Patent Description:
Pluggable optical modules, such as Quad Small Form Factor Pluggable (QSFP)-<NUM> transceiver modules, QSFP-Double Density (DD) transceiver modules, and the like, are continually being driven to higher capacities and smaller sizes and, as a result, are continually being required to withstand higher thermal densities. For example, QSFP modules have evolved from <NUM>-Gb/s rates to <NUM>-Gb/s rates, and new ports supporting both QSFP and <NUM>-Gb/s QSFP-DD modules are now available. Ports that were previously designed for <NUM>-W power dissipation are now required to accommodate <NUM>-<NUM> W optical modules. Further, in order to provide dual-use ports that can accommodate both QSFP-<NUM> and QSFP-DD modules, for example, a considerable portion of the housings of these modules must often protrude outside of the associated face plate. For example, ports supporting QSFP-DD modules are required to support module housings that protrude by varying amounts, as well as supporting legacy module housings that sit flush with the associated face plate.

This combination of increased power dissipation in a module housing that extends beyond the associated face plate results in a potential safety concern when the module housing temperature exceeds <NUM> degrees C, as such elevated temperatures can injure a user. The typical specification for maximum module housing temperature is <NUM> degrees C, although some modules are designed to tolerate <NUM>-degree C housing temperatures for short term operation. Hardened optical modules may be designed to tolerate maximum module housing temperatures as high as <NUM> degrees C when operated in extreme environmental conditions. Under any of these circumstances, inserting or removing an optical fiber into or from the metal surfaces of such a module housing presents a significant safety concern.

As a result, there is a need in the art for pluggable optical modules that are prevented from reaching potentially dangerous temperatures when a fiber optic connector is not present and engaged with the associated module housing. Further, there is a need in the art for pluggable optical modules and/or fiber optic connectors that incorporate a port heat shield external to the associated face plate when the pluggable optical modules and fiber optic connectors are engaged, thereby preventing a user from contacting potentially hot and dangerous metallic surfaces of the module housings, as well as providing access for cooling air flow. <CIT> describes an optical connector receptacle having switching capability. <CIT> describes an optical connector plug. <CIT> describes an adapter for a light guide for a medical laser apparatus. <CIT> describes a laser transmitter interlock. <CIT> describes a device for preventing laser beam leakage. <CIT> describes an optical connector assembly. <CIT> describes a plug connector system and protective device for optical plug connectors.

The invention provides a pluggable optical module as defined in claim <NUM>. Accordingly, the pluggable optical module of the present disclosure includes a port configured to selectively receive a fiber optic connector that incorporates a fiber connector detection mechanism. This fiber connector detection mechanism automatically transitions the pluggable optical module from a high power state when the fiber optic connector is present and engaged with the port of the pluggable optical module to a low power state when the fiber optic connector is otherwise disengaged from the port of the pluggable optical module, thereby limiting the module housing temperature when the fiber optic connector is disengaged from the port of the pluggable optical module. The fiber connector detection mechanism includes a mechanical, magnetic, electrical, and/or optical fiber connector detection mechanism that is actuated by the presence/absence of the fiber optic ferrule, connector housing, and/or spring loaded connector latch mechanism when the fiber optic connector is engaged with/disengaged from the port of the pluggable optical module.

Optionally, the fiber connector detection mechanism includes a mechanical detection mechanism adapted to be actuated via contact with one or more physical surfaces associated with an end portion of the fiber optic connector
Alternatively, the fiber connector detection mechanism includes an electrical detection mechanism adapted to be actuated via contact with one or more conductive surfaces associated with an end portion of the fiber optic connector. Alternatively, the fiber connector detection mechanism includes an optical detection mechanism adapted to be actuated via interaction with one or more physical surfaces associated with an end portion of the fiber optic connector. Alternatively, the fiber connector detection mechanism includes a mechanical or magnetic sensor. Optionally, the low power operating state is a laser-off operating state.

In an unclaimed embodiment, the present disclosure provides a method for managing the power operating state of a pluggable optical module, including: operating the pluggable optical module in a high power operating state when a fiber optic connector is engaged with a port defined by a housing of the pluggable optical module; operating the pluggable optical module in a low power operating state when the fiber optic connector is disengaged from the port defined by the housing of the pluggable optical module; and selectively transitioning the pluggable optical module between the high power operating state and the low power operating state upon the insertion/removal of the fiber optic connector into/from the port defined by the housing of the pluggable optical module, where the housing of the pluggable optical module includes a fiber connector detection mechanism disposed one of within and adjacent to the port, and where the fiber connector detection mechanism is adapted to be actuated by the insertion/removal of the fiber optic connector into/from the port, thereby transitioning the pluggable optical module between the high power operating state and the low power operating state. Optionally, the fiber connector detection mechanism includes a mechanical detection mechanism adapted to be actuated via contact with one or more physical surfaces associated with an end portion of the fiber optic connector. Alternatively, the fiber connector detection mechanism includes an electrical detection mechanism adapted to be actuated via contact with one or more conductive surfaces associated with an end portion of the fiber optic connector. Alternatively, the fiber connector detection mechanism includes an optical detection mechanism adapted to be actuated via interaction with one or more physical surfaces associated with an end portion of the fiber optic connector. Alternatively, the fiber connector detection mechanism includes a mechanical or magnetic sensor. Optionally, the low power operating state is a laser-off operating state.

The fiber optic connector and/or pluggable optical module of the present disclosure also includes a separate port heat shield disposed external to the associated face plate when the pluggable optical module and fiber optic connector are engaged, thereby preventing a user from contacting potentially hot and dangerous metallic surfaces of the module housing, as well as providing access for cooling air flow. Optionally, the heat shield can be deployed as part of the fiber optic connector or patch cord. When the fiber optic connector is engaged with the port of the pluggable optical module (or other port), the heat shield provides protection for the portion of the housing protruding from or otherwise accessible through the associated face plate. A meshed structure or appropriate holes, for example, are utilized to provide the cooling air flow access. The exact configuration of the heat shield is dependent upon the specific module packaging and application. For example, for belly-to-belly mounted modules in a router configuration, shielding on a single surface of the fiber optic connector may be sufficient, while for transponder applications, it may be desirable to shield multiple surfaces of the fiber optic connector. The heat shield can be formed as part of the fiber optic connector itself, or may simply be coupled to the fiber optic connector. This may necessitate the use of a longer connector spring retention mechanism than is typically utilized, or the use of pull-tab type connector latch mechanism, well known to those of ordinary skill in the art. Alternatively, the connector spring retention mechanism can be coupled to and/or actuated through the heat shield. It is also contemplated herein that the heat shield can be a separate component from the fiber optic connector and/or can be coupled to the pluggable optical module and/or associated face plate. For modules without a separable optical connector, the heat shield could be integrated into the module pull-tab, and the module pull-tabs could be used essentially as side heat shields. In any event, this heat shield concept is becoming more and more important as higher power pluggable coherent modules are becoming more and more prevalent.

A fiber optic connector and optical module heat shield assembly which is not claimed on its own is also described herein, including: an isolating clip structure including a retention portion one of fixedly and removably coupled to an end portion of the fiber optic connector and a protection portion adapted to be one of fixedly and removably disposed about an exposed end portion of the optical module; wherein the isolating clip structure defines a protective envelope about a port interface between the fiber optic connector and the optical module and the exposed end portion of the optical module. The protection portion of the isolating clip structure is adapted to be one of fixedly and removably disposed about one or more of an exposed top surface, and exposed bottom surface, and an exposed side surface of the optical module. The retention portion of the isolating clip structure is adapted to receive the end portion of the fiber optic connector therethrough. Optionally, the retention portion of the isolating clip structure is disposed at an angle with respect to the protection portion of the isolating clip structure.

A heat shield device which is not claimed on its own for use with a fiber optic connector and an optical module is also described herein, including: an isolating clip structure including a retention portion adapted to receive an end portion of the fiber optic connector and a protection portion adapted to be disposed about an exposed end portion of the optical module; wherein the isolating clip structure defines a protective envelope about a port interface between the fiber optic connector and the optical module and the exposed end portion of the optical module. The protection portion of the isolating clip structure is adapted to be disposed about one or more of an exposed top surface, and exposed bottom surface, and an exposed side surface of the optical module. The retention portion of the isolating clip structure is adapted to receive the end portion of the fiber optic connector therethrough. Optionally, the retention portion of the isolating clip structure is disposed at an angle with respect to the protection portion of the isolating clip structure. The optical module may be a QSFP-DD pluggable optical module. The isolating clip structure may include a heat insulating material. The isolating clip structure may include a surface treatment to reduce one or more of conductive and radiative heat transfer from the optical module. The heat shield may be placed over the fiber optic connector. A method is also described herein comprising: providing a heat shield device including an isolating clip structure with a retention portion one of fixedly and removably coupled to an end portion of a fiber optic connector and a protection portion adapted to be one of fixedly and removably disposed about an exposed end portion of an optical module; wherein the isolating clip structure defines a protective envelope about a port interface between the fiber optic connector and the optical module and the exposed end portion of the optical module. In the method, the protection portion of the isolating clip structure may be adapted to be one of fixedly and removably disposed about one or more of an exposed top surface, and exposed bottom surface, and an exposed side surface of the optical module. In the method, the retention portion of the isolating clip structure may be adapted to receive the end portion of the fiber optic connector therethrough. In the method, the retention portion of the isolating clip structure may be disposed at an angle with respect to the protection portion of the isolating clip structure. In the method, the optical module may be a QSFP-DD pluggable optical module. In the method, the isolating clip structure may include a heat insulating material. In the method, the isolating clip structure may include a surface treatment to reduce one or more of conductive and radiative heat transfer from the optical module.

The assemblies, devices, and methods of the present disclosure are illustrated and described herein with reference to the various drawings, in which like reference numbers are used to denote like assembly/device components and/or method steps, as appropriate, and in which:.

Again, the pluggable optical module of the present disclosure includes a port configured to selectively receive a fiber optic connector that incorporates a fiber connector detection mechanism. This fiber connector detection mechanism automatically transitions the pluggable optical module from a high power state when the fiber optic connector is present and engaged with the port of the pluggable optical module to a low power state when the fiber optic connector is otherwise disengaged from the port of the pluggable optical module, thereby limiting the module housing temperature when the fiber optic connector is disengaged from the port of the pluggable optical module. The fiber connector detection mechanism includes a mechanical, magnetic, electrical, and/or optical fiber connector detection mechanism that is actuated by the presence/absence of the fiber optic ferrule, connector housing, and/or spring loaded connector latch mechanism when the fiber optic connector is engaged with/disengaged from the port of the pluggable optical module.

Referring now specifically to <FIG>, in one exemplary embodiment, the pluggable optical module <NUM> includes a housing <NUM> that defines a port <NUM> that is configured and adapted to selectively and securely receive the end portion <NUM> of a fiber optic connector <NUM>, such as an LC connector or the like, well known to those of ordinary skill in the art. When the fiber optic connector <NUM> is engaged with the pluggable optical module, the optical fiber <NUM> of the fiber optic connector <NUM> is optically coupled to the optical fiber <NUM> of the pluggable optical module <NUM>, such that optical signals may be communicated between and through the two. Of course, each fiber optic connector <NUM> and port <NUM> can similarly couple multiple optical fibers <NUM>,<NUM> simultaneously. Typically, the fiber optic connector <NUM> is introduced into and secured to/released from the port <NUM> via the actuation of a spring retention mechanism <NUM> or the like, well known to those of ordinary skill in the art.

At the opening of the port <NUM> or within an interior portion of the port <NUM>, the fiber connector detection mechanism <NUM> is provided. In a mechanical arrangement, the fiber connector detection mechanism <NUM> includes a pivotable arm or push pin that is displaced by the fiber optic connector <NUM> when the fiber optic connector <NUM> is inserted into the port <NUM>. This actuation triggers a control mechanism or algorithm that transitions the pluggable optical module <NUM> from a low power state to a high power state, causing the intensity of the optical signal, and the corresponding temperature of the housing <NUM> of the pluggable optical module <NUM>, to be increased. Alternately, when the fiber optic connector <NUM> is removed from the port <NUM>, the fiber connector detection mechanism <NUM> is actuated to transition the pluggable optical module <NUM> from the high power state to the low power state, causing the intensity of the optical signal, and the corresponding temperature of the housing <NUM> of the pluggable optical module <NUM>, to be decreased. The control mechanism or algorithm may involve mechanical and/or software-based control. <FIG> illustrates the fiber connector detection mechanism <NUM> in an unactuated configuration, with the fiber optic connector <NUM> partially disengaged from the port <NUM>. <FIG> illustrates the fiber connector detection mechanism <NUM> in an actuated configuration, with the fiber optic connector <NUM> engaged with the port <NUM>.

The fiber connector detection mechanism <NUM> could also utilize a magnet coupled to the fiber optic connector <NUM> or displaced by the fiber optic connector <NUM> that is sensed by a magnetic sensor or the like present in or adjacent to the port. The fiber connector detection mechanism <NUM> could further utilize a mechanical connection between the fiber optic connector <NUM> and the pluggable optical module <NUM> that closes an internal electrical or optical detection associated with the pluggable optical module <NUM>. The fiber connector detection mechanism <NUM> could still further utilize a sensor that senses optical fiber <NUM>,<NUM> displacement when the fiber optic connector <NUM> is engaged with/removed from the port <NUM>. It will be readily apparent to those of ordinary skill in the art that any suitable type of fiber connector detection mechanism <NUM>, whether mechanical, electrical, and/or optical, could be utilized equally, provided that the insertion of the fiber optic connector <NUM> into or removable of the fiber optic connector <NUM> from the port <NUM> of the pluggable optical module <NUM> causes the corresponding transition of the pluggable optical module <NUM> between the low power state and the high power state. For example, the fiber optic connector <NUM> could close a connection via insertion through a spring loaded dust cover disposed over the port <NUM> or the like.

Although the focus of the present disclosure is primarily directed to protecting a user from hot surfaces associated with the housing <NUM> of the pluggable optical module <NUM>, via the transition of the pluggable optical module <NUM> from a high power state to a low power state when the fiber optic connector <NUM> is removed from the port <NUM>, this same fiber connector detection mechanism <NUM> could be used to address laser safety as well, providing automatic shutdown of the associated laser when the fiber optic connector <NUM> is removed from the port <NUM> and the fiber connector detection mechanism <NUM> is actuated accordingly. The functionality provided herein can be programmed using a management interface, and can be incorporated into a fixed optical port, as well as the pluggable optical module port <NUM> illustrated. The functionality provided herein finds particular applicability with QSFP-DD pluggable optical modules and the like, where the current state-of-the-art user protection methodology is the use of warning labels on face plates, providing no physical user protection. When a user removes a fiber optic connector <NUM> from a port <NUM> there is currently significant risk of contact with hot surfaces.

Again, the fiber optic connector and/or pluggable optical module of the present disclosure also includes a port heat shield disposed external to the associated face plate when the pluggable optical module and fiber optic connector are engaged, thereby preventing a user from contacting potentially hot and dangerous metallic surfaces of the module housing, as well as providing access for cooling air flow. Optionally, the heat shield can be deployed as part of the fiber optic connector or patch cord. When the fiber optic connector is engaged with the port of the pluggable optical module (or other port), the heat shield provides protection for the portion of the housing protruding from or otherwise accessible through the associated face plate. A meshed structure or appropriate holes are utilized to provide the cooling air flow access. The exact configuration of the heat shield is dependent upon the specific module packaging and application. For example, for belly-to-belly mounted modules in a router configuration, shielding on a single surface of the fiber optic connector may be sufficient, while for transponder applications, it may be desirable to shield multiple surfaces of the fiber optic connector. The heat shield can be formed as part of the fiber optic connector itself, or may simply be coupled to the fiber optic connector. This may necessitate the use of a longer connector spring retention mechanism than is typically utilized, or the use of pull-tab type connector latch mechanism, well known to those of ordinary skill in the art. Alternatively, the connector spring retention mechanism can be coupled to and/or actuated through the heat shield. It is also contemplated herein that the heat shield can be a separate component from the fiber optic connector and/or can be coupled to the pluggable optical module and/or associated face plate. For modules without a separable optical connector, the heat shield could be integrated into the module pull-tab, and the module pull-tabs could be used essentially as side heat shields. In any event, this heat shield concept is becoming more and more important as higher power pluggable coherent modules are becoming more and more prevalent.

Referring now specifically to <FIG>, in one exemplary embodiment, the heat shield <NUM> provided herein is fixedly or removably coupled to the end portion <NUM> of the fiber optic connector <NUM> and surrounds the portion of the housing <NUM> of the pluggable optical module <NUM> that protrudes from the associated face plate when the fiber optic connector <NUM> is engaged with the port <NUM> of the pluggable optical module <NUM>. In the exemplary embodiment illustrated, the heat shield <NUM> covers both the top and bottom protruding surfaces of the housing <NUM>, although it may cover the top protruding surface or the bottom protruding surface alone, and it may also cover the side protruding surfaces. The heat shield <NUM> can be fixedly or removably coupled to the end portion <NUM> of the fiber optic connector <NUM> itself, the associated patch cord, or the associated latch mechanism <NUM> that secures the fiber optic connector <NUM> in the port <NUM> of the pluggable optical module <NUM>. Alternatively (or in addition), the heat shield <NUM> can be fixedly or removably coupled to one or more of the protruding surfaces of the housing <NUM> of the pluggable optical module <NUM> and/or the associated faceplate. Thus, in general, the heat shield <NUM> is disposed about the interface of the fiber optic connector <NUM> and the port <NUM> of the pluggable optical module <NUM>, shielding the protruding surfaces of the housing <NUM> of the pluggable optical module <NUM> from user contact, regardless of which structures the heat shield <NUM> is actually coupled to. In the event that a fixed port is used, with a fixed fiber optic line, the heat shield <NUM> may be similarly disposed, protecting any protruding metallic surfaces around the fixed port from user contact. The heat shield <NUM> is most simply manufactured from an insulating plastic material or the like that is not prone to heating up. Additionally, it may be enhanced by inclusion of selective surface treatments to reduce conductive and/or radiative heat transfer from the module/transponder to the heat shield <NUM>. Such treatments may include surface contouring on a micro or macro scale to increase contact resistance on mating surfaces, the use of non-absorbing surface treatments or materials that limit radiation heat transfer, and the inclusion of thermally resistive materials in contact locations, while outer portions may selectively utilize conductive material to reduce temperatures where personnel contact the heat shield <NUM>.

Referring now specifically to <FIG> and <FIG>, in one specific exemplary embodiment, the heat shield <NUM> includes an isolating clip structure <NUM> that has a fiber optic connector retention portion <NUM> adapted to receive and retain one or more fiber optic connectors <NUM>. For example, the one or more fiber optic connectors <NUM> can be "snapped" into the fiber optic connector retention portion <NUM>. The isolating clip structure <NUM> also has a housing protection portion <NUM> that is adapted to engage and surround one or more protruding surfaces of the housing <NUM> of the pluggable optical module <NUM>. In the embodiment illustrated, the housing protection portion <NUM> engages and surrounds the top and bottom protruding surfaces of the housing <NUM>, but not the side protruding surfaces. In this sense, the isolating clip structure <NUM> retains a pair of fiber optic connectors <NUM>, for example, and then "clips" about the protruding portion of the housing <NUM> when the pair of fiber optic connectors <NUM> are engaged with the pluggable optical module <NUM>, especially when the pluggable optical module is in a high power, high temperature operating state. Accordingly, the isolating clip structure <NUM> defines one or more thru holes <NUM> that allow a cooling air flow to penetrate the heat shield <NUM> and reach the protruding portion of the housing <NUM>.

<FIG> illustrates the isolating clip structure <NUM> with the pair of fiber optic connectors <NUM> secured in the fiber optic connector retention portion <NUM>. <FIG> illustrates the isolating clip structure <NUM> with the pair of fiber optic connectors <NUM> disengaged from the fiber optic connector retention portion <NUM>. It should be noted that the fiber optic connector retention portion <NUM> of the isolating clip structure <NUM> can be formed to substantially conform to the shape of the retained fiber optic connector(s) <NUM>, or the fiber optic connector retention portion <NUM> of the isolating clip structure <NUM> can be integrally formed with the retained fiber optic connector(s) <NUM>. The isolating clip structure <NUM> can also be coupled to the patch cord(s) <NUM> of the fiber optic connector(s) <NUM>.

As alluded to herein above, the isolating clip structure <NUM> can alternatively be coupled to one or more of the pluggable optical module <NUM> (<FIG>) and the associated face plate, with the fiber optic connector(s) <NUM> simply passing through the heat shield <NUM> to engage the pluggable optical module <NUM>, provided that the interface between the two is shielded from user contact.

Again, the heat shield assemblies and devices provided herein find particular applicability with QSFP-DD pluggable optical modules and the like, where the current state-of-the-art user protection methodology is the use of warning labels on face plates, providing no physical user protection. When a user removes a fiber optic connector <NUM> from a port <NUM> there is currently significant risk of contact with hot surfaces.

Claim 1:
A pluggable optical module (<NUM>) comprising:
a housing (<NUM>) that defines a port (<NUM>) that is configured and adapted to selectively and securely receive an end portion (<NUM>) of a fiber optic connector (<NUM>), wherein a portion of the housing (<NUM>) protrudes outside of an associated face plate;
a fiber connector detection mechanism (<NUM>) configured to automatically transition the pluggable optical module (<NUM>) between a high power state when the fiber optic connector (<NUM>) is present and engaged with the port (<NUM>) and a low power state when the fiber optic connector (<NUM>) is otherwise disengaged from the port (<NUM>), and
a heat shield (<NUM>) fixedly or removably coupled to the end portion (<NUM>), wherein, when the fiber optic connector (<NUM>) is engaged with the pluggable optical module (<NUM>):
the heat shield (<NUM>) is disposed about the interface of the fiber optic connector (<NUM>) and the port (<NUM>) of the pluggable optical module (<NUM>) so as to shield the portion of the housing (<NUM>) of the pluggable optical module (<NUM>) that protrudes outside of the face plate from user contact, and
an optical fiber (<NUM>) of the fiber optic connector (<NUM>) is optically coupled to an optical fiber (<NUM>) of the pluggable optical module (<NUM>), such that an optical signal is communicated between and through the two;
wherein a transition from the low power state to the high power state causes an intensity of the optical signal, and the corresponding temperature of the housing (<NUM>) of, to be increased, and
wherein a transition from the high power state to the low power state causes the intensity of the optical signal, and the corresponding temperature of the housing (<NUM>) of, to be decreased, for protecting a user from hot surfaces associated with the housing (<NUM>).