Abstract: A mixer-based microwave signal generation device is provided, and the mixer-based microwave signal generation device includes a microwave local oscillator source, a mixer, a first filter, a laser, an electro-optic modulator, an optical signal delayer, a photodetector, a second filter, an amplifier and a passive power divider.

Abstract: Systems and methods for Geiger-mode laser vibrometry are described. An example method for laser vibrometry includes receiving a first time-series of single photon arrivals corresponding to a laser beam reflected from or transmitted through a target, the single photon arrivals including information corresponding to vibrations of the target, each single photon arrival separated in time from another single photon arrival, determining, based on two or more of the single photon arrivals, a discrete time sequence having a binary value, and generating a second time-series by assigning a non-binary value to each of the discrete time points, wherein each of the assigned non-binary values is determined based on a number of discrete time points lacking a photon arrival prior to receiving a photon.

Abstract: An artificial reality system is configured to more accurately and efficiently construct a 3D virtual representation of a real-world environment from a set of 2D images. The system identifies points and/or lines within the images that define a plane along an orientation and then performs a planar sweep along a perpendicular path to identify surfaces in which the plane intersects with multiple points. Points that appear to be in the same plane are “collapsed” into a cohesive plane to conserve processing power by estimating and/or storing parameters for the cohesive plane, rather than all of the individual 3D points. In this way, the system also “averages out” random variation in the planar surface that would otherwise result from random noise in the estimation of the individual 3D points. The system may then generate a 3D map from a constrained alignment of all of the identified planes.

Abstract: Provided is an optical modulating device including a substrate including first and second trenches, a phase modulator in a region of the substrate, the phase modulator including an undoped region provided between the first and the second trenches, and first and a second doped regions which are apart from each other with the undoped region therebetween, wherein the phase modulator is configured to modulate a phase of light traveling through the undoped region based on a first electrical signal applied to the phase modulator, an amplifier including a first doped layer, a quantum well layer, a clad layer, and a second doped layer sequentially on the substrate, the amplifier overlapping at least a portion of the phase modulator and being configured to amplify the light based on a second electrical signal applied to the amplifier, and an insulating layer between the phase modulator and the amplifier.

Abstract: A Fourier domain mode-locked optoelectronic oscillator includes a laser light source, a phase modulator, an optical notch filter, a photodetector, an electrical amplifier and a power divider; wherein the laser light source, the phase modulator, the optical notch filter and the photodetector together form a swept microwave photonic filter. The passband of the swept microwave photonic filter is determined by the difference in wavelength corresponding to the laser light source and the notch positions of the optical notch filter. In the present disclosure, the laser light source, the phase modulator, the optical notch filter, and the photodetector are configured to form a fast swept microwave photonic filter, the sweeping of a passband of the microwave photonic filter is realized by the sweeping of the laser light source or the optical notch filter, and the change in the filter's passband is matched with the latency for delivering a signal in the optoelectronic oscillator loop for one trip.

Abstract: A quantum communications system may include transmitter node, a receiver node, and a quantum communications channel coupling the transmitter node and receiver node. The transmitter node may be configured to co-propagate a first pulse for a quantum state and a second pulse to stabilize the quantum state through the quantum communications channel.

Abstract: Systems and methods for activation in an optical circuit in accordance with embodiments of the invention are illustrated. One embodiment includes an optical activation circuit, wherein the circuit comprises a directional coupler, an optical-to-electrical conversion circuit, a time delay element, a nonlinear signal conditioner, and a phase shifter. The directional coupler receives an optical input and provides a first portion to the optical-to-electrical conversion circuit and a second portion to the time delay element, the time delay element provides a delayed signal to the phase shifter, and the optical-to-electrical conversion circuit converts an optical signal from the directional coupler to an electrical signal used to activate the phase shifter to shift the phase of the delayed signal.

Abstract: A method for synchronizing a timing end application (TEA) in an edge communication network includes (a) receiving, at a first access device, a time stamp from a first TEA communicatively coupled to the first access device, (b) transmitting the time stamp from the first access device to a second access device via communication media of the edge communication network, (c) adjusting the time stamp to account for transit time of the time stamp from the first access device to the second access device, and (d) after adjusting the time stamp, transmitting the time stamp from the second access device to a second TEA communicatively coupled to the second access device.

Abstract: Analog signal processing systems and methods manage polarization in coherent optical receivers to eliminate the need for ultra-fast, power-hungry ADCs and DSPs and that require digitization of the full-bandwidth signal path and result in bulky and expensive circuit designs. Various embodiments an analog polarization correction circuit that implements the equivalent of two matrix operations by combining variable and unity gain amplifiers to align polarizations of input signals to generate a polarization-corrected output signal that is aligned with the polarization frame of reference of a receiver. Various embodiments use BSS to perform polarization control, including electro-optical polarization control, in a feedback loop and operate without the need for a pilot tone or a startup sequence when deducing the polarization state.

Abstract: A method for generating a single-cavity dualcomb or multicomb for laser spectroscopy, the method comprising the steps of providing a laser system comprising a pump source, a gain medium, and a resonator having a spectral filter; spectrally filtering, by the spectral filter, light in the resonator and attenuating, in particular blocking, by the spectral filter, one or more wavelength bands at least one of which being located completely within the gain bandwidth of the laser system such that two or more at least partially separated spectral regions are provided; mode-locking the two or more at least partially separated spectral regions.

Abstract: An optical line terminal includes an optical comb generator, N downlink channels Dk, and N uplink-photodetectors PDk. The optical comb generator is configured to generate a carrier signal having an optical-frequency-comb spectrum and including N optical tones Tk and N optical tones Rk, k={1, 2, . . . , N}. Each of the N downlink channels Dk is optically coupled to the optical comb generator and is configured to generate a respective downlink signal DSk that includes optical tone Tk modulated by downlink data. Each of the N uplink-photodetectors PDk is configured to receive a respective one of a plurality of modulated uplink signals USk, having optical tone Rk as a carrier signal.

Abstract: A system for processing optical signals comprising a reference optical signal transmission structure configured to receive an optical signal at a first input and to provide the optical signal at a first output to a photodetector. A delay optical signal transmission structure configured to receive the optical signal at a second input and to provide a delayed optical signal at a second output to the photodetector. A signal processor configured to receive a first electric signal corresponding to the optical signal and a second electric signal corresponding to the delayed optical signal and to generate an output as a function of the first electric signal and the second electric signal.

Abstract: Analog signal processing systems and methods manage polarization in coherent optical receivers to eliminate the need for ultra-fast, power-hungry ADCs and DSPs and that require digitization of the full-bandwidth signal path and result in bulky and expensive circuit designs. Various embodiments an analog polarization correction circuit that implements the equivalent of two matrix operations by combining variable and unity gain amplifiers to align polarizations of input signals to generate a polarization-corrected output signal that is aligned with the polarization frame of reference of a receiver. Various embodiments use BSS to perform polarization control, including electro-optical polarization control, in a feedback loop and operate without the need for a pilot tone or a startup sequence when deducing the polarization state.

Abstract: A system for transmission of an optical signal, the system including an optical coupler for splitting said signal into a first copy and a second copy. The optical coupler has an input for receiving the optical signal, a first output for the first copy and a second output for the second copy. The system also includes a first optical guide connected to the first output, a second optical guide connected to the second output and a superposition module for coherently superimposing the first copy and the second copy of the signal.

Abstract: A communication system comprising n transmitters and a receiver, where n is an integer of at least 2, each of said n transmitters comprising a light source and an encoder such that each transmitter is adapted to output an encoded pulse of light, said receiver comprising a first element, the system further comprising a timing circuit, the timing circuit being configured to synchronize the encoded pulses output by the transmitters such that interference between a light pulse sent from the first transmitter and a light pulse from the second transmitter, interfere at the first element, each transmitter further comprising a suppressing element adapted to stop light exiting one of the transmitters such that the system is switchable between a first operation mode where two transmitters output encoded pulses and where both pulses interfere at the interference element and a second mode of operation where just one transmitter transmits light pulses to said receiver, the suppressing element being controlled to stop ligh

Abstract: Photonic devices for generating linearly frequency modulated arbitrary microwave signals comprise a laser, and assembly for forming the emitted signal and a photoreceiver the passband of which is in the domain of the microwave frequencies. The forming assembly comprises: a first beam splitter; a first optical channel including a frequency-shifting loop comprising a beam splitter, a first optical amplifier, an optical isolator, a first spectral optical filter and an acousto-optical frequency shifter; a second optical channel including an electro-optical frequency shifter; a second beam splitter; a second optical amplifier; and a second optical filter; the acousto-optical frequency shift, the electro-optical frequency shift and the amplification gain of the first optical amplifier being adjustable.

Abstract: Systems and methods therefor relating generally to electro-absorption modulation are disclosed. In a system thereof, a waveguide is for propagating an optical signal. A segmented electro-absorption modulator (“SEAM”) includes: a segmented anode having at least two anode segments spaced apart from one another alongside a first side of the waveguide; and a segmented cathode having at least two cathode segments spaced apart from one another alongside a second side of the waveguide corresponding to the at least two anode segments.

Abstract: A signal generator includes an optical pulse source to provide a plurality of optical pulses; a photosensitive element configured to receive optical pulses and to produce an electrical signal from optical pulses 6, electrical signal 10 including a spectrum that includes a plurality of discrete frequencies that occur at a repetition rate corresponding to that of the optical pulses or a harmonic thereof; a frequency selector to receive the electrical signal from the photosensitive element, to select dynamically the harmonic from the electrical signal and to communicate the dynamically selected harmonic; a direct digital synthesizer (DDS) to receive the harmonic of the electrical signal from the frequency selector and to produce a first output; and a frequency converter to receive the harmonic from the frequency selector and the first output from the DDS, wherein the frequency converter shifts a frequency of the harmonic by an amount substantially equal to a frequency of the first output from the DDS to produce

Abstract: A measuring apparatus includes a light source unit configured to generate probe light, a bifurcating unit configured to cause Brillouin backscattered light occurring from the probe light to bifurcate into first light, which propagates through a first optical path, and second light, which propagates through a second optical path, a delay unit configured to delay one of the first light and the second light, an optical multiplexer configured to multiplex the first light and the second light to generate multiplexed light, and a coherent detector configured to perform homodyne detection of the multiplexed light and to output a difference frequency obtained as a result of the detection as a phase-difference signal.

Abstract: In a PON system in which plural kinds of modulation schemes coexist, when uplink burst signals from respective ONUs are received, the receiving efficiency degrades as the number of the times of switching of the modulation scheme increases. In an optical access (PON) system supporting plural kinds of modulation schemes, an OLT allocates bandwidths for uplink signals, i.e., transmission timings each including a transmission start time and a transmission duration, to ONUs, respectively, such that the bandwidths allocated to plural ONUs for the same modulation scheme are as successive as possible. Based on the transmission timings allocated to the respective ONUs, the OLT switches the modulation scheme of a modulation-scheme variable burst-mode optical transmitter/receiver by control of a modulation scheme controller.

Abstract: The invention relates to a device for measuring the profile of a single pulse or a pulse with a very low repetition rate, comprising replication means (100,105,120,125,130) for generating a series of replica pulses of an initial optical pulse (I), with a recurrence period (?); means (100b,150) for extracting said replica pulses; optical sampling means (160,161) for sampling the extracted replica pulses (Ri) to output optical samples (Ei) from the extracted replica pulses (Ri) with a sampling period (Te), the deviation between the sampling period and the recurrence period being chosen to be not equal to zero and very much less than the recurrence period; detection means (180) for obtaining an electrical signal from optical samples (Ei) output by said optical sampling means (160,161); said replication means comprising parametric amplification means (120,140,141,142) for amplifying said replica pulses.

Abstract: Provided is a method of measuring signal transmission time difference of a measuring device. The measuring device according to embodiments, by measuring a skew on two optical paths through signal delays of sufficient sizes for skew measurement on the optical paths, even a skew having a minute size can be measured within a measurable range.

Abstract: An optical transmission system includes at least a first optical link to transmit a first data signal as a part of a multi-lane signal and a second optical link to transmit a second data signal as another part of the multi-lane signal; on the transmission side, a reference clock is constantly applied to the first data signal of the first optical link, and a delay clock is applied to the second data signal responsive to a control signal on the second optical link; on the receiving side, the phase of a first clock signal detected from the first data signal received on the first optical link and the phase of a second clock signal detected from the second data signal received on the second optical link are compared, and the control signal is detected from the comparison result.

Abstract: Disclosed are a forward discrete/inverse-discrete Fourier transform device and method for optical orthogonal frequency division multiplexing (OFDM) communication and a transmitting and receiving apparatus. The forward inverse-discrete Fourier transform device includes N 1:N splitters for splitting subcarrier signals received from N inputs corresponding to the number of optical frequencies of subcarriers, a phase shift delay array module for shifting phases of the split signals from the 1:N splitters, N N:1 power couplers for coupling signals output from the phase shift delay array module, a time delay array module for performing time delay on optical OFDM symbols from the N:1 power couplers, and an N:1 power coupler for coupling signals output from the time delay array module.

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 skew correction to the optical signals received from the transmitter by dividing a received signal into separate level-specific components and sampling each of the components with distinct sampling blocks.

Abstract: Methods, systems and devices implement optical tapped delay lines. In one aspect, a device includes an optical tapped delay (TDL) including a wavelength conversion element, and a dispersive element, coupled with the wavelength conversion element, to impose a relative delay to an optical signal. The optical TDL can include a nonlinear element to combine signals in a phase coherent manner. The wavelength conversion element can include an optical nonlinear device such as a periodically poled lithium niobate (PPLN) or a highly nonlinear fiber (HNLF) with a high nonlinear coefficient and a low dispersion slope to effect four-wave mixing (FWM). The dispersive element can have a low dispersion slope, and the delays effected by the optical TDL can be tunable.

Abstract: The invention relates to a method of generating a feedback signal for adjusting a polarization mode dispersion compensator (PMDC, 21) in a transmission system with alternate-polarization. A first signal (37) is determined by measuring a spectral component of the radio frequency modulation of an optical signal (33) at a particular radio frequency. Preferably, the radio frequency essentially corresponds to half the symbol rate of the optical signal (33). Also a second signal (35) is determined by coupling the optical signal (33) into a delay line interferometer (DLI, 50) having a delay essentially corresponding to the symbol period or an odd multiple of the symbol period between its arms (51, 54). Downstream of the DLI (50), the signal is optical-to-electrically converted. Downstream of the optical-to-electrical conversion, an intensity measurement is performed. The first (37) and second (35) signals are then combined to generate the feedback signal (28).

Abstract: A photon detection system including a photon detector configured to detect single photons, a signal divider to divide the output signal of the photon detector into a first part and a second part, wherein the first part is substantially identical to the second part, a delay mechanism to delay the second part with respect to the first part, and a combiner to combine the first and delayed second parts of the signal such that the delayed second part is used to cancel periodic variations in the first part of the output signal.

Abstract: Exemplary embodiments include a method and systems for impairment compensation in a communication system. The systems can include an electronic phase conjugation system that receives an incoming optical signal from a first section of a fiber optic link, converts the incoming optical signal to an in-phase electric signal and a quadrature electrical signal, and generates a phase conjugated outgoing optical signal from the in-phase and quadrature electrical signals. The phase conjugated outgoing optical signal compensates for impairment of the fiber in the communication system.

Abstract: A receiver or spectrum determiner includes stages, Fourier transforms, phase delays and a summer. The stages are coupled are in pipelined fashion along a signal path. Each of the stages has a respective output for providing at least one respective demodulated signal for the stage. The Fourier transforms are for receiving the respective demodulated signal and providing a respective Fourier transform. The phase delays each have a delay associated with the respective stage. Each phase delay is for receiving the respective Fourier transform and providing a respective phase delayed transform in accordance with the respective stage. The summer is for summing the respective phase delayed Fourier transform from each phase delay. The receiver can be an electronic intelligence (ELINT) receiver.

Abstract: This concerns a protected long-reach PON having a plurality of terminals connected to a distribution network that is fed by both a main and back up feed, each feed including a head end and a repeater. The back up head end had access to a ranging table with data previously obtained by the main head end, thereby speeding up the switch over in the event of a fault with the main feed. In one embodiment, the repeater has a virtual ONU therein, allowing the back up repeater to be ranged by the back up head end, thereby yet further speeding up the ranging procedure. The main and back up repeaters are sufficiently equidistant from the distribution network to allow the back up head to perform normal scheduling without performing a ranging operation on each of the terminals, even if the different terminals transmit at slightly different wavelengths. This is achieved using the ranging information obtained with regard to the back up repeater.

Abstract: An optical transmission system includes a polarization multiplexing optical transmitter for transmitting an optical signal, where an X-polarized signal and a Y-polarized signal each having a having predetermined frame structure are polarization-multiplexed, to an optical fiber transmission path, and a polarization multiplexing receiver for receiving the optical signal that has propagated through the optical transmission path. The polarization multiplexing optical transmitter delays a frame assignment signal (FAS) in the Y-polarized signal, by a predetermined delay time ?, relative to FAS in the X-polarized signal.

Abstract: The present invention relates to chromatic dispersion monitor and method, chromatic dispersion compensator. The chromatic dispersion monitor is used for estimating a chromatic dispersion in accordance with a chromatic dispersion correlation amount sequence, comprising: a phase differential unit, for obtaining a phase difference sequence by performing a phase differential calculation in accordance with the chromatic dispersion correlation amount sequence; a phase difference differential unit, for obtaining a phase difference differential sequence by performing a phase difference differential operation; and a chromatic dispersion estimating unit, for estimating the chromatic dispersion in accordance with the phase difference differential sequence obtained by the phase difference differential unit.

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: Methods, apparatuses, and systems are presented for performing adaptive equalization involving receiving a signal originating from a channel associated with inter-symbol interference, filtering the signal using a filter having a plurality of adjustable tap weights to produce a filtered signal, and adaptively updating each of the plurality of adjustable tap weights to a new value to reduce effects of inter-symbol interference, wherein each of the plurality of adjustable tap weights is adaptively updated to take into account a constraint relating to a measure of error in the filtered signal and a constraint relating to group delay associated with the filter. Each of the plurality of adjustable tap weights may be adaptively updated to drive group delay associated with the filter toward a target group delay.

Abstract: One or more devices of a network having asymmetric delay are configured to participate in time synchronization protocol sessions in which a client device synchronizes its local clock to a master device. In one example, a system includes an optical line terminal configured to receive a time synchronization protocol packet from a grandmaster clock and an optical network unit (ONU) configured to calculate a residence time of the time synchronization protocol packet, encode the residence time into the packet, and to forward the packet to a client device. Moreover, the system may participate in a plurality of time synchronization protocol sessions with a plurality of client devices, such that the client devices become synchronized in frequency and phase.

Abstract: Methods and devices for compensating for chromatic dispersion are shown that include receiving an input data signal, applying a filter to the data signal, and outputting a CD compensated signal. Applying the filter includes convolving known filter coefficients with a plurality of delayed versions of the data signal using addition and at least one inverse sign operation or using lookup tables and combining outputs to produce a CD compensated signal.

Abstract: To efficiently apply jitter to an optical signal using a simple configuration, provided is an optical signal output apparatus that outputs an optical pulse pattern signal including jitter, the optical signal generating apparatus comprising a light source section that outputs an optical signal having an optical frequency corresponding to a frequency control signal; an optical modulation section that modulates the optical signal output by the light source section, according to a designated pulse pattern; and an optical jitter generating section that delays an optical signal passed by the optical modulation section according to the optical frequency, to apply jitter to the optical signal.

Abstract: An apparatus for simulating radio frequency (RF) signal propagation characteristics in a wireless communication network is disclosed. The apparatus includes a first RF terminal and a second RF terminal. A first optical modulator is in electrical communication with the first RF terminal. An optical delay line is in optical communication with the first optical modulator. A first optical demodulator is in optical communication with the optical delay line and in electrical communication with the first RF terminal. A second optical demodulator is in optical communication with the optical delay line and in electrical communication with the second RF terminal. A second optical modulator is in electrical communication with the second RF terminal and in optical communication with the optical delay line.

Abstract: A distortion compensation circuit including a configurable delay may be used with one or more non-linear elements, such as a laser, to compensate for distortion generated by the non-linear element(s), for example, in broadband RF applications. Embodiments of the distortion compensation circuit may include a primary signal path with a configurable delay segment and a secondary signal path including at least one distortion generator. The configurable delay segment may be selectively configured to provide different delay settings to accommodate different RF loading conditions such that the delayed RF signal on the primary signal path is aligned with the distortion products generated on the secondary signal path when combined to form an RF signal with distortion compensation.

Abstract: The present invention relates to a higher-order dispersion compensation device (210), the device being adapted to cooperate with a pair of optical components (P1, P2), e.g. a pair of prisms, being arranged to compensate first-order dispersion by separating different wavelengths spatially. The compensation device (210) has the form of a phase plate, wherein the phase change for each wavelength is adjusted by designing the height (h) at the corresponding position (x) of the plate so as to substantially compensate for higher-order dispersion. The invention is advantageous for obtaining a higher-order dispersion compensation device which is relatively simple to construct and use making it a quite cost-effective device. The invention also relates to a corresponding optical system and method for compensating dispersion where this is important, e.g. in a multiple-photon imaging system.

Abstract: An optical transmitter is provided for transmitting a wavelength multiplexed signal comprising an intensity modulation optical signal and a phase modulation optical signal through a transmission line. The optical transmitter includes a bit time difference given signal generator for generating at least two optical signals having a bit time difference therebetween, from the wavelength multiplexed signal. The optical transmitter further includes a wavelength multiplexed signal output unit to which at least two optical signals are input from the bit time difference given signal generator, and which generates and outputs a wavelength multiplexed signal in which the bit time difference was given between the phase modulation optical signal and the phase modulation optical signal.

Abstract: One embodiment of the present invention provides a system that accommodates different clock frequencies in an Ethernet passive optical network (EPON). The system receives a signal from an optical line terminal (OLT) at an optical network unit (ONU) and derives an OLT clock. The system also maintains a local clock. The system further receives from the OLT an assignment for an upstream transmission window, during which the ONU can transmit an upstream data burst to the OLT based on the local clock. The system adjusts the number of bits of the data burst without affecting the payload data carried in the data burst, thereby allowing the data burst to fit properly within the upstream transmission window and compensating for frequency differences between the local clock and the OLT clock. The system transmits the data burst based on the local clock in the upstream transmission window.

Abstract: A method and system for generating multi-subcarriers is disclosed. Re-circulating frequency shifters—based on the frequency shifting in two cascading phase modulators—are used to generate 112 subcarriers with stable architecture since there is no direct current bias in phase modulators.

Abstract: An apparatus for simulating radio frequency (RF) signal propagation characteristics in a wireless communication network is disclosed. The apparatus includes a first RF terminal and a second RF terminal. A first optical modulator is in electrical communication with the first RF terminal. An optical delay line is in optical communication with the first optical modulator. A first optical demodulator is in optical communication with the optical delay line and in electrical communication with the first RF terminal. A second optical demodulator is in optical communication with the optical delay line and in electrical communication with the second RF terminal. A second optical modulator is in electrical communication with the second RF terminal and in optical communication with the optical delay line.

Abstract: The present application describes methods and systems for use in a communications network. More specifically, a method of deploying an optical demodulator arrangement having at least one interferometer in a network that transmits an optical signal is provided. The optical signal may include one or more on-off-keyed signals and one or more DMPSK signals. In some embodiments, the DMPSK signal is a DQPSK signal. The network may include one or more of fiber spans carrying the signals. The interferometer may have a first optical path and a second optical path and a time delay is formed between the first and second optical paths. The method may involve determining a cross-talk penalty that results from cross-phase modulation between the channels, and determining a time delay value for the interferometer. The time delay value may be determined based at least in part on determined the cross-talk penalty.

Abstract: A PPM transmitter includes an optical clock generator for generating equally-spaced optical pulses with a sampling period T; an encoder for transforming an incoming waveform U(t) into a linear combination V(t) of U(t) and a delayed output V(t?kT) according to a rule V(t)=U(t)+aV(t?kT), where k is a positive integer, V(t) is voltage generated by the encoder and a is a coefficient; and an optical delay generator for delaying optical pulses generated by the optical clock generator in proportion to the voltage V(t), such that ?tn=bV(t), where b is another coefficient and where ?tn is the amount of delay imposed by the optical delay generator. The PPM transmitter functions with a PPM receiver for communicating data without the need to transmit or otherwise provide a clock signal. The PPM receiver decodes an original series of the delayed optical pulses Q(t) and a second series Q(t?ckT) delayed by ckT where c is a coefficient.

Abstract: A robustly stabilized communication laser can output a multimode optical signal remaining aligned to a coordinate of a dense wavelength division multiplexing (“DWDM”) grid while responding to a fluctuating condition or random event, such as, without limitation, exposure to a temperature fluctuation, stray light, or contamination. Responsive to the fluctuating condition, energy can transfer among individual modes in a plurality of aligned longitudinal modes. Modes shifting towards a state of misalignment with the DWDM coordinate can attenuate, while modes shifting towards a state of alignment can gain energy. Fabrication processes and systems and light management, such as beam steering, epoxy scaffolds, spectral adjustments, mode matching, thermal expansion control, alignment technology, etc. can facilitate nano-scale control of device parameters and can support low-cost fabrication.

Abstract: The optical transmission equipment includes: a demultiplexer for demultiplexing a transmitted wavelength-multiplexed optical signal to first and second optical signals; a first variable dispersion compensation unit; a second variable dispersion compensation unit; a first error detector; a second error detector; and a dispersion compensation control unit for controlling dispersion compensation amounts of the first and second variable dispersion compensation units based on the detection result of the first or second error detector. Upon detection of a signal error in the first optical signal, the first variable dispersion compensation unit is controlled to change from a first compensation amount to a third compensation amount, and the second variable dispersion compensation unit is controlled to change from a second compensation amount to a fourth compensation amount.

Abstract: An optical signal transmission control apparatus that controls transmission of optical signals transmitted via a plurality of redundant routes. The optical signal transmission control apparatus includes a delay difference adjusting unit that adjusts a transmission delay difference between the optical signals of each route by converting a wavelength of the optical signal and making the optical signal with a converted wavelength pass through a waveguide in which a transmission delay of the optical signal changes continuously depending on the wavelength, and a waveform degradation compensating unit that compensates degradation of a waveform of the optical signal, while maintaining the transmission delay difference adjusted by the delay difference adjusting unit.