Abstract: A line replacement unit includes a terminal controller, and a plastic optical fiber serial interface module (POFSIM) coupled between the terminal controller and the data bus. The POFSIM is configured to transmit digital optical signals to the data bus based on electrical signals received from the terminal controller, and transmit electrical signals to the terminal controller based on digital optical signals received from the data bus.

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: A broad-spectral-bandwidth photodetector designed for use with all types of optical fibers used in different avionics networks and sensors and a process for fabricating such photodetectors. A Schottky barrier photodetector is provided that includes germanium, which has a broad spectral response to light in the ultraviolet to near-infrared range (220 to 1600 nm). The provision of a photodetector having a broad spectral response avoids the use of multiple different types of photodetectors and receivers in an avionics platform with different optical fiber networks and sensors.

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.

Abstract: A data communication system is provided. The data communication system includes a data bus, and a line replacement unit including a terminal controller, and a plastic optical fiber serial interface module (POFSIM) coupled between the terminal controller and the data bus. The POFSIM is configured to transmit digital optical signals to the data bus based on electrical signals received from the terminal controller, and transmit electrical signals to the terminal controller based on digital optical signals received from the data bus.

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 optical network architecture can include a first pair of tapered mixing rods and a second pair of tapered mixing rods. The optical network architecture can also include a first plurality of plastic optical fibers communicatively coupled from the first pair of tapered mixing rods to a first plurality of line replaceable units and a second plurality of plastic optical fibers communicatively coupled from the second pair of tapered mixing rods to a second plurality of line replaceable units. The optical network architecture can also include at least one plastic optical fiber communicatively coupled from the first pair of tapered mixing rods to the second pair of tapered mixing rods.

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 airplane fuel level optical sensor using one side-emitting plastic optical fiber (SPOF) and two fluorescent plastic optical fibers (FPOFs) to detect the airplane fuel level without using any electrically conductive component or element placed inside the fuel tank. This dual-FPOF sensor is capable of achieving high resolution and high accuracy with a one-time calibration in the actual airplane's fuel tank environment. One embodiment of the dual-FPOF sensor uses one SPOF and two FPOFs to detect fuel level change based on the optical signal output from the two FPOFs. The sensor design uses large-diameter (core and cladding), lightweight, low-cost and high-durability plastic optical fiber, which is very desirable for airplane installation.

Abstract: A bidirectional, multi-wavelength fiber optical network that enables communication between electrical components (such as line replaceable units) at high data transmission rates. The proposed fiber optical network in accordance with some embodiments comprises a single plastic or glass optical fiber capable of transmitting data at rates faster than 1 Gbits/sec. In accordance with some embodiments, the number of fiber cables between line replaceable units onboard an airplane can be reduced by a factor of eight or more by substituting one gigabit plastic or gigabit glass optical fiber for four or more plastic or glass optical fibers.

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.

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: 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: Systems and methods that use a passive differential optical sensor to measure the level of liquid in a reservoir (e.g., a fuel tank or other storage container). More specifically, the passive differential optical liquid level sensor solves the problem of common-mode intensity variations by employing three optical fibers that will be disposed vertically in the reservoir. The system comprises a side-emitting optical fiber having one end optically coupled to an optical source, a side-receiving optical fiber optically coupled to a first optical detector, and a total internal reflection optical fiber having one end optically coupled to the other end of the side-emitting optical fiber and another end optically coupled to a second optical detector. A computer or processor is configured to perform differential processing of the detected light and then determine the liquid level based on the differential processing results.

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: A method, system, and apparatus are disclosed for a ruggedized photonic crystal (PC) sensor packaging. In particular, the present disclosure teaches a ruggedized packaging for a photonic crystal sensor that includes of a hermetic-seal high-temperature jacket and a ferrule that eliminate the exposure of the optical fiber as well as the critical part of the photonic crystal sensor to harsh environments. The disclosed packaging methods enable photonic crystal based sensors to operate in challenging environments where adverse environmental conditions, such as electromagnetic interference (EMI), corrosive fluids, large temperature variations, and strong mechanical vibrations, currently exclude the use of traditional sensor technologies.

Abstract: A bidirectional, multi-wavelength fiber optical network that enables communication between electrical components (such as line replaceable units) at high data transmission rates. The proposed fiber optical network in accordance with some embodiments comprises a single plastic or glass optical fiber capable of transmitting data at rates faster than 1 Gbits/sec. In accordance with some embodiments, the number of fiber cables between line replaceable units onboard an airplane can be reduced by a factor of eight or more by substituting one gigabit plastic or gigabit glass optical fiber for four or more plastic or glass optical fibers.

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 airplane fuel level optical sensor using one side-emitting plastic optical fiber (SPOF) and two fluorescent plastic optical fibers (FPOFs) to detect the airplane fuel level without using any electrically conductive component or element placed inside the fuel tank. This dual-FPOF sensor is capable of achieving high resolution and high accuracy with a one-time calibration in the actual airplane's fuel tank environment. One embodiment of the dual-FPOF sensor uses one SPOF and two FPOFs to detect fuel level change based on the optical signal output from the two FPOFs. The sensor design uses large-diameter (core and cladding), lightweight, low-cost and high-durability plastic optical fiber, which is very desirable for airplane installation.