Abstract: High-energy optical disinfection systems inside a commercial airplane using highly efficient, flexible, and durable side-emitting optical fibers optically coupled to high-energy UV-C laser diodes to destroy submicroscopic infectious agents and inactivate microorganisms inside the airplane. With the high-energy UV-C laser diodes optically coupled to the side-emitting optical fibers, which can be easily routed to different areas inside the airplane, the high-energy UV-C laser light emitted from the side of the optical fiber will disinfect the airplane along a wide or long swath continuously without interruption.

Abstract: An optical network architecture can include a first pair of tapered mixing rods and a second pair of tapered mixing rods. A first plurality of plastic optical fibers is communicatively coupled from the first pair of tapered mixing rods to a first plurality of line replaceable components, and a second plurality of plastic optical fibers is communicatively coupled from the second pair of tapered mixing rods to a second plurality of line replaceable components. At least one optical fiber communicatively coupled from the first pair of tapered mixing rods to the second pair of tapered mixing rods, the at least one optical transmission line comprising a hard clad silica optical fiber.

Abstract: High-energy optical disinfection systems inside a commercial airplane using highly efficient, flexible, and durable side-emitting optical fibers optically coupled to high-energy UV-C laser diodes to destroy submicroscopic infectious agents and inactivate microorganisms inside the airplane. With the high-energy UV-C laser diodes optically coupled to the side-emitting optical fibers, which can be easily routed to different areas inside the airplane, the high-energy UV-C laser light emitted from the side of the optical fiber will disinfect the airplane along a wide or long swath continuously without interruption.

Abstract: An optical subassembly includes a housing, a laser package, and first and second end sections of side-emitting optical fiber. The housing defines first, second, and third channels which extend from a central space. The laser package is affixed to the third channel and comprises an edge-emitting UV-C laser diode disposed in the central space and having first and second edges. The first end section of side-emitting optical fiber is retained in the first channel and has a first end face which confronts the first edge. The second end section of side-emitting optical fiber is retained in the second channel and has a second end face which confronts the second edge. The housing further defines a fourth channel which extends from the central space. The optical subassembly further includes a transparent window seated in an opening of the fourth channel.

Abstract: Methods for providing flammability protection for plastic optical fiber (POF) embedded inside avionics line replaceable units (LRUs) or other equipment used in airborne vehicles such as commercial or fighter aircrafts. A thin and flexible flammability protection tube is placed around the POF. In one proposed implementation, a very thin (100 to 250 microns in wall thickness) polyimide tube is placed outside and around the POF cable embedded inside an LRU or other equipment. The thin-walled polyimide tube does not diminish the flexibility of the POF cable.

Abstract: A process for polishing the end face of a gigabit plastic optical fiber (GbPOF) to produce a mirror smooth surface without any defect. Smooth GbPOF end faces reduce the optical coupling loss when two plastic optical fibers are connected. The polishing process can be used to produce GbPOF end faces which are free of defects such as scratches. The polishing process involves the use of successive abrasive films having decreasing surface roughness to abrade the end of a GbPOF. More specifically, each subsequently applied abrasive film has a mean particle size which is less than the mean particle size of the previously applied abrasive film.

Abstract: A process for polishing the end face of a gigabit plastic optical fiber (GbPOF) to produce a mirror smooth surface without any defect. Smooth GbPOF end faces reduce the optical coupling loss when two plastic optical fibers are connected. The polishing process can be used to produce GbPOF end faces which are free of defects such as scratches. The polishing process involves the use of successive abrasive films having decreasing surface roughness to abrade the end of a GbPOF. More specifically, each subsequently applied abrasive film has a mean particle size which is less than the mean particle size of the previously applied abrasive film.

Abstract: A process to enhance the performance of plastic optical fiber to operate with a high data rate (e.g., at least 1 gigabit per second) at high temperature (e.g., 100 degrees Celsius) for airplane avionic systems. Gigabit plastic optical fiber has a core including a dopant that enables data transmission at gigabit rates. The enhancement process uses rapid thermal cooling of the gigabit plastic optical fiber to stabilize the polymer matrix of the fiber. This rapid cooling treatment blocks dopant diffusion in a high-temperature environment, thereby avoiding degradation of the fiber's bandwidth and optical loss characteristic. Such degradation typically occurs in gigabit plastic optical fiber having core and cladding made of transparent carbon-hydrogen bond-free perfluorinated polymer.

Abstract: A process to enhance the performance of plastic optical fiber to operate with a high data rate (e.g., at least 1 gigabit per second) at high temperature (e.g., 100 degrees Celsius) for airplane avionic systems. Gigabit plastic optical fiber has a core including a dopant that enables data transmission at gigabit rates. The enhancement process uses rapid thermal cooling of the gigabit plastic optical fiber to stabilize the polymer matrix of the fiber. This rapid cooling treatment blocks dopant diffusion in a high-temperature environment, thereby avoiding degradation of the fiber's bandwidth and optical loss characteristic. Such degradation typically occurs in gigabit plastic optical fiber having core and cladding made of transparent carbon-hydrogen bond-free perfluorinated polymer.

Abstract: A fuel sensing system utilizes non-contact plastic optical fiber (POF) to optically sense the level of liquid fuel in a fuel tank. In one implementation, the fuel level sensing system includes the following elements: (i) a high-speed and high-power red laser diode; (ii) an ultra-high-sensitivity photon-counting avalanche photodiode; and (iii) a large-diameter and large-numerical-aperture graded-index POF. The fuel level is sensed when the avalanche photodiode first detects impinging light reflected by the POF end face and then detects impinging light reflected by the fuel surface in response to emission of a laser pulse by the red laser diode. A time delay detection circuit calculates the time interval separating the respective times of arrival. A fuel level calculator calculates the fuel level based on the time interval provided by the time delay detection circuit.

Abstract: An epoxy-free, high-durability and low-cost plastic optical fiber splice design and fabrication process which meets commercial airplane environmental requirements. The splice design: (1) does not require the use of epoxy to join the end faces of two plastic optical fibers together; (2) incorporates double-crimp rings to provide highly durable pull force for the plastic optical fibers that are joined together; (3) resolves any vibration problem at the plastic optical fiber end faces using a miniature stop inside a splice alignment sleeve; and (4) incorporates a splice alignment sleeve that can be mass produced using precision molding or three-dimensional printing processes.

Abstract: An apparatus configured to function as a pluggable active optical connector that is modular with one or more channels and that converts electrical signals to optical signals and vice versa. On one side, the apparatus has a pluggable electrical interface to a line replaceable unit (LRU); on the other side the apparatus has a pluggable optical interface side to an aircraft fiber optic wiring bundle. The apparatus is pluggable to different types of LRUs including rack-mounted and bolted-down LRUs. The apparatus includes electronic and photonic components sufficient to enable electrical/optical conversion totally within a standard-sized aircraft connector. The apparatus is adaptable to various data communication protocols and has the flexibility to be used in either a single-fiber or a dual-fiber bidirectional data link.

Abstract: Systems and methods that use a differential spectral liquid level sensor to measure the level of liquid in a reservoir (e.g., a fuel tank or other storage container). The use of a differential spectral liquid level sensor solves the problem of common-mode intensity variations (i.e., intensity variations not due to the level of the liquid) by having two different wavelengths propagate through the same optical path but have different spectral attenuations in the liquid. By determining the ratio of the received optical powers, common-mode intensity variations can be neutralized, thereby enhancing the accuracy of the received power reading and the resulting liquid level indication.

Abstract: A fuel sensing system utilizes non-contact plastic optical fiber (POF) to optically sense the level of liquid fuel in a fuel tank. In one implementation, the fuel level sensing system includes the following elements: (i) a high-speed and high-power red laser diode; (ii) an ultra-high-sensitivity photon-counting avalanche photodiode; and (iii) a large-diameter and large-numerical-aperture graded-index POF. The fuel level is sensed when the avalanche photodiode first detects impinging light reflected by the POF end face and then detects impinging light reflected by the fuel surface in response to emission of a laser pulse by the red laser diode. A time delay detection circuit calculates the time interval separating the respective times of arrival. A fuel level calculator calculates the fuel level based on the time interval provided by the time delay detection circuit.

Abstract: A ruggedized hermetic optical fiber connector and methods for fabricating such an optical fiber connector which has both durability and hermeticity. The hermetic optical fiber connector is epoxy free and hermeticity is achieved by a sequence of high-temperature soldering steps with a proper soldering temperature hierarchy. The design of the hermetic optical fiber connector is universal for both glass optical fiber and plastic optical fiber connections. In addition, the universal hermetic optical fiber connector is ruggedized to withstand harsh avionics environments without incurring optical fiber damage inside the connector.

Abstract: A method for modifying a low-cost small form factor pluggable optical-electrical bidirectional transceiver (hereinafter “SFP transceiver”) by converting the SFP transceiver into a dual-in-line package. Such conversion enables the SFP transceiver to be soldered directly on a printed circuit board of a line replaceable unit of an avionics system, thereby eliminating the concern that the SFP transceiver may become detached due to vibration during aircraft operation. The method also includes a sealing process to protect the contact pads on the SFP transceiver, thereby eliminating any concern that the contact pads could corrode due to long-term moisture and humidity exposure. The product of the method is a ruggedized SFP transceiver capable of withstanding the rigors of operating in a harsh avionics environment onboard an aircraft.

Abstract: An apparatus configured to function as a pluggable active optical connector that is modular with one or more channels and that converts electrical signals to optical signals and vice versa. On one side, the apparatus has a pluggable electrical interface to a line replaceable unit (LRU); on the other side the apparatus has a pluggable optical interface side to an aircraft fiber optic wiring bundle. The apparatus is pluggable to different types of LRUs including rack-mounted and bolted-down LRUs. The apparatus includes electronic and photonic components sufficient to enable electrical/optical conversion totally within a standard-sized aircraft connector. The apparatus is adaptable to various data communication protocols and has the flexibility to be used in either a single-fiber or a dual-fiber bidirectional data link.

Abstract: Methods for providing flammability protection for plastic optical fiber (POF) embedded inside avionics line replaceable units (LRUs) or other equipment used in airborne vehicles such as commercial or fighter aircrafts. A thin and flexible flammability protection tube is placed around the POF. In one proposed implementation, a very thin (100 to 250 microns in wall thickness) polyimide tube is placed outside and around the POF cable embedded inside an LRU or other equipment. The thin-walled polyimide tube does not diminish the flexibility of the POF cable.

Abstract: A controller area network (CAN) comprising a plurality of CAN nodes that communicate via a CAN bus that comprises a fiber optical network. The fiber optical network uses a single fiber and a single wavelength for transmit and receive, and comprises a passive reflective optical star. The reflective optical star comprises an optical mixing rod having a mirror at one end. The other end of the reflective optical star is optically coupled to the transmitters and receivers of a plurality of optical-electrical media converters by way of respective high-isolation optical Y-couplers. Each CAN node produces electrical signals (in accordance with the CAN message-based protocol) which are converted into optical pulses that are broadcast to the fiber optical network. Those optical pulses are then reflected back to all CAN nodes by the reflective optical star.

Abstract: An apparatus configured to function as a pluggable single-wavelength bidirectional transceiver in a switching network. The apparatus includes: a 2×1 fusion coupler; an input/output optical fiber, a detector optical subassembly (OSA) fiber and a laser OSA fiber all connected to the 2×1 fusion coupler; and a transceiver that includes a transceiver electronic circuit printed wiring board (PWB) and laser and detector OSAs electrically coupled to the transceiver electronic circuit PWB. The laser OSA includes a laser that is situated to transmit light to the laser OSA fiber, while the detector OSA includes a photodetector that is situated to receive light from the detector OSA fiber. The transceiver electronic circuit PWB also includes a multiplicity of transceiver input/output metal contacts arranged at one pluggable end of the PWB.