Abstract: A system and a method for generating an arbitrary waveform of a microwave photon based on optical frequency tuning are provided. The system includes an optical frequency comb, a first optical distribution unit, a first photoelectric conversion unit, a frequency-shift drive circuit, and an optical frequency doubling/dividing unit, an optical frequency-shift combining optical circuit, a second photoelectric conversion unit, and a second electrical processing circuit. The optical frequency comb is used as the frequency source, with the features of high stability and low phase noise of the optical frequency comb, the arbitrary waveforms of microwave photons can be generated through optical frequency tuning control; the performance of the optical frequency comb is three orders of magnitude or more higher than that of the common microwave frequency sources, therefore, the waveforms with high-frequency, ultra-wideband, low phase noise, and high stability can be generated.

Abstract: This application provides an example light source switching apparatus. The apparatus includes first and second multi-mode interference (MMI) couplers, and a phase modulator. The first MMI coupler includes four ports, where first and second ports are located on one side, and third and fourth ports are located on the other side. The second MMI coupler includes three ports, where fifth and sixth ports are located on one side, and a seventh port is located on the other side. The first and the second ports connect to the fifth and the sixth ports, respectively, to form two connections. The phase modulator is disposed on one of the two connections, and the seventh port connects to an optical modulator. Both the third and the fourth ports connect to a light source emitting continuous light, and the phase modulator selects one of the two light sources for output from the seventh port.

Abstract: This application provides an example light source switching apparatus. The apparatus includes first and second multi-mode interference (MMI) couplers, and a phase modulator. The first MMI coupler includes four ports, where first and second ports are located on one side, and third and fourth ports are located on the other side. The second MMI coupler includes three ports, where fifth and sixth ports are located on one side, and a seventh port is located on the other side. The first and the second ports connect to the fifth and the sixth ports, respectively, to form two connections. The phase modulator is disposed on one of the two connections, and the seventh port connects to an optical modulator. Both the third and the fourth ports connect to a light source emitting continuous light, and the phase modulator selects one of the two light sources for output from the seventh port.

Abstract: Devices implementing light communications use waveguides to efficiently collect wavelength-specific light used for the light communications and propagate that collected light to a sensor. More particularly, light comprising a plurality of wavelengths and collected from one or more entrances propagates along a TIR waveguide until disrupted by a diffusive element, which effectively directs the propagating light to one or more sensors. Each sensor detects a subset of the plurality of wavelengths. In so doing, the solution presented herein increases the amount of light available for the light communications and/or reduces the number of sensors needed for the light communications, e.g., by providing light collected from multiple different locations to a single sensor. The waveguide solution presented herein may be implemented inside a device and/or along an exterior surface, e.g., housing or casing, of a device.

Abstract: An optical module includes an optical element including a light emitting section, a first wiring board, on a first principal plane of which the optical element is mounted, a ferrule functioning as a holding member including a through hole and disposed on a second principal plane of the first wiring board, an optical fiber inserted into the through hole of the ferrule, a side surface wiring board, a third principal plane of which is disposed in parallel to an optical axis and an end portion of which is connected to the first wiring board, an electrode being disposed on a fourth principal plane of the side surface wiring board, and a signal cable having a distal end portion bonded to the electrode of the side surface wiring board.

Abstract: The application discloses a polymer-based optical splitter on a silicon surface. A trench is formed on the silicon surface and a polymer waveguide having three 45 degree reflectors is patterned in the trench. The trench has two slanted side walls opposite to each other. Two reflectors of the polymer waveguide are arranged on the two slanted side walls. An intrusion structure with a slanted front wall is located in the middle of the waveguide and the third reflector is formed on the slanted front wall. The first reflector receives an optical input source, the second reflector is aligned to return light to the end optical receiver. The third reflector functions as a light splitter and is aligned to an intermediate optical receiver. Light splitting ratio is determined by the third reflector size relative to the waveguide cross section near the third reflector. A fabrication method is disclosed thereof.

Abstract: A photonic neural component includes optical transmitters, optical receivers, inter-node waveguides formed on a board, transmitting waveguides configured to receive optical signals emitted from the optical transmitters and transmit the received optical signals to the inter-node waveguides, mirrors to partially reflect optical signals propagating on the inter-node waveguides, receiving waveguides configured to receive reflected optical signals produced by the mirrors and transmit the reflected optical signals to the optical receivers, and filters configured to apply weights to the reflected optical signals. The transmitting waveguides and receiving waveguides are formed on the board such that one of the transmitting waveguides and one of the receiving waveguides crosses one of the inter-node waveguides with a core of one of the crossing waveguides passing through a core or clad of the other.

Abstract: A wavelength tunable light source has a light source, a wavelength monitor circuit that receives a portion of light emitted from the light source, and a processor that controls a wavelength of the light emitted from the light source based upon an output value of the wavelength monitor circuit, wherein the wavelength monitor circuit has a wavelength filter that outputs four light components with optical phases shifted by 90 degrees from one another and multiple photo detectors that detects the four light components output from the wavelength filter, and wherein the processor selects at least one of the four light components, calculates a ratio of a monitor value of the selected light component to a total sum of monitor values of the four light components, and adjusts the wavelength of the light source so as to bring the ratio to be closer to a target ratio at a designated wavelength.

Abstract: A transimpedance amplifier connectable to a light receiving element includes a bias terminal for suppling bias potential to the light receiving element, an input terminal to receive a signal from the light receiving element and a ground terminal. The bias terminal, the input terminal and the ground terminal are arranged on at one side of the transimpedance amplifier facing the light receiving element.

Abstract: Systems and methods for generating radio frequency signals and/or microwave signals using a tunable optical source. An optical frequency comb including multiple optical components is received or generated based on an optical signal. A subset of optical components is selected from the multiple optical components. A detector array having two or more square law detectors is uniformly illuminated with the subset of optical components. Each square law detector of the detector array outputs an electrical signal having a difference frequency corresponding to a difference in frequency between the subset of optical components. A radio frequency or microwave output signal with a narrow bandwidth centered at a target frequency is generated by coherently summing each of the output signals output by the square law detectors.

Abstract: An optical modulator including a flexible printed circuit performing an electrical connection with an external circuit substrate, in which the flexible printed circuit includes a plurality of first pads and the like provided on one surface of the flexible printed circuit along one side of the flexible printed circuit, a plurality of second pads and the like provided on the other surface of the flexible printed circuit at locations that respectively correspond to the plurality of first pads, and a plurality of metal films and the like provided at locations that respectively correspond to the first pads on a side surface of the flexible printed circuit along the one side of the flexible printed circuit.

Abstract: The disclosed embodiments relate to a system that implements a hybrid laser. This system includes a reflective gain medium (RGM) comprising an optical gain material coupled to a mirror. This RGM is coupled to a spot-size converter (SSC), which optically couples the RGM to an optical reflector through a silicon waveguide. The SSC converts an optical mode-field size of the RGM to an optical mode-field size of the silicon waveguide. During operation, the RGM, the spot-size converter, the silicon waveguide and the silicon mirror collectively form a lasing cavity, wherein an effective thermo-optic coefficient (TOC) of a portion of the lasing cavity that passes through the optical gain material and the SSC material is substantially the same as the TOC of silicon. Finally, a laser output is optically coupled out of the lasing cavity.

Abstract: An optical receiver module includes a substrate, photodetectors mounted on a first surface of the substrate, amplifiers mounted on the first surface of the substrate, anode wiring patterns formed on the first surface of the substrate and configured to connect between anode terminals of the photodetectors and respective ones of the amplifiers, cathode wiring patterns formed on the first surface of the substrate and configured to connect between cathode terminals of the photodetectors and the respective ones of the amplifiers, a second electrode formed on a second surface of the substrate to cover areas directly opposite, across the substrate, the cathode wiring patterns formed on the first surface, and first vias formed through the substrate in a vicinity of connection points between the cathode wiring patterns and the amplifiers and configured to connect between the cathode wiring patterns and the second electrode.

Abstract: An optical resonator apparatus includes an optical resonator unit wherein ring optical resonators each including a first optical waveguide and a resonance wavelength adjustment electrode are coupled in cascade connection and round-trip lengths of the ring optical waveguides are different from each other and vary in order from an input side to an output side, and a controller that adjusts a resonance wavelength of each ring optical resonator in order beginning with the ring optical resonator provided at the most input side so as to match with an input light wavelength and, when an inter-channel occurs, adjusts the resonance wavelength of the first ring optical resonator from the input side so as to match with a second-matching input light wavelength and adjusts the resonance wavelengths of the second and succeeding ring optical resonators from the input side so as to match with the first-matching input light wavelength.

Abstract: An optical communication device includes a substrate, a photoelectric element for emitting/receiving optical signals, a driver chip for driving the photoelectric, and a light waveguide for transmitting optical signals. The substrate defines a through fixing hole. The photoelectric element and the driver chip are electrically connected to the substrate. The photoelectric element includes a base portion and an optical portion formed on the base portion. The optical portion includes an optical surface serving as a light emergent/incident surface, the optical surface faces toward the substrate, and the optical portion is aligned with the fixing hole. An end of the light waveguide is inserted and fixed into the fixing hole and is optically aligned with the optical portion.

Abstract: An optical device includes a gain medium on a substrate. The device also includes one or more laser cavities and an amplifier on the substrate. The one or more laser cavities each guides a light signal through a different region of the gain medium such that each of the light signals is amplified within the gain medium. The amplifier guides an amplified light signal through the gain medium such that the amplified light signal is amplified in the gain medium.

Abstract: Techniques relating to optical communications are illustrated. In an example, a system for optical communications includes a laser emitting device including an emission surface for emission of a laser beam. An optical waveguide may be optically coupled to the laser emitting device to receive the laser beam from the laser emitting device. A fault photo-detector surrounds the emission surface. The fault photo-detector is to detect a portion of the laser beam accidentally back-reflected towards the laser emitting device.

Abstract: A photonic integrated circuit (PIC) is described. This PIC includes a semiconductor-barrier layer-semiconductor diode in an optical waveguide that conveys an optical signal, where the barrier layer is an oxide or a high-k material. Moreover, semiconductor layers in the semiconductor-barrier layer-semiconductor diode may include geometric features (such as a periodic pattern of holes or trenches) that create a lattice-shifted photonic crystal optical waveguide having a group velocity of light that is lower than the group velocity of light in the first semiconductor layer and the second semiconductor layer without the geometric features. The optical waveguide is included in an optical modulator, such as a Mach-Zehnder interferometer (MZI).

Abstract: An optical module includes a waveguide substrate including an optical waveguide and electrodes that apply electronic signals to the optical waveguide; a relay substrate disposed adjacent to the waveguide substrate; a terminal substrate disposed adjacent to the waveguide substrate and opposite to the relay substrate across the waveguide substrate; and a carrier substrate on which the waveguide substrate, the relay substrate, and the terminal substrate are mounted. The electrodes have a first interconnect unit from the relay substrate to the terminal substrate via the waveguide substrate and second interconnect units from the first interconnect unit and branching on the terminal substrate. Among the second interconnect units, a first interconnect branch includes a capacitor and a terminal resistor; and a second interconnect branch is connected to an interconnect of the carrier substrate via a bias resistor, passes under the waveguide substrate to a DC electrode for bias-adjusting on the relay substrate.

Abstract: An optical communication system, a transmitter, a receiver, and methods of operating the same are provided. In particular, a transmitter is disclosed as being configured to encode optical signals in accordance with a multi-level coding scheme. The receiver is configured to provide receive and decode to the optical signals received from the transmitter. One or both of the receiver and transmitter are configured to compensate for non-idealities or non-linearities introduced into the communication system by optical components of the system.

Abstract: A method for enabling the transmission of power between two mutually rotating members without the use of wires or heavy inductive bundles has been invented in which the electrical signal is first converted an electro-magnetic wave, such as an optical or infrared beam, then transmit across the rotational interface using a fiber optic rotation joint, or similar device, and then finally converting that beam back into electrical power.

Abstract: The methods, systems, and apparatuses described in this disclosure enable the use of pluggable optics such that two outgoing connections or two incoming connections can support the use of dual transmitter optics and/or dual receiver optics. The forward and/or reverse capacity of an optical network can be doubled using two transmitters and/or receivers operating in parallel. In embodiments, forward and/or reverse capacity of an optical network can be doubled using a double capacity transmitter or receiver that is operable to combine two or more electrical signals into a single optical signal. A pluggable can support two transmitting or two receiving optical links, and can also support a double capacity transmitting or receiving optical link.

Abstract: An optical communication fiber includes: a fiber body having a tip surface; and a light absorption layer provided to the tip surface of the fiber body, and configured to reduce light transmittance of communication light.

Abstract: High-security communications against information leakage as well as high-speed communications are realized using present optical fiber networks. The methods are as follows: (1) A seed key is shared between a transmitter and a receiver in advance. Random numbers are transmitted using carrier light accompanied by fluctuations and bases that are decided by random numbers. The transmitter and receiver compare a shared basis that is determined by the seed key with the random basis, and decompose the random numbers superimposed on each bit into two sequences, based on whether the shared basis coincides with the random basis or not. Error correction is processed for each sequence in the receiver, and then the random numbers are shared between the transmitter and the receiver. (2) The amount of the random numbers shared between the transmitter and the receiver is reduced to secret capacity through privacy amplification, and the resultant random numbers are used as a secret key.

Abstract: Embodiments of the present disclosure provide a laser diode. The laser diode includes: a semiconductor substrate, a waveguide layer and a light wave limiting layer. The waveguide layer is disposed on the semiconductor substrate, and comprises a quantum well layer. The light wave limiting layer is disposed on a surface of the waveguide layer, and is configured to limit a light wave to be transmitted in the waveguide layer. The quantum well layer includes a plurality of quantum well regions that are disposed along a transmission direction of the light wave, and the quantum well regions respectively have gain peaks of different wavelengths. The embodiments of the present disclosure further provide a manufacturing method of a laser diode and a passive optical network system using the laser diode.

Abstract: The I phase modulator modulates a phase based on the bias voltage in which a first modulation signal and a first pilot signal are inherent and the Q phase modulator modulates a phase based on the bias voltage in which a second pilot signal different from the first pilot signal and a second modulation signal are inherent. A time-average power synchronous detection unit detects an optical power at a timing at which the positivity and negativity of the voltages of both pilot signals become the same, and an optical power when the positivity and negativity of the voltages of both pilot signals are opposite. The bias voltage control unit controls the bias voltage so that the difference between both the optical powers becomes small based on the detection result of the time-average power synchronous detection unit.

Abstract: There is provided an optical receiver. The optical receiver includes a board to be coupled with an optical transmission line array, an optical diode array disposed on the board, and the optical diode array including a plurality of photo diodes each of which receives light from a corresponding optical transmission line in the optical transmission array. Further bias suppliers, conversion circuits, and capacitors are provided on the board or a real side of the board. Each of the photo diodes includes a first electrode and second electrodes, the first electrode receives a bias voltage supplied by a bias supplier, a current signal flowing through the second electrode is converted by a conversion circuit into a voltage signal, and one end of a capacitor is coupled to the first electrode and the other is grounded.

Abstract: An optical transmitter includes: a ring waveguide; an electrode which is formed near the ring waveguide and is provided with a signal; a first waveguide optically coupled to the ring waveguide; a second waveguide optically coupled to the ring waveguide without optically coupled directly to the first waveguide; and a light source configured to supply continuous wave light to the first waveguide.

Abstract: Example systems, apparatus, circuits, and other embodiments described herein concern acquiring telemetry data from an MR system and providing the telemetry data via fiber optic cable. One example apparatus includes a telemetry signal acquisition element (e.g., circuit, circuit component) that is configured to acquire a telemetry signal from a component in the MR apparatus. The component may be, for example, a transmit coil or an on-coil amplifier. The example apparatus also includes a fiber optic cable that is configured to carry an output signal from the MR apparatus through a field produced by the MR apparatus. The example apparatus also includes a telemetry signal output element that is configured to produce the output signal from the telemetry signal and to transmit the output signal via the fiber optic cable.

Abstract: A communications device includes a transmitter device having an optical source configured to generate an optical carrier signal, a first E/O modulator coupled to the optical source and configured to modulate the optical carrier signal with an input signal having a first frequency, and a second E/O modulator coupled to the optical source and configured to modulate the optical carrier signal with a reference signal. The communications device includes an optical waveguide coupled to the transmitter device, and a receiver device coupled to the optical waveguide and including an O/E converter coupled to the optical waveguide and configured to generate an output signal comprising a replica of the input signal at a second frequency based upon the reference signal.

Abstract: An optical fiber transmission system includes a light emitting source, a plurality of light receiving terminals, and a plurality of optical fibers connecting the light emitting source to the light receiving terminals. The optical fiber transmission system further includes a plurality of controlling modules positioned between the light receiving terminals and the optical fibers. Each of the plurality of controlling modules includes a controller, a signal analyzer, and a reflective member. The signal analyzer and the reflective member are connected to the controller and analyze and reflect optical signals respectively.

Abstract: Data security of a multi-dimensional code system is increased. An optical device is provided with a single input port; a splitter splitting an input light from the input port into a plurality of lights; a plurality of phase shifters each shifting one of the lights split by the splitter; a multi-port encoder/decoder inputting the lights whose phases are shifted by the phase shifters and generating spectral encoded codes; and a plurality of output ports outputting the spectral encoded codes generated by the multi-port encoder/decoder.

Abstract: A polarization controller includes a first polarization controller, a demultiplexer, a second polarization controller, and a multiplexer. The first polarization controller controls the state of polarization of input light such that a part of the wavelength components of the input light is in a first state of polarization. The demultiplexer demultiplexes the light output from the first polarization controller into a plurality of wavelength components. The second polarization controller controls the plurality of wavelength components in a second state of polarization by using liquid crystal modulation devices. The multiplexer multiplexes the plurality of wavelength components output from the second polarization controller.

Abstract: Embodiments of the invention provide apparatuses and methods for phase correlated seeding of parametric mixer and for generating coherent frequency combs. The parametric mixer may use two phase-correlated optical waves with different carrier frequencies to generate new optical waves centered at frequencies differing from the input waves, while retaining the input wave coherent properties. In the case when parametric mixer is used to generate frequency combs with small frequency pitch, the phase correlation of the input (seed) waves can be achieved by electro-optical modulator and a single master laser. In the case when frequency comb possessing a frequency pitch that is larger than frequency modulation that can be affected by electro-optic modulator, the phase correlation of the input (seed) waves is achieved by combined use of an electro-optical modulator and injection locking to a single or multiple slave lasers.

Abstract: Provided is an optical module. The optical module includes: an optical bench having a first trench of a first depth and a second trench of a second depth that is less than the first depth; a lens in the first trench of the optical bench; at least one semiconductor chip in the second trench of the optical bench; and a flexible printed circuit board covering an upper surface of the optical bench except for the first and second trenches, wherein the optical bench is a metal optical bench or a silicon optical bench.

Abstract: A method and apparatus for transporting multiple low-speed data streams across a high-speed communication channel or link. In one embodiment of the method, first and second data streams are transmitted at first and second data transmission rates, respectively, via an optical cable, wherein the first and second data transmission rates are distinct. Components of the first data stream are transmitted via the optical cable between transmission of components of the second data stream via the optical cable, and components of the second data stream are transmitted via the optical cable between transmission of components of the first data stream via the optical cable.

Abstract: An optical modulator includes a Mach-Zehnder optical waveguide that includes a pair of parallel waveguides, and a two-input-one-output optical coupler that couples light output from the parallel waveguides; a branching waveguide that branches a portion of light output from the optical coupler; and a light receiving unit that receives the light output from the branching waveguide. Orientation of an output end of the branching waveguide is angled toward the light receiving unit, to be oblique with respect to the parallel waveguides, and orientation of an output end of the optical coupler is angled toward a side opposite to that of the output end of the branching waveguide, to be oblique with respect to the parallel waveguides.

Abstract: In one embodiment, the optical transmitter is configured to generate a plurality of optical signals at a corresponding plurality of different wavelengths multiplexed onto an output waveguide. The transmitter includes a first and second converter including different first and second active materials configured to emit light at a first and a different second wavelength, respectively. Furthermore, the transmitter includes a first converter waveguide traversing the first and second material of the first and second converters. The second material is at an output end of the first converter waveguide and the first material is at an input end, upstream of the output end, of the first converter waveguide. The second active material is transparent to the light at the first wavelength and the output end of the first converter waveguide leads to the output waveguide.

Abstract: An optical engine for providing a point-to-point optical communications link between a first computing device and a second computing device. The optical engine includes a modulated hybrid micro-ring laser formed on a substrate and configured to generate an optical signal traveling parallel to the plane of the substrate. The optical engine further includes a waveguide, also formed in a plane parallel to the plane of the substrate, that is configured to guide the optical signal from the modulated ring laser to a defined region, a waveguide coupler at the defined region configured for coupling the optical signal into a multi-core optical fiber, and a multi-core optical fiber at the defined region that is configured to receive and transport the optical signal to the second computing device.

Abstract: Methods and apparatus for optical analog to digital conversion are disclosed. An optical signal is converted by mapping the optical analog signal onto a wavelength modulated optical beam, passing the mapped beam through interferometers to generate analog bit representation signals, and converting the analog bit representation signals into an optical digital signal. A photodiode receives an optical analog signal, a wavelength modulated laser coupled to the photodiode maps the optical analog signal to a wavelength modulated optical beam, interferometers produce an analog bit representation signal from the mapped wavelength modulated optical beam, and sample and threshold circuits corresponding to the interferometers produce a digital bit signal from the analog bit representation signal.

Abstract: Systems and methods for reducing modal group delay when transmitting a plurality of optical signals over a transmission line that supports a plurality of modes are disclosed. The modes are converted at a plurality of positions along the transmission line so the signals in the end have minimal group delay. The method comprises the steps of receiving N number of optical signals into a multimode fiber having at least N modes, transmitting each of N signals into a mode of the at least N modes of the multimode fiber, and converting each of the N modes into another of the N modes at N positions along the transmission line, such that the net modal group delay generated between the N signals along the transmission line is minimized.

Abstract: An optical transmitter for converting an input data series into an optical multi-level signal and for outputting the same, includes an LUT in which data for executing optical multi-level modulation is stored and from which first modulation data and second modulation data are output based on the input data series. A DAC converts the first modulation data by D/A conversion to generate a first multi-level signal. A DAC converts the second modulation data by D/A conversion to generate a second multi-level signal. A dual-electrode MZ modulator includes a first phase modulator for modulating light from a light source in accordance with the first multi-level signal and a second phase modulator for modulating light from the light source in accordance with the second multi-level signal, and combines an optical signal from the first phase modulator and an optical signal from the second phase modulator to output the optical multi-level signal.

Abstract: Systems and methods are provided for modulating, channels in dense wavelength division multiplexing (“DWDM”) systems. In one aspect, a modulation and wavelength division multiplexing system includes a channel source and a waveguide tree structure disposed on a substrate. The tree structure includes waveguides branching from a root waveguide. The waveguides include two or more terminus waveguides coupled to the channel source. The system also includes one or more modulator arrays disposed on the substrate. Each modulator array is optically coupled to one of the two or more terminus waveguides and is configured to modulate channels injected into a terminus waveguide from the channel source to produce corresponding optical signals that propagate from the terminus waveguide along one or more of the waveguides to the root waveguide.

Abstract: An optical system including an array of photonic devices that convert light signals to electrical signals or electrical signals to light signals are coupled together and optically coupled to an array of optic fibers of an information channel. A lens couples optical beams generated to at least one array of photonic devices and the array of optic fibers for an optical communication there-between. The array of photonic devices and the array of optic fibers are respectively arranged in a honeycomb configuration.

Abstract: Example method, apparatus, and system embodiments are disclosed to provide a high data throughput optical communication link. An example embodiment comprises: a high frequency optical receiver configured to receive signals modulated with high frequency data; an optical waveguide having a receiving portion and a transmitting portion juxtaposed with the receiver, configured to transfer signals incident on the receiving portion, to the transmitting portion, and to transmit the signals to the receiver; a guide portion configured to releasably engage another apparatus, for positioning the waveguide with respect to the other apparatus, to receive at the receiving portion of the waveguide, signals from the other apparatus, for delivery to the receiver; and a wireless power circuit configured to exchange wireless power with the other apparatus, to convert between electrical signals modulated with high frequency data and the optical signals modulated with high frequency data received by the waveguide.

Abstract: A reconfigurable polarity detachable connector assembly includes a housing defining two accommodation channels and providing a springy protruding member at a top side, two mating simplex connectors respectively detachably mounted in the accommodation channels of the housing, a fiber optic cable fastened to the housing with two optical fiber cores thereof respectively inserted into respective calibration support rods of the mating simplex connectors, and a sliding cap slidably coupled to the housing. The sliding cap is unlocked and can be moved backwardly relative to the housing to expose the optical fiber cores of the fiber optic cable to the outside of the housing for allowing position exchange between the two mating simplex connectors after the user presses the springy protruding member.

Abstract: An apparatus includes an all-optical transmission line having, at one wavelength, a pair of relatively orthogonal optical propagating modes whose local group velocities differ along a part of the all-optical transmission line. The all-optical transmission line is formed by a sequence of optically end-connected multi-mode fiber segments. The segments include, at least, 80% of the optical path length of the all-optical transmission line. Each segment is configured such that a differential group delay between the pair varies monotonically there along and changes by, at least, 200 pico-seconds thereon.

Abstract: A photoelectric encoder includes a scale; a detector; alight application section; a pair of origin signal reception sections; and a signal processing section adapted to provide the maximum value of the signal level output from the origin signal reception sections by side lobe light occurring as reflected on the origin mark as a stipulated value, provide an effective area of origin detection between the first position at which output of one of the origin signal reception sections for outputting a larger signal level than the stipulated value earlier than the relative displacement becomes a larger signal level than the stipulated value and the first position at which output of the other origin signal reception section exceeds the stipulated value and then becomes a smaller signal level than the stipulated value, and configured to generate the origin detection signal in the effective area.

Abstract: A system and methods are provided for converting a first temporally short and spectrally broad optical pulse into a train of spectrally narrow and distinct optical pulses. This involves receiving, on a first I/O channel, the first optical pulse associated with a plurality of wavelengths and performing wavelength division demultiplexing on the first optical pulse at an optical unit housed on an optical chip to output a plurality of second optical pulses on different ones of a plurality of second I/O channels, each of the second optical pulses associated with a unique wavelength range from the first optical pulse. This also involves receiving the second optical pulses at loop mirrors in the second I/O channels, wherein the second I/O channels are patterned as waveguides in the optical chip and reflecting, at the loop mirrors, the second optical pulses back to the optical unit.

Abstract: Provided is a multi-wavelength optical source generator. The multi-wavelength optical source generator includes: a gain part generating a plurality of lights through a plurality of gain waveguides; a reflective part transmitting or reflecting lights provided from each of the plurality of gain waveguides according to a wavelength; and a multiplexing part multiplexing a plurality of lights transmitted and outputted through the reflective part.