Abstract: The main power source unit of an image read-out device supplies power to an laser diode (LD) power supply unit of an electronic cassette through a contact. The LD power supply unit supplies the supplied power to a laser diode (LD), as power used for emitting laser light, and also supplies a portion of the supplied power to an LD power supply unit of the image read-out device through a contact. The power supplied to the LD power supply unit of the image read-out device is supplied as power for emitting laser light to an LD of the image read-out device. When there is a change in the relative position of the casings of the electronic cassette and the image read-out device, the contact and electrical continuation of the contacts breaks and laser light stops being emitted from the LDs.

Abstract: Methods and systems for splitting an initiated signal are disclosed. An exemplary system may include a transmitter configured to selectively transmit an initiated signal, and a signal splitter in communication with the transmitter. The signal splitter may be configured to selectively split the initiated signal into a plurality of recipient signals for a plurality of recipient lines in communication with the transmitter. The signal splitter may be configured to selectively modify a number of recipient signals, e.g., by adjusting a spot size of the initiated signal on the signal splitter.

Abstract: In one embodiment, a gain medium for an external cavity diode laser (ECDL) includes a gain section to provide a gain operation on optical energy in the ECDL that is controlled by a first electrical signal, a semiconductor optical amplifier (SOA) section disposed adjacent to the gain section to amplify the gained optical energy responsive to a second electrical signal, and a trench disposed between the gain section and the SOA section to act as an integrated mirror. Other embodiments are described and claimed.

Abstract: A tunable photonic channelizer includes an optical signal generator and an optical modulator. The optical modulator receives a first optical signal as an input from the optical signal generator and modulates the first optical signal to create a second optical signal. The tunable photonic channelizer includes an optical filter that is selectively tunable. The optical filter receives the second optical signal, filters the second optical signal, provides a third optical signal as a filtered version of the second optical signal. The tunable photonic channelizer includes a feedback loop between the optical filter and the optical signal generator to provide temperature and/or environmental feedback from the optical filter to the optical signal generator to enable the first optical signal to float in relation to the temperature and/or environmental feedback.

Abstract: An optical signal generator includes a splitter, a first modulator, a second modulator, a signal-switching unit and a multiplexer. The splitter splits an optical pulse train into a first pulse train and a second pulse train. The first modulator receives the first pulse train and first data signal, and generates a first modulation signal by performing on-off-keying or phase modulation on the first pulse train based on the strength of the first data signal. The second modulator receives the second pulse train and second data signal, and generates a second modulation signal by performing the on-off-keying or phase modulation on the second pulse train based on the strength of the second data signal. The signal-switching unit delays pulses of the second modulation signal or adjusts a phase of a carrier included in the second modulation signal according to a switching signal. The multiplexer generates an optical modulation signal by multiplexing the first modulation signal and the second modulation signal.

Abstract: The optical modulator comprises an optical branching unit branching incident light into a first signal light and a second signal light; a first Mach-Zehnder modulator modulating the first signal light; a second Mach-Zehnder modulator modulating the second signal light; a phase shifter giving a fixed phase shift to the phase of the output light from the second Mach-Zehnder modulator; and an optical multiplexer multiplexing the output light from the first Mach-Zehnder modulator and the output light from the phase shifter. The phase shifter gives the phase shift so that the two input lights to the optical multiplexer have a phase difference of 60 degrees, and the first and second Mach-Zehnder modulators are driven by three-level signals.

Abstract: Apparatus and methods for driving a transmitter to generate DNPSK signals is disclosed including generating N data streams comprising data symbols and for each of a plurality of sets of N simultaneous data symbols of the N data streams, imposing signals are on L of a plurality of signal lines, with the value of L corresponding to values of the N simultaneous data symbols. Signals on the plurality of signal lines are ANDed with a clock signal synchronized with the N data streams to produce RZ signals. The RZ signals are summed and the summed signal is input to a laser that produces an output having frequency modulation corresponding to the magnitude of the summed signal. The output of the laser is passed through an optical discriminator.

Abstract: It is expected to provide an optical communication module that does not require making a conductive plate, such as a leadframe, become thinner in response to the downsizing of the photoelectric conversion device, such as a laser diode or a photodiode, and does not require downsizing a lens. A laser diode is connected and fixed to a conductive plate on the top surface of a transparent light-passing board. The light-passing board is connected and fixed to a conductive plate on the top surface of a transparent base. A first lens and a second lens are integrally formed on the top and the bottom surfaces of the base, respectively. The laser diode performs transmission of optical signals through the gap of conductive plate, the transparent light-passing board, the opening portion of a conductive plate, the opening portion of conductive plate, the first lens, the transparent base and the second lens.

Abstract: An integrated semiconductor laser element includes: semiconductor lasers that oscillate at different oscillation wavelengths from one another, each laser oscillating in a single mode; an optical coupler; and a semiconductor optical amplifier. At least one of active layers of the semiconductor lasers and an active layer of the semiconductor optical amplifier have a same thickness and a same composition that is set to have a gain peak wavelength near a center of a wavelength band formed by the oscillation wavelengths. The semiconductor optical amplifier includes: an equal width portion formed on a side of the optical coupler to guide light in a single mode; and an expanded width portion formed on a light output side. The width of the expanded width portion is set according to a total thickness of well layers of the active layer of the semiconductor optical amplifier.

Abstract: Data is encrypted onto an electromagnetic beam by providing an electromagnetic beam having a signal component having a modal state, wherein the signal component is susceptible to accumulation of a geometric phase, and a reference component, transmitted along a path over at least part of which the signal component accumulates a geometric phase by transformation of its modal state from a first to a second modal state, from the second to at least one further modal state, and then back to the first modal state; and modulating with the data the geometric phase so accumulated, by modulating the modal state transformations. Data is decrypted from a received electromagnetic beam by corresponding processing of the received electromagnetic beam and by comparing an overall phase of the signal component with an overall phase of the reference component so as to retrieve the modulation.

Abstract: Equipped between a transmitter 20 and an optical multiplexer module 25 of a division/multiplexer unit 24 are band-pass filters 23-1 through 23-m letting only a light of right wavelength pass while reflecting other wavelengths light. The transmitter 20 is equipped with a reflection light monitor 26 for monitoring a reflection light from the band-pass filters 23-1 through 23-m for examining an intensity of a reflection light. A wavelength of a light oscillated by a tunable laser diode (LD) unit 21 is controlled so as to make the intensity of the light smaller than a threshold value.

Abstract: An optical transceiver device including a modulating assembly. In contrast with conventional transceivers, the optical transceiver device uses a modulating assembly rather than a laser. The modulating assembly is located within the transceiver itself and includes first and second collimating lenses, first and second mirrors, and a p-i-n diode. An optical signal that has not yet been modulated is introduced into the modulating assembly via the first collimating lens, and is redirected toward the p-i-n diode via the first mirror. Depending on the voltage state of the diode, the light signal is either transmitted through the diode or prevented from passing, which results in modulation of the signal for data transmission. The modulated signal passes through the modulating assembly and is reflected by the second mirror toward the second collimating lens, through which it passes before exiting the transceiver.

Abstract: Rhomb beam splitters are used to implement various optical demodulators, in particular PSK and DPSK demodulators. The parallel beam-splitting and reflective surfaces of the rhomb structure produce reflection and transmission beams that exit the beam splitter parallel to one another and with a relative phase shift determined by the distance between the surfaces. These features afford the advantages of low cost, compactness, easily tunable, and temperature-insensitive optical structures for constructing a variety of optical demodulators.

Abstract: An LD-Driver with the push-pull arrangement is disclosed. The driver includes the high side driver driven by the positive phase signal and the low side driver driven by the negative phase signal. When the positive phase signal is in HIGH, the high side driver becomes ON and the LD driver provides additional current to the bias current for the LD; while, when the negative phase signal is in HIGH, the low side driver becomes ON and the LD driver extracts a portion of the bias current for the LD.

Abstract: The present invention relates to a data transmission optical device including a source emitting a laser beam for transmitting the data toward an optical sensor. The device has means for collimating the beam. It may be implemented on board an aircraft for transmitting audio or video data to the passenger seats. The device has applications for on-demand video.

Abstract: The present invention provides an optical power level discriminating device and method for discriminating optical power levels. The optical discriminating device includes a splitter for receiving an optical signal having first and second signal states, and splitting the received optical signal into a first and a second branch optical signal. A first optical fiber for transporting the first branch optical signal is provided that is made of a material having a high non-linear refractive index providing a different non-linear phase shift to the first and second signal states of the first branch optical signal. A second optical fiber is provided for transporting the second branch optical signal with little or no non-linear effect. The discriminating device also includes a combiner for combining the first branch optical signal and second branch optical signal to produce an output optical signal.

Abstract: A demodulator includes a splitter, a first dielectric substance, and a combiner. The splitter splits a differential phase shift keying optical signal into a first light beam and a second light beam and outputs the first light beam to a first optical path and the second light beam to a second optical path. The first dielectric substance is disposed in the first optical path and has a refractive index higher than the average refractive index of the second optical path. The combiner combines the first light beam and the second light beam and causes the beams to interfere with each other. The difference in length between the first and second optical paths and the refractive index of the first dielectric substance are set such that the first light beam is delayed by one bit with respect to the second light beam.

Abstract: According to one embodiment of the invention, a 16-QAM optical modulator has a Mach-Zehnder modulator (MZM) coupled to a drive circuit that drives the MZM based on two electrical binary signals. The output of the MZM corresponds to an intermediary constellation consisting of four constellation points arranged on a straight line in the corresponding in-phase/quadrature-phase (I-Q) plane. Two of these constellation points correspond to a zero phase, and the remaining two constellation points correspond to a phase of ? radian. The 16-QAM optical modulator further has a phase shifter that modulates the output of the MZM based on two additional electrical binary signals. The resulting optical output signal corresponds to a star 16-QAM constellation, which is produced by incremental rotation of the intermediary constellation.

Abstract: Thermal management of a locker etalon in a transmitter optical subassembly (TOSA). In one example embodiment, a TOSA includes a case, a laser positioned within the case and electro-thermally connected to the case, a locker etalon positioned in the case and thermally connected to the case, and a thermoelectric cooler (TEC) positioned within the case and in thermal contact with both the laser and the locker etalon.

Abstract: A signal Data1 and Data2 are output from a DQPSK signal source. The output signal is input to the modulator drivers 1 and 2 of the differential output. A drive signal is applied from the drivers 1 and 2 to a modulator, and modulated light is output. An optical coupler 20 branches modulator output, and a power monitor 21 detects the power of the branched light. A detection result is transmitted to an amplitude control unit 22. The amplitude control unit 22 adjusts the amplitude of the drivers 1 and 2 such that the detection result of the power monitor 21 can be the maximum.

Abstract: Noise may be received through a microphone included in a lighting apparatus. The noise may then be analyzed to determine if a human being may have been the source of the noise, and a message sent over a network alerting other devices that a human-caused noise was detected.

Abstract: A method includes modulating lightwaves to provide first and second OFDM signal sidebands at a first polarization direction and first and second OFDM signal sidebands at a second polarization direction, and combining sidebands that are oppositely positioned and joined from the first and second OFDM signal sidebands at each polarization direction to provide a polarization multiplexing OFDM signal.

Abstract: A photonic system and method are provided. The system includes an optical source configured to generate a carrier signal; and a modulator configured to modulate the carrier signal with a radio frequency, (“RF”) input signal to generate a modulated signal. The system also includes an optical filter configured to filter the modulated signal to generate a vestigial sideband modulated signal; and an optical detector configured to demodulate the vestigial sideband signal to generate an RF output signal. The system further includes a wavelength controller module configured to set an operating parameter of the optical source.

Abstract: An illuminating light communication device comprises a constant current source, a smoothing capacitor connected to an output of the constant current source, a load circuit comprising a light emitting diode and connected to the output of the constant current source, a load change element added to the load circuit and thereby partially changing load characteristic of the load circuit, and a switch element configured to determine whether or not the load change element is added to the load circuit in accordance with a binary optical communication signal.

Abstract: A driver circuit includes a plurality of delay circuits and an inverter. The plurality of delay circuits delay branched driving signals. The inverter inverts at least one of the branched driving signals. At least one of the plurality of delay circuits is at least one variable delay circuit delaying a variable amount of delay. The output driving signal is output by combining the inverted signal of the branched driving signal output via at least one inverter and at least one non-inverted signal of the branched driving signals output from the delay circuits.

Abstract: A polarization multiplexing and transmitting apparatus generates polarization multiplexed light by multiplexing modulated signal components that having varying intensities and are in polarization states orthogonal to each other. The polarization multiplexing and transmitting apparatus includes a converting unit that converts light generated by a light source into signal components having a varying intensity synchronized with a clock signal input thereto and a varying intensity inversely synchronized with the clock signal, respectively; a modulating unit that modulates the signal components, respectively; and a polarization adjusting unit that orthogonalizes polarization states of the signal components.

Abstract: In an optical transmission module having a communication module which is freely movable in a case, when a tensile force is generated on an optical cable after connection of an optical transmission module, optical coupling surface and an optical axis center follow each other and thus stable optical transmission can be constantly performed.

Abstract: A receiver system comprises an antenna configured to receive an input RF signal, a high spur free dynamic range modulator configured to receive the input RF signal from the antenna and to convert the input RF signal to an optical signal, and a tunable filter configured to receive the optical signal and to output a filtered optical signal. The tunable filter includes at least one electro-optic resonator, at least one electrode configured to supply an electrical control signal to the electro-optic resonator, and a controller configured to adjust the electrical control signal to adjust a refractive index of the electro-optic resonator, whereby a resonant frequency of the electro-optic resonator is selectably adjusted. The receiver system further comprises a receiver configured to receive the filtered optical signal.

Abstract: An apparatus, system and method wherein a polarization multiplexed differential phase shift keying format (POLMUX-DPSK) is provided with offset and bit-interleaved frequency channels and demodulated using a DPSK demodulator.

Abstract: An optical gate switch circuit includes: an asymmetric Mach-Zehnder interferometer having an optical path that outputs control light and probe light to a second optical directional coupler via a first optical directional coupler and an optical phase modulation element, and another optical path that connects a third optical directional coupler to which the probe light is input, to the second optical directional coupler via a variable optical attenuator and an optical phase shifter; and a bandpass filter connected to the second optical directional coupler.

Abstract: The present invention discloses a wavelength-division multiplexing passive optical network (WDM-PON) capable of high-bandwidth transmission for optical signals by using modulation format having high spectral efficiency. The WDM-PON according to the present invention provides a larger capacity and higher bandwidth transmission economically (at lower costs) by using a modulation format where spectral efficiency (a transmission bit number per a unit band width) is high, while using a low noise part of a light source.

Abstract: There is provided a transmission device including an optical signal generation section configured to generate an optical signal formed by arranging one or more of each of a plurality of kinds of same-color light beams each having different phase, and a transmission section configured to transmit the optical signal generated by the optical signal generation section.

Abstract: An optical clock signal recovery apparatus includes a mode-locked semiconductor laser that generates an optical pulse train polarized in a first direction. Optical components of the apparatus transmit a component of an input optical signal polarized in a second direction, perpendicular to the first direction, into the mode-locked semiconductor laser while blocking the component of the input optical signal polarized in the first direction, and transmit light exiting the mode-locked semiconductor laser polarized in the first direction, while blocking light exiting the mode-locked semiconductor laser polarized in the second direction. The transmitted exiting light is output as a recovered optical clock signal.

Abstract: The present invention addresses the problem of transmitting optical signals with high extinction ratios using low-power drive signals. At present, low-power optical transmitters typically operate with modulation extinction ratios of, at best, about 10 dB. Embodiments of the present invention may achieve extinction ratios exceeding 20 dB using low-power drive signals of under 20 mW at data rates on the order of Gbits/sec. In addition, the modulation may be achieved with both low-power and low-fidelity drive waveforms, enabling conventional and often noisy high-speed, low-power electronics to generate high-extinction, high-fidelity optical waveforms.

Abstract: In an optical transmitter comprising a directly modulated laser and a wavelength filter provided on a post-stage of the directly modulated laser, the wavelength filter has a modulated light input port for inputting modulated light output from the directly modulated laser, a filter transmitted light output port for outputting light having a wavelength included in a filter transmission band among the modulated light as filter transmitted light, and a filter cutoff light output port provided separately from the modulated light input port and the filter transmitted light output port and outputting light having a wavelength included in a filter cutoff band among the modulated light as filter cutoff light, and the peak of the filter transmission band is set on a shorter-wave side from the peak of the spectrum of modulated light output from the directly modulated laser.

Abstract: A demodulator and method are provided. The demodulator for demodulating an optical signal, includes a splitter that splits a differential phase modulation signal into a first split light component and a second split light component, couples the first split light component to a first optical path and the second split light component to a second optical path, a first medium disposed on the first optical path, a second medium disposed on the second optical path and having a refractive index different from that of the first medium, and a combiner that combines the first split light component that has passed through the first medium and the second split light component that has passed through the second medium, wherein one of the first split light component and the second split light component is delayed in relation to the other.

Abstract: A method and apparatus for modulating an RF signal. The RF signal is supplied to a grating modulator having a grating, and light of at least a first wavelength is supplied as a first optical carrier to the grating modulator. The first carrier light is modulated by the grating modulator, wherein the first wavelength of the first carrier coincides with a null in the third derivative of a transmittance spectrum of the grating. Optionally, light of at an additional, second wavelength as a second optical carrier, is supplied to the grating modulator which modulates the second carrier light. The second wavelength of the second carrier coincides with another null, but different than the first mentioned null, in the third derivative of a transmittance spectrum of the grating.

Abstract: An optical pulse generator includes a light emitting element that emits an optical pulse, and a driver. The driver is configured to apply a pulse driving current to the light emitting element to allow the light emitting element to emit an optical pulse. The driver is also configured to apply a preliminary driving current to the light emitting element prior to starting the application of the pulse driving current. The preliminary driving current is lower than a minimum level that needs to cause a stimulated emission of light.

Abstract: An optical transmitter which modulates the phases and intensities of double pulses and then transmits them, includes a branching section which branches each of the input double pulses to first and second paths, a first optical modulator placed in the first path, second and third optical modulators placed in series in the second path, and a combining section which combines the double pulses having traveled through the first path with the double pulses having traveled through the second path to output double pulses. A control section controls such that each of the first and second optical modulators performs any one of relative intensity modulation and relative phase modulation on the double pulses passing through, and the third optical modulator performs relative phase modulation on the double pulses passing through.

Abstract: An optical communication module and an optical communication device including the same are provided. For example, a first semiconductor chip on which a laser diode is formed and a second semiconductor chip on which a laser diode driver circuit, etc. for subjecting the laser diode to drive by current are formed are mounted on a package printed circuit board to be close to each other. Temperature detecting means is further formed on the second semiconductor chip (laser diode driver circuit, etc.). The temperature detecting means detects a temperature variation ?T of the first semiconductor chip (laser diode) transmitted via a wiring in the package printed circuit board and controls the magnitude of the driving current of the laser diode driver circuit based on a detection result.

Abstract: The invention relates to an illumination device connectable to an AC voltage source for applying an alternating voltage during a series of time intervals. The illumination device comprises at least a first light source and a second light source, arranged to be connected in series to the AC voltage source, to generate a luminance output in response to the alternating voltage. Selection means are provided configured for selectively applying the alternating voltage over the first light source or the first and second light source. A controller is provided for controlling the selection means in response to a data signal comprising data symbols such that one or more of the data symbols are contained in said luminance output. The invention also relates to a method of embedding one or more data symbols in the luminance output of such an illumination device, an optical receiver and an illumination system.

Abstract: A diffractive coupling element based on a computer-generated hologram is used in an optical coupling system of a transmitter to control the launch of laser light from a laser light source onto an end of an optical fiber. The diffractive coupling element controls the launch of the laser light such that a desired optical intensity distribution pattern is provided that substantially avoids the center and edge refractive index defects contained in the optical fiber.

Abstract: The object of the present invention is to provide a modulated optical signal generator utilizing the mechanism of a multiply optical modulator, and a modulated signal generator capable of outputting millimeter waves and the like utilizing the modulated optical signal generator. The above-mentioned object is solved by a modulated optical signal generator (1) provided with an optical modulator (2), a first optical filter (3), and a second optical filter (4), wherein a frequency of a multiplying optical modulation outputted from the second optical filter (4) is controlled by controlling the frequency of the modulating signal inputted to the optical modulator (2).

Abstract: A rhomb beam splitter, rather than a conventional cube, is used in combination with a mirror reflecting both the reflected and transmitted beams to obtain a delay-line interferometer demodulator with a substantially common path. This significantly reduces the sensitivity of the device to environmental changes and also greatly simplifies the manufacture process. A polarization-insensitive coating or a wave plate, a thermal phase tuner with a micro-heater, and two compensator plates are used in the paths of the beams to balance the optical path lengths and to compensate for polarization and environmental effects.

Abstract: A switchable free-spectral-range mode selector is used to change the free spectral range of a free-space delay-line interferometer. The mode selector consists of a rotatable device with at least one transparent plate selected to produce the desired change in the free spectral range of the delay-line interferometer. The device may be rotated in and out of the free-space optical path of on of the interferometer arms. If used as a DPSK demodulator, the device enables operation at multiple predetermined free spectral ranges. In the preferred embodiment, the demodulator includes a 50/50 beam-splitter cube combined with two cavities. The mode selector consists of a plurality of different transparent slabs attached to a rotatable shaft so that any one of the slabs or none may be inserted in the appropriate optical path to obtain the desired FSR mode of operation.

Abstract: A multiple wavelength signal generation device of the present invention is a multiple wavelength signal generation device having an optical comb generator for obtaining an input light and a group of lights shifted from the input light by predetermined frequencies; and an optical adjusting portion adjusting lights to be inputted to the optical comb generator; wherein the optical comb generator is composed of an optical fiber loop (105) which is provided with an optical SSB modulator (101), an optical amplifier (102) for compensating a conversion loss at the optical SSB modulator, an optical input port (103) for inputting lights from the light source, and an optical output port (104) for outputting lights, and the optical adjusting portion is composed of a phase modulator, an intensity modulator, or a frequency modulator.

Abstract: An electro-absorption modulator integrated with a vertical cavity surface emitting laser (VCSEL). An electro-absorption modulator (EAM) is integrated or grown on a VCSEL. The electro-absorption modulator may be separated from the VCSEL by a semi-insulating or nonconducting layer. Contacts on the EAM can bias the EAM such that light emitted by the VCSEL is selectively absorbed. Thus, the VCSEL can emit a constant wave light that is modulated by the integrated EAM.

Abstract: A small-scale VOA system includes a polarization rotator, a voltage multiplier circuit, and at least one transistor. The polarization rotator can be positioned within a TOSA along the emission axis of a corresponding optical signal source in addition to one or more polarizers. A microcontroller provides a first low voltage control signal to a voltage multiplier to generate a large voltage DC signal which is provided to the transistor. The transistor modulates the large voltage signal with a second control signal from the microcontroller to generate a large voltage AC signal for driving the polarization rotator. The polarization rotation of the polarization rotator can be altered depending on the applied large-voltage AC signal. As a result, the polarization rotator and one or more polarizers can variably attenuate signals emitted by the optical signal source or act as a shutter.

Abstract: A frequency up-conversion system includes an optical splitter, an optical modulator, an optical phase-shifter, and an optical coupler. In one embodiment of the present disclosure, the optical splitter is configured to split an optical wave into a first optical wave and a second optical wave, the optical modulator is configured to modulate the first optical wave to form a modulation wave, the optical phase-shifter is configured to shift the phase of the second optical wave by a predetermined phase to form a shifting wave, and the optical coupler is configured to couple the modulation wave and the shifting wave. In one embodiment of the present disclosure, the optical modulator and the optical phase-shifter are connected in a parallel manner.

Abstract: Systems and methods for encoding information in the topology of superpositions of helical modes of light, and retrieving information from each of the superposed modes individually or in parallel. These methods can be applied to beams of light that already carry information through other channels, such as amplitude modulation or wavelength dispersive multiplexing, enabling such beams to be multiplexed and subsequently demultiplexed. The systems and methods of the present invention increase the number of data channels carried by a factor of the number of superposed helical modes.