Patent Publication Number: US-2023161098-A1

Title: Pluggable optical modules with blind mate optical connectors

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of co-pending U.S. patent application Ser. No. 17/446,013, filed Aug. 26, 2021, which claims benefit of U.S. provisional patent application Ser. No. 63/199,825, filed Jan. 27, 2021. The aforementioned related patent application is herein incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     Embodiments presented in this disclosure generally relate to co-packaged optics (CPO) applications, and more specifically, to pluggable optical modules for CPO applications. 
     BACKGROUND 
     Co-packaged optics (CPO) applications have the potential for lower power and lower cost implementations, but tighter integration of the optics tends to create some operational challenges. For traditional CPO applications, users tend to have reduced flexibility for optical interfaces after the installation of the network equipment. Lasers, commonly used with CPO applications, may also present thermal challenges when co-located with other optical hardware. Further, the lasers can pose a reliability risk, which tends to compound within increasing numbers of lasers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above-recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate typical embodiments and are therefore not to be considered limiting; other equally effective embodiments are contemplated. 
         FIG.  1    is a network device supporting multiple pluggable optical modules, according to one or more embodiments. 
         FIG.  2    illustrates coupling a pluggable optical module with a network device, according to one or more embodiments. 
         FIG.  3    illustrates coupling two pluggable optical modules in a stacked configuration with a network device, according to one or more embodiments. 
         FIGS.  4 A and  4 B  provide views of a pluggable optical module configured as a laser module unit with multiple remote laser sources, according to one or more embodiments. 
         FIGS.  5 A and  5 B  provide views of a pluggable optical module configured as an optical conditioning unit with a fanout device, according to one or more embodiments. 
         FIG.  6    provides a view of a pluggable optical module configured as a hybrid laser module and optical conditioning unit, according to one or more embodiments. 
         FIGS.  7 A and  7 B  provide views of a network device with multiple laser module units, according to one or more embodiments. 
         FIGS.  8 A- 8 D  illustrate a sequence of assembling and coupling a host-side connector assembly with connectors of a pluggable optical module, according to one or more embodiments. 
         FIG.  9    illustrates a connector assembly having an opening through an endface, according to one or more embodiments. 
         FIG.  10    illustrates a connector assembly having an I-shaped endface, according to one or more embodiments. 
     
    
    
     To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one embodiment may be beneficially used in other embodiments without specific recitation. 
     DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Overview 
     One embodiment presented in this disclosure is a pluggable optical device comprising a housing, a printed circuit board (PCB) within the housing, and one or more blind mate optical connectors attached to the PCB along a first end of the PCB. The pluggable optical device further comprises one or more electrical contacts of the PCB near the first end, one or more external optical connectors arranged near a second end of the PCB opposite the first end, and one or more optical components attached to the PCB and included in optical paths extending between the one or more external optical connectors and the one or more blind mate optical connectors. 
     Another embodiment presented in this disclosure is an optical system comprising a printed circuit board (PCB), a photonic integrated circuit (IC) attached to the PCB, and a cage attached to the PCB along a first end of the PCB. The cage is configured to receive a pluggable optical device. The optical system further comprises a connector assembly configured to, when the pluggable optical device is received in the cage, couple with a plurality of blind mate optical connectors arranged along a second end of a pluggable optical device. One or more optical components of the pluggable optical device are coupled with the photonic IC. When the pluggable optical device is received in the cage, the connector assembly is further configured to couple with one or more electrical contacts arranged near the second end. 
     EXAMPLE EMBODIMENTS 
     Embodiments discussed herein includes a pluggable optical device (also referred to as a “pluggable optical module”) comprising a housing, a printed circuit board (PCB) within the housing, one or more blind mate optical connectors attached to the PCB along a first end of the PCB, and one or more electrical contacts of the PCB near the first end. The pluggable optical device further comprises one or more external optical connectors attached to the PCB along a second end of the PCB opposite the first end, and one or more optical components attached to the PCB. The one or more optical components are included in optical paths extending between the one or more external optical connectors and the one or more blind mate optical connectors. 
     The blind mate optical connector(s) may be attached to a top side of the PCB, and the electrical contact(s) may be arranged at a bottom side of the PCB. In some embodiments, the electrical contact(s) comprise an edge connector configured to couple with elastically-biased contact(s) of a host device. As the pluggable optical device is plugged into the host device, the mechanical housing (or cage) of the host device, in conjunction with the housing of the pluggable optical module, ensures that the optical connector(s) are suitably engaged as the electrical contact(s) are also engaged. The electrical contact(s) may communicate power and/or signals between the host device and the pluggable optical device. For example, the electrical contact(s) may be USB-style or other suitable configuration to deliver power and management signals to the pluggable optical device. 
     The pluggable optical device may be configured to operate as a laser module unit (including one or more remote laser sources), an optical conditioning unit that provides one or more optical functions to optical signals carried through the pluggable optical device on optical fibers, or a hybrid laser module and optical conditioning unit. Beneficially, using remote laser source(s) in the pluggable optical device addresses heating concerns by spacing the remote laser source(s) away from other optical hardware of the CPO, and allows the remote laser source(s) to be easily replaced to address reliability concerns. 
     The electrical connector(s) and optical connector(s) of the pluggable optical device are arranged to enable high system density, e.g., stacking of multiple pluggable optical modules. The high system density supports existing system integration techniques for power and cooling. The pluggable optical device and host device may use any suitable dimensioning, whether standardized dimensioning such as Quad Small Form-Factor Pluggable Double Density (QSFP-DD), Octal Small Form-Factor Pluggable (OSFP), or proprietary dimensioning. 
     A conventional pluggable form factor device used as a laser source for a co-packaged optics-based system may include electrical connectors on the host side of the PCB, and an external optical connector arranged at the faceplate. The conventional pluggable optical device provides optical energy (e.g., power and/or signals) to the host device through the external optical connector, a patchcord, and another connector at the faceplate. Beneficially, by including the blind mate optical connector(s), the pluggable optical device preserves faceplate area for other functions (additional pluggable optical devices, air intakes, etc.) and tends to have lower optical losses overall. 
       FIG.  1    is a network device  100  supporting multiple pluggable optical modules, according to one or more embodiments. The network device  100  may be a CPO device providing any suitable networking functionality, such as switching or routing. 
     The network device  100  comprises a housing  105  within which components of the network device  100  are housed. The housing  105  may be formed of any suitable material(s) and may have any suitable dimensioning. In some embodiments, the housing  105  has a standardized dimensioning such that the network device  100  is rack-mountable. 
     In some embodiments, the housing  105  comprises a system PCB (or host PCB) that includes electronic components and optical components, and that couples with pluggable optical devices that are plugged into openings  120 - 1 ,  120 - 2 , . . . ,  120 - 16 , which are defined by a faceplate  110  of the housing  105 . The openings  120 - 1 ,  120 - 2 , . . . ,  120 - 16  are arranged as pairs  115 - 1 ,  115 - 2 , . . . ,  115 - 8  in a “stacked” configuration (as shown, a vertical arrangement of the respective openings  120 - 1 ,  120 - 2 , . . . ,  120 - 16 ). In this way, the network device  100  may support a stacked configuration of pluggable optical devices with each pair  115 - 1 ,  115 - 2 , . . . ,  115 - 8   
     The faceplate  110  further defines multiple air intakes  125 ,  130  that support air flow through the housing  105  to remove heat from the various components of the network device  100 . In some embodiments, the network device  100  further comprises one or more fans that draw air into the housing  105  through the air intakes  125 ,  130 . The air intakes  125 ,  130  may have any suitable dimensioning and arrangement. For example, the air intake  125  between pairs  115 - 1 ,  115 - 2  has a first sizing, and the air intake between  115 - 4 ,  115 - 5  has a second sizing greater than the first sizing. As shown, the air intake  130  has a central position on the faceplate  110  while the air intakes  125  are between adjacent pairs  115 - 1 ,  115 - 2 , . . . ,  115 - 8  away from the central position. 
       FIG.  2    illustrates coupling a pluggable optical module with a network device, according to one or more embodiments. The features illustrated in diagram  200  may be used in conjunction with other embodiments, e.g., using the network device  100  of  FIG.  1   . 
     In the diagram  200 , a pluggable optical module  205  is inserted into an opening  120  of the network device (also referred to as a “host device”). The openings  120 - 1 ,  120 - 2 , . . . ,  120 - 16  of  FIG.  1    may be considered instances of the opening  120 . The pluggable optical module  205  comprises a housing  210 , a PCB  215  within the housing  210 , one or more blind mate optical connectors  220  attached to the PCB  215  along a first end of the PCB  215  (e.g., a lead edge of the PCB  215  as inserted into the opening  120 ), and one or more electrical contacts  225  attached to the PCB  215  near the first end. In some embodiments, the network device provides electrical power and/or signals to the pluggable optical module  205  using the one or more electrical contacts  225 . 
     The housing  210  may have any suitable dimensioning for being received into the opening  120 . Although not shown, the network device may include a cage or other structure that is dimensioned to receive the pluggable optical module  205  therein. In some embodiments, the housing  210  is contoured to slide into and out of the network device through the opening  120 . The housing  210  may have a standardized dimensioning (e.g., to comply with QSFP-DD), or may have a proprietary dimensioning. 
     The one or more blind mate optical connectors  220  and the one or more electrical contacts  225  may have any suitable dimensioning. Some non-limiting examples of the blind mate optical connector(s)  220  include Mechanical Transfer (MT), Multiple-Fiber Push-On/Pull-Off (MPO, MTP), SN, and so forth. In some embodiments, each of the blind mate optical connector(s)  220  comprises one or more ferrules that couple with a plurality of optical fibers. In some embodiments, the one or more electrical contacts  225  comprise an edge connector having one or more conductive traces. 
     In some embodiments, the one or more blind mate optical connectors  220  are attached to a top side of the PCB  215 , and the one or more electrical contacts  225  are attached to a bottom side of the PCB  215 . In some embodiments, the one or more electrical contacts  225  couple with electrical contacts  245  on the host device side, which in some cases may be elastically biased. 
     The host device comprises a host PCB  240 , one or more connectors  230  attached to the host PCB  240 , and one or more optical fibers  235  coupled with the connector  230 . In some embodiments, each of the one or more connectors  230  is formed of a single component. In other embodiments, each of the one or more connectors  230  may be a connector assembly formed of multiple components. The one or more connectors  230  are configured to receive the one or more blind mate optical connectors  220 , which aligns one or more optical components of the pluggable optical module  205  into a coupled configuration with the one or more optical fibers  235 . In some embodiments, the one or more connectors  230  retain the one or more blind mate optical connectors  220  in the coupled configuration. 
     In the coupled configuration, the electrical contacts  245  are coupled with the one or more electrical contacts  225 . In some embodiments, the compliance of the electrical contacts  245  (when elastically biased) accommodates the alignment of the one or more connectors  230  with the one or more blind mate optical connectors  220 . As shown, the electrical contacts  245  are attached to the host PCB  240 . In alternate implementations, the electrical contacts  245  are attached to the one or more connectors  230 . The connector  230  may include electrical contacts on a bottom side of the connector  230  that couple with corresponding electrical contacts on a top side of the host PCB  240  when the connector  230  is attached to the host PCB  240 . 
       FIG.  3    illustrates coupling two pluggable optical modules in a stacked configuration with a network device, according to one or more embodiments. The features illustrated in diagram  300  may be used in conjunction with other embodiments, e.g., using the network device  100  of  FIG.  1   . 
     In the diagram  300 , a first pluggable optical module  205 - 1  is inserted into an upper opening  120 - 1  of the pair  115 - 1 , and a second pluggable optical module  205 - 2  is inserted into a lower opening  120 - 2 . The network device comprises a cage  305  that is attached to the host PCB  240 , and that defines the upper opening  120 - 1  and the lower opening  120 - 2 . 
     One or more additional components of the host device may be attached to the cage  305 . In some embodiments, a connector assembly  310  is attached to the cage  305 , and comprises a first connector  230 - 1  aligned with the upper opening  120 - 1 , and a second connector  230 - 2  aligned with the lower opening  120 - 2 . Each of the connectors  230 - 1 ,  230 - 2  represents one example of the connector  230  of  FIG.  2   , and in some cases may be similarly configured to each other. The connectors  230 - 1 ,  230 - 2  may be connected into the connector assembly  310  using any suitable techniques. In alternate embodiments, the first connector  230 - 1  and the second connector  230 - 2  are separate from each other. 
     A heat sink  315  is attached to a top of the cage  305  and extends partly into the interior volume of the cage  305 . The heat sink  315  thermally couples with the first pluggable optical module  205 - 1 , e.g., by contacting the top of the cage of the first pluggable optical module  205 - 1  when the first pluggable optical module  205 - 1  is inserted into the upper opening  120 - 1 . A heat sink  320  is attached to the cage  305  and extends partly into the interior volume of the cage  305 . The heat sink  320  thermally couples with the second pluggable optical module  205 - 2 , e.g., by contacting the top of the cage of the second pluggable optical module  205 - 2  when the second pluggable optical module  205 - 2  is inserted into the lower opening  120 - 2 . In some embodiments, the heat sink  315  is configured as a top heat sink, and the heat sink  320  is configured as an integrated riding heat sink. 
       FIGS.  4 A and  4 B  provide views of a pluggable optical module  405  configured as a laser module unit with multiple laser sources, according to one or more embodiments. More specifically, diagram  400  of  FIG.  4 A  provides a top view of the pluggable optical module  405 , and diagram  445  of  FIG.  4 B  provides an end view of blind mate optical connectors  420 - 1 , . . . ,  420 - 4  of the pluggable optical module  405 . The features illustrated in diagrams  400 ,  445  may be used in conjunction with other embodiments. For example, the pluggable optical module  405  represents one possible implementation of the pluggable optical module  205  of  FIG.  2    and may be inserted into, e.g., the host devices illustrated in  FIGS.  2  and  3   . 
     In the diagram  400 , the pluggable optical module  405  comprises a housing  410 , and a PCB  415  arranged in the housing  410  and attached to the housing  410 . The pluggable optical module  405  further comprises a plurality of blind mate optical connectors  420 - 1 , . . . ,  420 - 4  attached to a top side of the PCB  415  along a first end of the PCB  415 , and a plurality of electrical contacts  425 - 1 , . . . ,  425 - 5  arranged at a bottom side of the PCB  415  near the first end. Although four (4) blind mate optical connectors  420 - 1 , . . . ,  420 - 4  and five (5) electrical contacts  425 - 1 , . . . ,  425 - 5  are shown, other numbers and placements of these are also contemplated. For example, the plurality of electrical contacts  425 - 1 , . . . ,  425 - 5  may be arranged at a top side of the PCB  415 . 
     The pluggable optical module  405  further comprises a plurality of laser sources  430 - 1 ,  430 - 2 ,  430 - 3 ,  430 - 4  that receive electrical power provided by the host device via one or more of the electrical contacts  425 - 1 , . . . ,  425 - 5 . The laser sources  430 - 1 ,  430 - 2 ,  430 - 3 ,  430 - 4  generate and deliver optical energy to the host device via the blind mate optical connectors  420 - 1 , . . . ,  420 - 4 . As shown, the laser source  430 - 1  includes multiple laser channels coupled to the blind mate optical connector  420 - 1  via multiple optical fibers, the laser source  430 - 2  is coupled to the blind mate optical connector  420 - 2  via multiple optical fibers, and so forth. 
     The pluggable optical module  405  further comprises a plurality of electronic components that are attached to the PCB  415  and that receive the electrical power provided by the host device. As shown, the plurality of electronic components comprise a microcontroller  440  and three (3) DC-DC converters  435 - 1 ,  435 - 2 ,  435 - 3 , although other arrangements of electronic components are also contemplated. In some embodiments, the DC-DC converters  435 - 1 ,  435 - 2 ,  435 - 3  convert a voltage level of the received electrical power to voltage levels suitable for the laser sources  430 - 1 ,  430 - 2 ,  430 - 3 ,  430 - 4 . In some embodiments, the microcontroller  440  receives input signals from the host device via one or more of the electrical contacts  425 - 1 , . . . ,  425 - 4 , and generates control signals to operate the DC-DC converters  435 - 1 ,  435 - 2 ,  435 - 3  and/or the laser sources  430 - 1 ,  430 - 2 ,  430 - 3 ,  430 - 4 . 
     The plurality of laser sources  430 - 1 ,  430 - 2 ,  430 - 3 ,  430 - 4  and the plurality of electronic components may have any suitable arrangement on the PCB  415 . As shown, the electronic components are generally arranged along a centerline of the PCB  415 , and the laser sources  430 - 1 ,  430 - 2 ,  430 - 3 ,  430 - 4  are arranged laterally outward from the electronic components. Beneficially, the arrangement may support routing of the various optical fibers through the pluggable optical module  405 . 
     The small form factor of the pluggable optical module  405  accommodates known system integration and thermal cooling techniques. As mentioned above, the pluggable optical module  405  is configured to operate as a laser module unit. The pluggable nature of the pluggable optical module  405  beneficially permits a degraded or failed laser source  430 - 1 ,  430 - 2 ,  430 - 3 ,  430 - 4  to be easily replaced (e.g., hot-swapped). Routing the optical energy from the laser sources  430 - 1 ,  430 - 2 ,  430 - 3 ,  430 - 4  to the blind mate optical connectors  420 - 1 , . . . ,  420 - 4  ensures that the pluggable optical module  405  is eye-safe to a user of the system. The blind mate optical connectors  420 - 1 , . . . ,  420 - 4  of the pluggable optical module  405  also provide lower optical losses, when compared with routing optical energy to the host device through external patchcords. 
       FIGS.  5 A and  5 B  provide views of a pluggable optical module  505  configured as an optical conditioning unit with a fanout device  535 , according to one or more embodiments. More specifically, diagram  500  of  FIG.  5 A  provides a top view of the pluggable optical module  505 , and diagram  555  of  FIG.  5 B  provides an end view of external optical connectors  515 - 1 ,  515 - 2  of the pluggable optical module  505 . The features illustrated in diagrams  500 ,  555  may be used in conjunction with other embodiments. For example, the pluggable optical module  505  represents one possible implementation of the pluggable optical module  205  of  FIG.  2    and may be inserted into, e.g., the host devices illustrated in  FIGS.  2  and  3   . 
     In the diagram  500 , the pluggable optical module  505  comprises a housing  510 , and a PCB  520  arranged in the housing  510  and attached to the housing  510 . The pluggable optical module  505  further comprises the blind mate optical connectors  420 - 1 , . . . ,  420 - 4  attached to a top side of the PCB  520  along a first end of the PCB  520 , and a plurality of electrical contacts  425 - 1 , . . . ,  425 - 5  arranged at a bottom side of the PCB  520  near the first end. 
     The pluggable optical module  505  further comprises two (2) external optical connectors  515 - 1 ,  515 - 2  arranged near a second end of the PCB  520  opposite the first end. As shown, the external optical connectors  515 - 1 ,  515 - 2  extend through the housing  510  and are in a stacked configuration. In alternate implementations, one or more of the external optical connectors  515 - 1 ,  515 - 2  may be attached to the PCB  520  near the second end. The external optical connectors  515 - 1 ,  515 - 2  may have any suitable dimensioning. Some non-limiting examples of the external optical connectors  515 - 1 ,  515 - 2  include Mechanical Transfer (MT), Multiple-Fiber Push-On/Pull-Off (MPO, MTP), SN, and so forth. In some embodiments, each of the external optical connectors  515 - 1 ,  515 - 2  comprises a plurality of ferrules that couple with a plurality of optical fibers. 
     The pluggable optical module  505  further comprises one or more optical components that are attached to the PCB  520  and that are included in optical paths extending between the one or more external optical connectors  515 - 1 ,  515 - 2  and the blind mate optical connectors  420 - 1 , . . . ,  420 - 4 . As shown in the diagram  500 , the one or more optical components comprise a fanout device  535 . 
     Other optical components of the pluggable optical module  505  need not be attached to the PCB  520 . For example, a plurality of single mode optical fibers  540  couples the fanout device  535  with a first connector  515 - 1  of the one or more external optical connectors  515 - 1 ,  515 - 2  and a multicore optical fiber  530  couples the fanout device  535  with a second connector  420 - 4  of the one or more blind mate optical connectors  420 - 1 , . . . ,  420 - 4 . Additionally, one or more single mode optical fibers  525 - 1  extend between the external optical connectors  515 - 1  and the blind mate optical connector  420 - 2 , and one or more single mode optical fibers  525 - 2  extend between the external optical connector  515 - 1  and the blind mate optical connector  420 - 3 . 
     The pluggable optical module  505  further comprises a plurality of electronic components that are attached to the PCB  520  and that receive the electrical power provided by the host device. As shown, the plurality of electronic components comprise a microcontroller  550  and a DC-DC converter  545 , although other arrangements of electronic components are also contemplated. 
     As mentioned above, the pluggable optical module  505  is configured to operate as an optical conditioning unit. While a single fanout device  535  is depicted for simplicity, the pluggable optical module  505  may comprise passive optical components and/or active optical components (i.e., that receive electrical power from the host device via one or more of the electrical contacts  425 - 1 , . . . ,  425 - 5 ) to provide any other suitable optical conditioning functionality. The optical conditioning may be performed on optical signals propagating through the pluggable optical module  505  in any direction (whether the optical signals are input at the external optical connectors  515 - 1 ,  515 - 2  or at the blind mate optical connectors  420 - 1 , . . . ,  420 - 4 ). In some embodiments, the pluggable optical module  505  comprises one or more active optical components, which comprise one or more of an optical amplifier, an optical attenuator, an optical filter, an optical dispersion controller, an optical multiplexer, an optical demultiplexer, an optical switch, and an optical repeater. 
     The small form factor of the pluggable optical module  505  accommodates known system integration and thermal cooling techniques. By including the external optical connectors  515 - 1 ,  515 - 2 , the pluggable optical module  505  effectively permits the faceplate of the host device to be reconfigurable, allowing users to specify optical fiber connectors, pigtails, and so forth. Further, a higher density of the faceplate is made possible by the combination of the electrical contacts  425 - 1 , . . . ,  425 - 5  and the blind mate optical connectors  420 - 1 , . . . ,  420 - 4  at a same end of the pluggable optical module  505 . Further, the pluggable optical module  505  provides a compact and protected optical fiber fanout functionality (or any suitable alternate optical conditioning functionality) that is also field replaceable. 
       FIG.  6    provides a view of a pluggable optical module  605  configured as a hybrid laser module and optical conditioning unit, according to one or more embodiments. More specifically, the diagram  600  provides a top view of the pluggable optical module  605 . The features illustrated in the diagrams  600  may be used in conjunction with other embodiments. For example, the pluggable optical module  605  represents one possible implementation of the pluggable optical module  205  of  FIG.  2    and may be inserted into, e.g., the host devices illustrated in  FIGS.  2  and  3   . 
     In the diagram  600 , the pluggable optical module  605  comprises a housing  610 , and a PCB  615  arranged in the housing  610  and attached to the housing  610 . The pluggable optical module  605  further comprises the blind mate optical connectors  420 - 1 , . . . ,  420 - 4  attached to a top side of the PCB  520  along a first end of the PCB  615 , and a plurality of electrical contacts  425 - 1 , . . . ,  425 - 5  arranged at a bottom side of the PCB  615  near the first end. 
     The pluggable optical module  605  further comprises the plurality of laser sources  430 - 1 ,  430 - 2 ,  430 - 3 ,  430 - 4  that receive electrical power provided by the host device via one or more of the electrical contacts  425 - 1 , . . . ,  425 - 5 . As shown, the laser sources  430 - 1 ,  430 - 2  each include multiple laser channels coupled to the blind mate optical connector  420 - 1  via multiple optical fibers, and the laser sources  430 - 3 ,  430 - 4  each include multiple laser channels coupled to the blind mate optical connector  420 - 2  via multiple optical fibers. 
     The pluggable optical module  405  further comprises a plurality of electronic components that are attached to the PCB  615 : the microcontroller  440  and the DC-DC converters  435 - 1 ,  435 - 2 ,  435 - 3 . 
     The pluggable optical module  605  further comprises two (2) external optical connectors  515 - 1 ,  515 - 2  arranged near a second end of the PCB  615  opposite the first end. Additionally, one or more single mode optical fibers  620  extend between the external optical connectors  515 - 1  and the blind mate optical connector  420 - 3 , and one or more single mode optical fibers  625  extend between the external optical connector  515 - 1  and the blind mate optical connector  420 - 4 . The pluggable optical module  605  may further comprise one or more optical components that are attached to the PCB  615  and that are included in optical paths extending between the one or more external optical connectors  515 - 1 ,  515 - 2  and the blind mate optical connectors  420 - 1 , . . . ,  420 - 4 . The one or more optical components may provide any suitable optical conditioning functionality for the pluggable optical module  605 . 
     Due to its hybrid nature, the pluggable optical module  605  provides the various benefits discussed above with respect to the pluggable optical modules  405 ,  505 . Further, the integration of the laser sources  430 - 1 ,  430 - 2 ,  430 - 3 ,  430 - 4  in the pluggable optical module  605  with the electronic components and/or the optical components providing the optical conditioning functionality permits an even higher density of the faceplate. 
       FIGS.  7 A and  7 B  provide views of a network device  702  with multiple pluggable optical modules  740 - 1 , . . . ,  740 - 8 , according to one or more embodiments. More specifically, diagram  700  of  FIG.  7 A  provides a top view of the network device  702  (showing pluggable optical modules  740 - 1 , . . . ,  740 - 4 ), and diagram  760  of  FIG.  7 B  provides a side view of the network device  702  (showing pluggable optical modules  740 - 4 ,  740 - 8 ). The features illustrated in diagrams  700 ,  760  may be used in conjunction with other embodiments. For example, the network device  702  represents one possible implementation of the host devices illustrated in  FIGS.  2  and  3   . 
     In the diagram  700 , the network device  702  comprises a host PCB  705 , and a substrate  710  arranged on the host PCB  705 . In some embodiments, the substrate  710  comprises a silicon substrate, although other implementations of the substrate  710  are also contemplated. An application-specific integrated circuit (ASIC)  715  (e.g., a host processor) and a plurality of photonic dies  720 - 1 , . . . ,  720 - 4  are arranged on the substrate  710 . A respective electronic die  725  is arranged on each photonic die  720 - 1 , . . . ,  720 - 4 . Each of the ASIC  715 , the plurality of photonic dies  720 - 1 , . . . ,  720 - 4 , and the electronic dies  725  may provide any suitable functionality for processing electrical signals and/or optical signals. 
     A respective fiber array unit (FAU)  730  is arranged on each photonic die  720 - 1 , . . . ,  720 - 4 . The FAUs  730  attach to respective optical fibers  745 - 1 , . . . ,  745 - 4  and position the optical fibers  745 - 1 , . . . ,  745 - 4  to optically couple with optical waveguides or other optical components formed in the respective photonic dies  720 - 1 , . . . ,  720 - 4 . Each of the optical fibers  745 - 1 , . . . ,  745 - 4  may represent a respective one or more optical fibers, which may be single mode optical fiber(s) and/or multicore optical fiber(s). 
     The network device  702  further comprises a plurality of receptacles  735 - 1 , . . . ,  735 - 8  that are each configured to receive a respective pluggable optical module  740 - 1 , . . . ,  740 - 8 . In some embodiments, each of the receptacles  735 - 1 , . . . ,  735 - 8  may be configured as shown in  FIG.  2  or  3    and described above. Each of the optical fibers  745 - 1 , . . . ,  745 - 4  extends from the FAUs ( 730 ) to a respective receptacle  735 - 1 , . . . ,  735 - 4 , such that the pluggable optical modules  740 - 1 , . . . ,  740 - 8  are optically coupled with the photonic dies  720 - 1 , . . . ,  720 - 4 . 
     The pluggable optical modules  740 - 1 , . . . ,  740 - 8  may provide any suitable functionality, such as a laser module unit as shown in  FIGS.  4 A,  4 B , an optical conditioning unit as shown in  FIGS.  5 A,  5 B , a hybrid laser module and optical conditioning unit as shown in  FIG.  6   , and so forth. In some embodiments, each of the pluggable optical modules  740 - 1 , . . . ,  740 - 8  comprises one or more external optical connectors that are arranged at the faceplate  750  when the pluggable optical modules  740 - 1 , . . . ,  740 - 8  are plugged into the respective receptacles  735 - 1 , . . . ,  735 - 8 . The external optical connectors may transmit optical signals to, and/or receive optical signals from, one or more external optical devices. 
     In some embodiments, the plurality of receptacles  735 - 1 , . . . ,  735 - 8  are arranged at the faceplate  750  (e.g., one or more cages  305  of  FIG.  3   ) to define one or more air intake regions  755  at the faceplate  750 . As shown in the diagram  700 , the air intake region  755  is positioned between the receptacles  740 - 2 ,  740 - 3 , although other positioning is also contemplated. In other embodiments, the faceplate  750  need not define an air intake region  755  as large as shown in the diagram  700 . In some embodiments, the faceplate  750  may include one or more additional external optical connectors arranged between the receptacles  740 - 2 ,  740 - 3  (or elsewhere along the faceplate  750 ). In one example configuration, the pluggable optical modules  740 - 1 , . . . ,  740 - 8  may be configured as laser module units that provide optical energy to the photonic dies  720 - 1 , . . . ,  720 - 4 . Based on signals received from the host PCB  705 , the ASIC  715 , and/or the electronic dies  725 , the photonic dies  720 - 1 , . . . ,  720 - 4  provide optical signals (e.g., modulated signals) to the additional external optical connectors. 
       FIGS.  8 A- 8 D  illustrate a sequence of assembling and coupling a host-side connector assembly with connectors of a pluggable optical module, according to one or more embodiments. The features in diagrams  800 ,  840 ,  850 ,  885  may be used in conjunction with other embodiments, e.g., to assemble the host device shown in  FIG.  2  or  3   . 
     In the diagram  800 , a connector  805  is separate from a PCB  835  (e.g., the host PCB  240  of  FIGS.  2 ,  3   ). In some embodiments, the connector  805  comprises a blind mate optical connector. The connector  805  comprises a body  810  that defines a recess  815  from a first lateral surface. An opening  820  extends from the recess  815 , through the body  810 , to a second lateral surface opposite the first lateral surface. 
     The connector  805  further comprises a horizontal projection  825  that forms a bottom surface of the connector  805 . The horizontal projection  825  extends laterally from the first lateral surface. An electrical contact  830  extends from a top surface of the horizontal projection  825 . Although not visible in the diagram  800 , one or more additional electrical connectors may extend from the top surface of the horizontal projection  825 . In some embodiments, the electrical contact  830  is elastically biased. 
     In the diagram  840 , a bottom surface of the connector  805  is attached to a top surface of the PCB  835  using any suitable techniques. Attaching the connector  805  to the PCB  835  electrically couples the one or more electrical contacts  830  with contacts of the PCB  835  along an electrical interface  845 . 
     In the diagram  850 , a pluggable optical module is inserted into the host-side connector assembly. On the pluggable optical module, a blind mate optical connector  855  is attached to a top surface of a module PCB  865 , and an electrical contact  870  is arranged at a bottom surface of the module PCB  865 . The blind mate optical connector  855  is attached to an optical fiber  860 . 
     A forward edge of the blind mate optical connector  855  is received into the recess  815  of the connector  805 . In some embodiments, the blind mate optical connector  855  contacts the connector  805  along a connector interface  880 , which aligns the optical fiber  860  with the opening  820  extending through the body  810 . The electrical contacts  870  contacts the electrical contact  830  along an electrical interface  875 . In some embodiments, the compliance of the electrical contact  830  accommodates the alignment of the connector  805  with the blind mate optical connector  855 . In some embodiments, the blind mate optical connector  855  may be retained by the connector  805  in the contacting relationship, e.g., using latch(es) formed in the connector  805 , an applied adhesive, and so forth. 
     In diagram  885 , a ferrule  890  is attached to an optical fiber  895 . The ferrule  890  is received into the opening  820  and contacts the forward edge of the blind mate optical connector  855 . In other embodiments, one or more features of the connector  805  (e.g., dimensioning of the opening  820 ) may limit the forward travel of the ferrule  890 . In the contacting relationship, the optical fiber  895  is aligned with the optical fiber  860  along the optical axis  899 . In some embodiments, the ferrule  890  may be retained by the connector  805  in the contacting relationship, e.g., using latch(es) formed in the connector  805 , an applied adhesive, and so forth. 
     Although the sequence of diagrams  850 ,  885  illustrates the connection of the blind mate optical connector  855  to the connector  805  before the connection of the ferrule  890  to the connector  805 , an alternate sequence may connect the ferrule  890  to the connector  805  before connecting the blind mate optical connector  855  to the connector  805 . 
       FIG.  9    illustrates a connector assembly having an opening through an endface, according to one or more embodiments. The features in diagram  900  may be used in conjunction with other embodiments, e.g., to assemble the host-side connector assembly as shown in  FIGS.  8 A- 8 D . 
     In the diagram  900 , an electrical connector  905  has an opening  915  through an endface of the electrical connector  905 . Although the external contour of the electrical connector  905  and the opening  915  are square-shaped, alternative shapes are also contemplated. The electrical connector  905  further comprises a horizontal projection  910 . Although not shown, in some embodiments one or more electrical contacts extend from a top surface of the horizontal projection  910 . The one or more electrical contacts may be coupled with electrical contacts of a PCB when the electrical connector  905  is attached to the PCB. 
     An optical connector  920  may operate as a ferrule, defining an opening  925  that receives an optical fiber  930 . The optical fiber  930  may be attached to the optical connector  920 , e.g., using an applied adhesive. The optical connector  920  may be received into the electrical connector  905  through the opening  915 . Although the optical connector  920  is shown as having a square-shaped external contour, the optical connector  920  may have any suitable shaping that corresponds to the contour of the opening  915 . The optical connector  920  may be retained in the contacting relationship with the electrical connector  905  using latches, adhesive, and so forth. The optical fiber  930  may couple with a blind mate optical connector (e.g., of a pluggable optical module) through the opening  915 . 
       FIG.  10    illustrates a connector assembly having an I-shaped endface, according to one or more embodiments. The I-shaped endface may alternately be described as an H-shaped interface. The features in diagram  1000  may be used in conjunction with other embodiments, e.g., to assemble the host-side connector assembly as shown in  FIGS.  8 A- 8 D . 
     In the diagram  1000 , an electrical connector  1005  has an I-shaped endface and defines openings  1010 - 1 ,  1010 - 2 . The electrical connector  1005  further comprises a horizontal projection  1015 . Although not shown, one or more electrical connectors may extend from a top surface of the horizontal projection  1015 . The one or more electrical connectors may be coupled with electrical contacts of a PCB when the electrical connector  1005  is attached to the PCB. 
     An optical connector  1020  may operate as one or more ferrules for one or more optical fibers, and as shown, the optical connector  1020  defines openings  1025 - 1 ,  1025 - 2  that receive respective optical fibers  1030 - 1 ,  1030 - 2 . The optical fibers  1030 - 1 ,  1030 - 2  may be attached to the optical connector  1020 , e.g., using an applied adhesive. As shown, the optical connector  1020  is U-shaped and is received through the openings  1010 - 1 ,  1010 - 2  (i.e., received around the web of the electrical connector  1005 ). The optical connector  1020  may be retained in the contacting relationship with the electrical connector  1005  using latches, adhesive, and so forth. The optical fibers  1030 - 1 ,  1030 - 2  may couple with a blind mate optical connector (e.g., of a pluggable optical module) around the I-shaped endface. 
     Other implementations of the electrical connectors  905 ,  1005  and the optical connectors  920 ,  1020  are also contemplated. In some embodiments, the optical connectors  920 ,  1020  include electrical contacts that couple with corresponding electrical contacts of the electrical connectors  905 ,  1005  when the optical connectors  920 ,  1020  are received. For example, the optical connectors  920 ,  1020  may include electrical contacts along outer surface(s) of the optical connectors  920 ,  1020  that couple with electrical contacts of the electrical connectors  905 ,  1005  exposed at the openings  915 ,  1010 - 1 ,  1010 - 2 . Thus, the electrical contacts of the optical connectors  920 ,  1020  may be coupled, through the electrical connectors  905 ,  1005 , with electrical contacts of a PCB or of a blind mate optical connector. 
     In the current disclosure, reference is made to various embodiments. However, the scope of the present disclosure is not limited to specific described embodiments. Instead, any combination of the described features and elements, whether related to different embodiments or not, is contemplated to implement and practice contemplated embodiments. Additionally, when elements of the embodiments are described in the form of “at least one of A and B,” it will be understood that embodiments including element A exclusively, including element B exclusively, and including element A and B are each contemplated. Furthermore, although some embodiments disclosed herein may achieve advantages over other possible solutions or over the prior art, whether or not a particular advantage is achieved by a given embodiment is not limiting of the scope of the present disclosure. Thus, the aspects, features, embodiments and advantages disclosed herein are merely illustrative and are not considered elements or limitations of the appended claims except where explicitly recited in a claim(s). Likewise, reference to “the invention” shall not be construed as a generalization of any inventive subject matter disclosed herein and shall not be considered to be an element or limitation of the appended claims except where explicitly recited in a claim(s). 
     As will be appreciated by one skilled in the art, the embodiments disclosed herein may be embodied as a system, method or computer program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, embodiments may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon. 
     Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing. 
     Computer program code for carrying out operations for embodiments of the present disclosure may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). 
     Aspects of the present disclosure are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments presented in this disclosure. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the block(s) of the flowchart illustrations and/or block diagrams. 
     These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other device to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the block(s) of the flowchart illustrations and/or block diagrams. 
     The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process such that the instructions which execute on the computer, other programmable data processing apparatus, or other device provide processes for implementing the functions/acts specified in the block(s) of the flowchart illustrations and/or block diagrams. 
     The flowchart illustrations and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments. In this regard, each block in the flowchart illustrations or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. 
     In view of the foregoing, the scope of the present disclosure is determined by the claims that follow.