum acceptable deviation of the relative noise intensity specified by the agreement, then the optoelectronic package is determined to pass.

The above and other aspects of the embodiments of the present invention will be more apparent from the following description and the appended claims.

As described above, embodiments of the present invention relate to one that includes two or more passive An optoelectronic package of optical components, wherein the passive optical components are used to control the amount of optical back reflections that reach the optoelectronic devices housed within the optoelectronic package. By controlling the optical back reflection in this way, the noise in the optoelectronic package can be controlled accordingly, thereby contributing to the improvement of the performance of the optoelectronic package.

The term "optical package" as used in this specification refers to any package that houses an optoelectronic device. The term "optoelectronic device" as used in this specification refers to an electro-optical or optical-to-electrical converter. The optoelectronic device disclosed in the present specification can be used to transmit or receive a plurality of protocol optical signals of various line rates. For example, the optoelectronic device disclosed in the present specification can be used to process optical signals such as: fiber optic high-speed Ethernet, fiber ultra-high-speed Ethernet, 1x Fibre Channel, 2x Fibre Channel, 4x Fibre Channel, and Synchronous Optical Network (Synchronous Optical) Network; SONET) Optical Carrier (OC)-3, SONET OC-12, SONET OC-48, SONET OC-192, SONET OC-768, 10x Fibre Channel or 10 billion bit Ethernet. Similarly, the optoelectronic device disclosed in the present specification can operate at the following nominal rates: 155 Mb/s, 200 Mb/s, 622 Mb/s, 1.25 Gb/s, 2.125 Gb/s, 2.67 Gb/s, 4.25 Gb/s, 10.3. Gb/s, 10.5 Gb/s, 10.7 Gb/s or 11.1 Gb/s.

I. Examples of optoelectronic packages

Referring now to "FIG. 1", an example of an optoelectronic package 100 is shown. The optoelectronic package 100 includes a housing 102. The outer casing 102 is a sealed, crystal-type outer casing, commonly referred to as a cylindrical cylindrical package. As such, the housing 102 can be incorporated into a transmitter optical subassembly (TOSA) (not shown).

The housing 102 includes a cylindrical package header 104 containing electrical components 105 and an optoelectronic device 106. One or more electrical components are used to receive the electrical data signal and transmit the electrical data signal through the headstock 104 to the optoelectronic device 106. One or more electrical components are also used to receive current and transmit this current through the headstock 104 to provide power to the optoelectronic device 106. One or more electrical components are further used to receive the control signal and transmit the control signal through the header 104 to the optoelectronic device 106. In this example, the optoelectronic device 106 is a long wavelength vertical cavity surface-emitting laser. As used in this specification, the term "long-wavelength vertical cavity" surface-emitting laser ray refers to a wavelength of light data transmitted between approximately 1200 nm and 1900 nm, or even longer wavelengths. The scope of protection of the present invention is not limited to long-wavelength vertical cavity surface-emitting lasers, and other types of optoelectronic devices can be used in embodiments of the present invention.

In the embodiment, the photovoltaic device 106 is a long-wavelength vertical cavity surface-emitting laser grown on a gallium arsenide substrate using molecular beam epitaxy (MBE). The active region of the long-wavelength vertical cavity surface-emitting laser contains three 55-Å (Å) gallium indium arsenide (InGaAsN) quantum wells separated by a gallium arsenide spacer layer. The active region of the long-wavelength vertical cavity surface-emitting laser is sandwiched between the p-type gallium arsenide conductive layer and the n-type gallium arsenide conductive layer. The p-type gallium arsenide conductive layer is above the active region and the n-type gallium arsenide conductive layer is below the active region. The p-type and n-type gallium arsenide conductive layers serve as internal cavity contact points for long-wavelength vertical cavity surface-emitting lasers. The p-type and n-type gallium arsenide conductive layers are sandwiched at the bottom of 37 pairs of undoped aluminum gallium arsenide/arsenide gallium dispersive Bragg reflectors (DBR). And between the top 8 pairs of dielectric dispersed Bragg reflectors.

The optoelectronic device 106 acts as an electro-optical converter. Here, the optoelectronic device 106 receives the electrical data signal received by the electrical component as an input, and transmits the corresponding optical data signal 108 as an output. The optoelectronic device 106 is further configured to emit an optical data signal 108 along the optical path, wherein the optical path is indicated by an arrow shown in FIG. In addition, optoelectronic device 106 emits an optical data signal 108 having a known polarization.

Optoelectronic device 106 is used to emit optical data signal 108 of one of a plurality of wavelengths, depending on the needs of the particular application. For example, optoelectronic device 106 can emit optical data signal 108 having a wavelength of 1310 nm or 1550 nm. In addition, optoelectronic device 106 can operate at a variety of data rates. For example, optoelectronic device 106 can operate at a nominal rate of about 4.25 Gb/s or about 10 Gb/s, or even higher.

Please refer to FIG. 1 again. The optoelectronic package 100 further includes a lens 110, a linear polarizer 112, a wave plate 114 and a window 116. Each component is located on the optical path of the optical data signal 108. The functions of these components will be described in turn below.

In this example, the lens 110 is an aspherical lens, but is not limited thereto, and other lenses may be used, including a spherical lens or a hemispherical lens. When the optical data signal 108 passes through the lens 110, the lens 110 is used to focus the optical data signal 108. In another embodiment, lens 110 can be combined with one or more additional lenses to further focus or otherwise process optical data signal 108. In one embodiment, the lens 110 can be removed and the optical data signal 108 can be transmitted from the optoelectronic device 106 to the linear polarizer 112 without first passing through the lens.

When the optical data signal 108 passes through the linear polarizer 112, the linear polarizer 112 is used to polarize the optical data signal 108. In the embodiment, the linear polarizer 112 can be substantially aligned with the known polarization state of the optoelectronic device 106, so the attenuation of the optical data signal 108 through the linear polarizer 112 is relatively small.

When the optical data signal 108 passes through the wave plate 114, the wave plate 114 is used to phase shift the optical data signal 108. Typically, the wave plate is an optical device that changes the polarization state of the light waves passing through the wave plate. In the embodiment, the wave plate 114 is a quarter wave plate. When the optical data signal 108 passes through the quarter wave plate, it is used to phase shift the optical data signal 108 by about 90 degrees. Thus, when the optical data signal 108 passes through the quarter-wave plate, the quarter-wave plate causes the optical data signal 108 to phase shift by a quarter wavelength. In this embodiment, the fast axis of the quarter wave plate is offset from the known polarization state of the optoelectronic device 106 by about 45 degrees. When the optical data signal 108 passes through the quarter wave plate, the optical data signal 108 is converted from a linearly polarized optical data signal into a circularly polarized optical data signal.

Window 116 allows optical data signal 108 to exit sealed enclosure 102. Generally, the window 116 can be made of any light transmitting material that is capable of maintaining the seal of the outer casing 102. In another embodiment, the outer casing 102 is not sealed and the window 116 need not be capable of maintaining a seal or the window 116 can be completely removed.

II. Operation of an embodiment of an optoelectronic package

During operation, the optoelectronic package 100 controls the optical back reflection of the optoelectronic devices that reach the optoelectronic package 100 by simple and inexpensive optical components. In particular, embodiments of optoelectronic package 100 use simple and inexpensive components such as the aforementioned linear polarizer 112 and Wave plate 114, thereby providing relatively less optical back reflection to optoelectronic device 106.

In an embodiment, the wave plate is a quarter wave plate. When the optical back reflection is toward the optoelectronic device 106, any portion of the circularly polarized optical data signal 108 is reflected back, although reflected as optical back reflection, but The circularly polarized optical data signal 108 emitted by the optoelectronic device 106 remains substantially maintained.

In particular, when the optical back reflection passes through the quarter wave plate, the optical back reflection of the circularly polarized light is converted into an optical back reflection of the linearly polarized light, the direction of which is approximately 90 degrees from the initial linear polarization of the optical data signal 108. . When the optical back reflection of the line polarization reaches the line polarizer 112, the line polarizer 112 substantially blocks all optical back reflections. As a result, the amount of optical back reflection that reaches the optoelectronic device 106 is reduced below the extent that is achieved by other means. In this way, the optical back reflection is controlled, and the degree of noise in the optoelectronic package 100 is correspondingly reduced. The reduction in the degree of noise within the optoelectronic package 100 can result in a lower error rate of optical communication between the optoelectronic package 100 and another optical device.

Although the example of the optoelectronic package 100 disclosed in the present specification is provided with a long-wavelength vertical cavity surface-emitting laser, the configuration of the optoelectronic package 100 can also be applied to other optoelectronic packages in which other types of optoelectronic devices are mounted. For example, optoelectronic packages incorporating side-emitting lasers or other types of surface-emitting lasers may benefit from the arrangement of linear polarizers 112 and wave plates 114. Therefore, the scope of protection of the present invention is not limited to an optoelectronic package in which a long-wavelength vertical cavity surface-emitting laser is mounted, and the present invention is not limited to the type, number, or arrangement of components shown in FIG.

III. Examples of experimental devices

In the experimental apparatus disclosed in "Fig. 2", the optoelectronic package 200 is similar to the above-described example of the optoelectronic package 100. The optoelectronic package 200 includes a vertical cavity surface-emitting laser 202 mounted on a high speed test strip. The DC current source 204 is used to drive a vertical cavity surface-emitting laser. A bit error rate tester (BERT) 206 modulates the DC current source 204 through a bias tee 208. The optical signal 210 generated by the vertical cavity surface-emitting laser 202 is coupled to the single mode fiber (SMF) of the angle splitting (angled contact type; Angled Polished/Physical Contact; APC) by the aspherical lens 214. 212. The line polarizer 216 is adjacent to and located on the path of the optical signal 210 emitted by the vertical cavity surface type laser 202. The line polarizer 216 can be disposed and disposed in a polarized state of the optical signal 210. The quarter-wave plate 218 has a fast axis that is about 45 degrees from the polarization of the optical signal 210. In this embodiment, the coupling efficiency (CE) of the single mode fiber 212 is maintained at 3 dB. The single mode fiber 212 passes through the polarizer controller 220 and the attenuator 222 before reaching the mirror 224. The second single mode fiber 226 is branched from the single mode fiber 212. The second single mode fiber 226 can connect the optoelectronic package 200 to an optical metrology device, such as a digital communications analyzer (DCA) 228, an optical spectrum analyzer (OSA) 230, or a power meter. 232. The optical signal is then reflected by the mirror and is directed along the single mode fiber 212 toward the vertical cavity surface. The amount of light that is effectively returned to the optoelectronic package 200 depends on the optical coupling loss of the single mode fiber 212 and the attenuation through other optical paths. In this device, The amount of reflected light entering the optoelectronic package 200 ranges from -7 dB to -60 dB.

IV. Experimental results

"Fig. 3" shows the relative intensity noise (RIN) of the vertical cavity surface-emitting laser in the optoelectronic package 200 at different bias currents under different degrees of optical back reflection. Relative noise strength and optical power noise and average power Related, it can be expressed as: Where P ( t ) is the output power of a time-dependent vertical cavity surface-emitting laser in a given polarization state, and This is the average power of the vertical cavity surface-emitting laser in this polarized state.

In an experiment performed in an optoelectronic package 200, when various amounts of optical back reflection are introduced into the optoelectronic package 200, the long-wavelength vertical cavity surface-emitting laser system has a DC bias current of 6 mA to 10 mA. Provide power. The corresponding relative noise strength in the optoelectronic package is measured and compared to the requirements of the 2x Fibre Channel specification. By reference, the 2x Fibre Channel specification requires a maximum RIN ₁₂ (OMA) of -120 dB/Hz, which corresponds to a maximum relative noise strength specification of -138 dB/Hz under DC bias. The relative noise intensity in the optoelectronic package is measured when the optical back reflection ranges from -7 decibels to -60 decibels through the quarter wave plate and the line polarizer. Even in the worst case measurement, when the optical back reflection is -7 dB, the 2x Fibre Channel specifications also meet the appropriate limits. Please refer to "Figure 3". Figure 300 reveals the results of this experiment.

This experiment confirmed that the photovoltaic device 106 and the linear polarizer 112 shown in "Fig. 1" The arrangement of the waveplates 115 can be effectively used to control the amount of optical back reflection that reaches the optoelectronic device 106. The reduction in optical back reflection can reduce the level of noise in the optoelectronic package 100, thereby improving the performance of the optoelectronic device 106.

IV. Examples of methods for certification of optoelectronic packaging

Referring now to Figure 4, an example of a method 400 for certification of optoelectronic packages is disclosed. The example of method 400 includes a number of steps that can be used to validate or reject an optoelectronic package, such as optoelectronic package 100 or optoelectronic package 200 as disclosed herein.

An example of method 400 includes using an optoelectronic device to generate an optical signal (step 402). For example, the vertical cavity surface-emitting laser 202 of the optoelectronic package 200 can be used to generate the optical signal 210.

The method 400 also includes polarizing the optical signal to a first line polarization state (step 404). For example, the line polarizer 216 can be used to polarize the optical signal 210 to a first line polarization state.

An example of method 400 further includes phase shifting the polarized optical signal by about 90 degrees to produce a circularly polarized state (step 406). For example, the quarter wave plate 218 can be used to phase shift the polarized optical signal by about 90 degrees to transition from the first linear polarization state to the circular polarization state.

An example of method 400 further includes reflecting a portion of the phase shifted optical signal back to the optoelectronic device (step 408). For example, mirror 224 can be used to reflect a portion of the phase shifted optical signal back to the optoelectronic device.

An example of the method 400 further includes phase shifting the reflected partial optical signal to switch from a circularly polarized state to a second linearly polarized state, the second linear polarization state being offset from the first The line polarization state is about 90 degrees (step 410). For example, a quarter wave plate 218 can be used to phase shift the reflected portion of the optical signal 210 to transition from a circularly polarized state to a second linearly polarized state that is about 90 degrees from the first linearly polarized state.

An example of method 400 further includes polarizing the reflected portion of the phase shifted optical signal to a first line polarized state (step 412). For example, the line polarizer 216 can be used to polarize the reflected portion of the phase-shifted optical signal 210 to the first line polarized state. Because the reflected portion of the phase shifted optical signal is about 90 degrees from the first line polarized state, the linear polarizer 216 substantially blocks the reflected portion of all phase shifted optical signals.

An example of method 400 also includes measuring the relative noise intensity of the optoelectronic device (step 414). For example, the relative noise intensity of the vertical cavity surface-emitting laser 202 can be measured.

An example of method 400 also includes comparing the measured relative noise strength to the relative noise strength provided by the agreement (step 416). For example, the relative noise intensity of the measured vertical cavity surface-emitting laser 202 can be compared to the relative noise strength specified by any of the agreements disclosed herein, such as the 2x Fibre Channel protocol.

An example of method 400 further includes determining whether the measured relative noise strength is within an acceptable maximum deviation of the agreed relative noise strength (step 418). If within the acceptable maximum deviation, the example of method 400 proceeds to step 420 to verify that the optoelectronic package is acceptable. If not within the acceptable maximum deviation, the example of method 400 proceeds to step 422 to reject the optoelectronic package. For example, if the measured relative noise intensity of the vertical cavity surface-emitting laser 202 is within the maximum acceptable deviation of the relative noise intensity specified by the 2x fiber channel, it can be determined that the optoelectronic package 200 conforms to 2x. Fibre Channel. On the other hand, if the relative noise intensity of the measured vertical cavity surface-emitting laser 202 is not within the maximum acceptable deviation of the relative noise intensity specified by the 2x fiber channel, the optoelectronic package 200 can be rejected because it does not match 2x Fibre Channel protocol. The maximum acceptable deviation 〞 referred to herein is a preset value, for example, may be specified by a specific agreement or specified by a user.

Although the present invention has been disclosed above in the foregoing embodiments, it is not intended to limit the invention. It is within the scope of the invention to be modified and modified without departing from the spirit and scope of the invention. Please refer to the attached patent application for the scope of protection defined by the present invention.

100‧‧‧Optoelectronic packaging

102‧‧‧Shell

104‧‧‧ head seat

105‧‧‧Electrical components

106‧‧‧Optoelectronic devices

108‧‧‧Light information signal

110‧‧‧ lens

112‧‧‧Line polarizer

114‧‧‧ Wave Plate

116‧‧‧ window

200‧‧‧Optoelectronic packaging

202‧‧‧Vertical cavity surface-emitting laser

204‧‧‧DC current source

206‧‧‧ bit error rate tester

208‧‧‧ bias T-joint

210‧‧‧Optical signal

212‧‧‧ single mode fiber

214‧‧‧Aspherical lens

216‧‧‧Line polarizer

218‧‧‧ quarter wave plate

220‧‧‧ Polarizer controller

222‧‧‧ attenuator

224‧‧‧Mirror

226‧‧‧Second single mode fiber

228‧‧‧Digital Communication Analyzer

230‧‧‧Spectral Analyzer

232‧‧‧Electric power meter

300‧‧‧ Chart

400‧‧‧Qualification method for optoelectronic packaging

Step 402‧‧‧ Use optoelectronic devices to generate optical signals

Step 404‧‧‧Polarized optical signal to the first line polarization state

Step 406‧‧‧ phase shifting the component of the polarized optical signal by approximately 90 degrees to produce a circularly polarized state

Step 408‧‧‧ Reflecting a portion of the phase-shifted optical signal back to the optoelectronic device

Step 410‧‧‧ The component of the reflected portion of the phase-shifted optical signal is from a circularly polarized state to a second-line polarized state, and the second-line polarized state is about 90 degrees away from the first-line polarized state

Step 412‧‧‧Position of the reflected portion of the phase-shifted optical signal to the first line polarization state

Step 414‧‧‧Measure the relative noise intensity of the optoelectronic device

Step 416‧‧‧Compare the relative noise intensity measured and the relative noise intensity specified in a protocol

Step 418‧‧ Is the measured relative noise strength within the maximum acceptable deviation of the relative noise strength specified in the agreement?

Step 420‧‧‧Determining that the optoelectronic package is qualified

Step 422‧‧‧Rejected optoelectronic package

1 is an embodiment of the optoelectronic package of the present invention; FIG. 2 is an embodiment of an experimental apparatus for testing an optoelectronic package; and FIG. 3 is an experiment apparatus using the apparatus shown in FIG. The results produced by the experiment; and Fig. 4 show an embodiment of the method for determining the optoelectronic package of the present invention.

100‧‧‧Optoelectronic packaging

102‧‧‧Shell

104‧‧‧ head seat

105‧‧‧Electrical components

106‧‧‧Optoelectronic devices

108‧‧‧Light information signal

110‧‧‧ lens

112‧‧‧Line polarizer

114‧‧‧ Wave Plate

116‧‧‧ window

Claims (12)

A long-wavelength vertical cavity surface-emitting laser photoelectric package comprising: a long-wavelength vertical cavity surface-emitting laser for emitting an optical signal along a light path; a quarter-wave plate ( a quarter wave plate; QWP), located on the optical path, the quarter wave plate includes a fast axis, about 45 degrees offset from a polarization state of the optical signal; and a linear polarizer located on the long wavelength vertical cavity surface On the optical path between the laser and the quarter-wave plate, the pair of polarizers is located in the polarized state of the optical signal. The optoelectronic package of claim 1, wherein the long-wavelength vertical cavity surface-emitting laser, the line polarizer, and the quarter-wave plate are packaged in a transistor outline (TO) ) for bonding to a Light Emitting Secondary Module (TOSA). The optoelectronic package of claim 1, wherein the long-wavelength vertical cavity surface-emitting laser emits an optical data signal having a wavelength of about 1310 nm or about 1550 nm. The optoelectronic package of claim 1, wherein the long-wavelength vertical cavity surface-emitting laser comprises: an active region comprising three indium arsenide arsenide (InGaAsN) having a thickness of 55 Å (Å) Quantum wells, the indium gallium arsenide (InGaAsN) quantum wells are separated by a gallium arsenide spacer; A p-type gallium arsenide conductive layer is disposed over the active region; and an n-type gallium arsenide conductive layer is located under the active region. The optoelectronic package of claim 1, wherein the long-wavelength vertical cavity surface-emitting laser further comprises: a distributed Bragg reflector (DBR) located in the n-type arsenic. Below the gallium conduction layer; and a top eight-pair dielectric dispersion Bragg reflector located above the n-type gallium arsenide conductive layer. The optoelectronic package of claim 5, wherein the bottom dispersion type Bragg reflector comprises thirty-seven pairs of undoped aluminum gallium arsenide or gallium arsenide. The optoelectronic package of claim 1, wherein the long wavelength vertical cavity surface-emitting laser is compatible with a nominal data rate of 4.25 Gbits per second and 10 Gbits per second. The optoelectronic package of claim 1, wherein the long-wavelength vertical cavity surface-emitting laser is substantially in compliance with 2x when an optical back reflection is greater than about -20 decibels at the quarter-wave plate. Fibre Channel regulations. A method for verifying an optoelectronic package, the method comprising: generating an optical signal using an optoelectronic device; using a linear polarizer to polarize the optical signal to a first linear polarization state; using a quarter wave plate phase shift The component of the polarized optical signal is about 90 degrees to produce a circularly polarized state, wherein the quarter-wave plate includes a fast axis. 45 degrees deviating from a polarization state of the optical signal; reflecting a portion of the phase-shifted optical signal back to the optoelectronic device; using the quarter-wave plate, phase shifting a component of the reflective portion of the optical signal from the circularly polarized state a second line polarization state, the second line polarization state is offset from the first line polarization state by about 90 degrees; polarization is reflected by the phase shifting of the reflected portion of the optical signal to the first line polarization state; measuring the photoelectric device Relative noise strength; comparing the measured relative noise strength with a relative noise intensity as specified by the agreement; and determining if the measured relative noise strength is within the maximum acceptable deviation of the relative noise strength specified in the agreement The optoelectronic package is qualified. The method of claim 9, wherein the step of reflecting a portion of the phase-shifted optical signal back to the optoelectronic device reflects the phase-shifted optical signal from about -7 decibels to about -60 decibels. Return to the optoelectronic device. The method of claim 9, wherein the step of generating an optical signal using an optoelectronic device comprises using a photovoltaic device that supplies a DC bias current between 6 mA and 10 mA to generate a Long wavelength optical signal. The method of claim 9, wherein the comparing the measured relative noise strength with a predetermined relative noise intensity, wherein the relative noise intensity specified by the agreement is a 2x Fibre Channel specification The relative noise intensity specified.