Abstract: The invention relates to a method of operating a passive optical network. The passive optical network comprises an optical line termination being connected via optical fibers to a number of network terminations. The method comprises the step of generating an optical signal to be transmitted on one of the optical fibers comprising a number of signal states. The method is characterized in that the number of signal states is changed.

Abstract: A number of optical calibration systems and methods are disclosed. One optical communication system embodiment includes a number of light sources for providing a number of light beams, a number of optical paths, where each of the optical paths is positioned to receive one of the light beams, a number of optical modulators, where each modulator receives a radio frequency signal and receives one of the light beams from one of the optical paths, where each modulator modulates the light beam it receives based upon the radio frequency signal it receives to form an optical signal, and a number of optical biasing components, where each optical signal can be adjusted by at least one of the optical biasing components to calibrate the optical signals.

Abstract: In a CWDM optical transmission system of the present invention, in place of an optical signal of at least one wave among a plurality of optical signals corresponding to a CWDM system, a DWDM light output from an additional light transmission unit of a DWDM system is given to a multiplexer via a variable optical attenuator, and multiplexed with the optical signals corresponding to CWDM, to be sent out to a transmission path. At this time, the total power of the DWDM light sent out to the transmission path, is attenuated by the variable optical attenuator, so as to be approximately equal to the power per one wavelength of the CWDM light. On an optical reception terminal, the light propagated through the transmission path is demultiplexed by a demultiplexer, and the DWDM light corresponding to the additional wavelengths is amplified by an optical amplifier and thereafter, received by an additional light reception unit.

Abstract: An output stage for WDM information transmission transmits a plurality of carrier waves modulated by an information signal and a filling lightwave. A first control circuit controls a desired power signal which determines the power of the filling light source so that the total power of carrier and filling lightwaves detected by a photodetector is held constant at a predetermined reference level. The filling light source is part of an assembly which is replaceably mounted at a first mounting location of the output stage. At a second mounting location of the output stage a second assembly comprising a second filling light source is mounted or adapted to be mounted. An auxiliary circuit is adapted to provide one of the two filling light sources with a continuously decreasing second desired power signal.

Abstract: Method and apparatus for operating for operating an optical network including a shared laser array are disclosed. An example apparatus includes include a first plurality of N lasers. Each laser of the first plurality of N lasers is configured to output a respective optical seed signal having a respective wavelength. The example apparatus further includes a first optical coupler coupled with the first plurality of N lasers. In the example embodiment, the first optical coupler is configured to multiplex the respective optical seed signals of the first plurality of N lasers onto a plurality of N optical fibers. In this example, each optical fiber of first plurality of N optical fibers transmits each of the respective optical seed signals produced by the plurality of N lasers to a respective distribution node for distribution to N respective optical network units, where the optical network units use the optical seed signals to seed respective optical transmitters located at the N optical network units.

Abstract: A WDM optical transmission system of the invention: detects an optical waveform of an intensity-modulated optical signal adjacent to a phase-modulated optical signal in a wavelength range; calculates a phase modulation drive waveform for canceling XPM of the phase-modulated optical signal affected by the adjacent intensity-modulated optical signal in the optical transmission path, based on the detected result; and additionally phase-modulates the phase-modulated optical signal synchronously with the adjacent intensity-modulated optical signal, according to the drive waveform, to thereby compensate the XPM. As a result, excellent transmission characteristics can be realized.

Abstract: For transmitting information on an optical fiber, a plurality of information carrier channels at different carrier frequencies and a plurality of filling channels are used. The filling channels are transmitted together with the information carrier channels along the fiber. The total optical power of the information carrier channels and the filling channels transmitted on the fiber is maintained constant by compensating every change of the optical power of the information carrier channels by an inverse change of the optical power of the filling channels. The change of the optical power of the filling channels is distributed to the individual filling channels such that a minimum displacement of the center of gravity of the common spectrum of information carrier channels and filling channels results.

Abstract: A multiwavelength transmitter comprises several laser sources (1) each configured to generate light of a different wavelength and a first array waveguide grating (2) arranged to direct light from each of the laser sources (1) into a first waveguide. The transmitter further comprises several electroabsorption modulators (7) each arranged to modulate light at one of the wavelengths with a respective data signal and a second array waveguide grating (6) arranged to direct each of said different wavelengths of light from the first waveguide to a respective one of the modulators (7). The optical modulators (7) are reflective optical modulators and the second array waveguide grating (6) is arranged to direct the modulated light reflected from each of the optical modulators (7) back into the first waveguide. An optical circulator (5) is provided in the first waveguide to couple modulated light from the second array waveguide grating (6) into an output waveguide.

Abstract: A communication system between head-ends and end-users is provided which expands bandwidth and reliability. A concentrator receives communication signals from a head-end and forwards the received communication signals to one or more fiber nodes and/or one or more mini-fiber nodes. The concentrator demultiplexes/splits received signals for the mini-fiber nodes and the fiber nodes and forwards demultiplexed/split signals respectively. The mini-fiber nodes may combine signals received from the head-end with loop-back signals used for local medium access control prior to forwarding the signals to the end-users. Upstream data are received by the mini-fiber nodes and/or fiber node and transmitted to the concentrator. The concentrator multiplexes/couples the mini-fiber node and the fiber node upstream signals and forwards multiplexed/coupled signals to the head-end.

Abstract: A light source apparatus with modulation function has a wavelength conversion module (75) composed of a nonlinear optical material with a structure having a nonlinear constant modulated periodically. It outputs a difference frequency or sum frequency produced by multiplexing pumping light from semiconductor laser light sources (71) and (72) with different wavelengths through a WDM coupler (74) and by launching the multiplexed light into the optical waveguide. The semiconductor laser light source (72) includes a diffraction grating. The semiconductor laser light source (71) includes a section for modulating output light emitted from its semiconductor laser, and is connected to an external FBG (73) which has a reflection band narrower than a resonance wavelength spacing determined by the device length of the semiconductor laser. The FBG (73) is supplied with the modulated output.

Abstract: An optical device is provided with first and second inputs. A first coupler coupled is coupled to the first input and produces at least a first and second output. A second coupler is coupled to the second input and produces at least a first and second output. A third coupler is coupled to the first output of the first coupler and to the first output of the second coupler. A fourth coupler is coupled to the second output of the first coupler and to the second output of the second coupler. First and second crossing waveguides are provided with an angle selected to minimize crosstalk and losses between the first and second cross waveguides. The first crossing waveguide connects one of the first or second outputs from the first coupler with an input of the fourth coupler. The second crossing waveguide connects one of the first or second outputs from the second coupler with an input of the third coupler. A first phase shifter is coupled to the first and second waveguides.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: A transmissive active channel element is provided in each signal channel of a monolithic multi-channel TxPIC where each channel also includes a modulated source. The active channel element functions both as a power control element for both monitoring and regulating the output channel signal level of each signal channel and as a modulator for channel wavelength tagging or labeling to provide for wavelength locking the modulated sources. The power regulating function is also employed to control the channel signal power outputs of each channel to be uniform across the channel signal array. All of these functions are carried out by a feedback loop utilizing digital signal processing.

Abstract: A device for digitising an electrical signal comprising (A) at least two continuous wave lasers each being adapted to produce light at a different wavelength; (B) a dispersive optical chopper adapted to chop the output of each of the lasers into optical pulse trains, introduce a predetermined delay between each of the optical pulse trains and to combine the optical pulse trains into a single optical path; (C) a modulator having an input port adapted to receive the output of the dispersive optical chopper, an output port and at least one optical path extending therebetween, the modulator being adapted to receive a microwave signal and to modulate the amplitude of the optical signal in the optical path in response to the microwave signal; (D) an optical splitter for splitting the signal received from the output port of the modulator into a plurality of wavelength dependent signal paths; and (E) a plurality of analogue to digital converters each connected at least one wavelength dependent signal path for convert

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: An optical transmitter system supplies a plurality of different wavelength optical radiation components to a transmission element which, in operation, is connected to the transmitter system for conveying the different wavelength radiation components to a respective receiver. The supply of the wavelength components is interrupted, preferably in response to a loss of the wavelength components at the respective receiver. A timer provides respective restart times which differ one to another for the wavelength radiation components. The supply of the wavelength components is restarted, following an interruption, at the respective restart times provided by the timer.

Abstract: Various methods and apparatuses are described in which an array of optical gain mediums capable of lasing are contained in a single integral unit. The array may contain four or more optical gain mediums capable of lasing. Each optical gain medium capable of lasing supplies a separate optical signal containing a band of wavelengths different than the other optical gain mediums capable of lasing in the array to a first multiplexer/demultiplexer. A connection for an output fiber exists to route an optical signal to and from a passive optical network.

Abstract: This invention provides a system that combines a wavelength multiplexer with an FM discriminator for chirp reduction and wavelength locker in a filter to produce a wavelength division multiplexed signal with reduced chirp. A partially frequency modulation laser signal is converted into a substantially amplitude modulation laser signal. This conversion increases the extinction ratio of the input signal and further reduces the chirp. A wavelength division multiplexing (WDM) method is used for transmitting high capacity information through fiber optics systems where digital information is carried on separate wavelengths through the same fiber. Separate transmitters normally generate their respective signals that are transmitted at different wavelengths. These signals are then combined using a wavelength multiplexer to transmit the high capacity information through the fiber optic system.

Abstract: An ultra-long fiber-optic transmission system is configured in accordance with the current telecom standards and particularly advantageous for transmission data at a long distance which may exceed 400 km between adjacent nodes. The disclosed system has at least one intermediary amplifying node provided with a supervisory optical channel (SOC) which comprises a transponder operative to select the direction in which a supervisory channel signal (SCS), carrying information about the fiber break and malfunction of WDM channels, is transmitted along the SOC. The transponder further includes a receiver operative to measure the power of incoming and a Raman controller coupled to the receiver and to either turn or turn off a pump of Raman amplifier based on determination of whether the measured power of the SCS is lower than or at least equal to a reference value. The transponder is further configured with a transmitter configured as a fiber laser which operates in at least two modes.

Abstract: Provided is a multimode optical transmission system capable of reducing an influence of multimode dispersion occurring when an optical signal is transmitted in multimode. Light sources (101 to 10m) respectively convert inputted electrical signals into a plurality of optical signals respectively having different wavelengths, and respectively output the plurality of optical signals. A wavelength multiplexing section (200) performs wavelength multiplexing of the plurality of optical signals outputted from the light sources (101 to 10m), and outputs a resultant signal as a wavelength multiplexed signal. A multimode optical transmission path (300) optically transmits the wavelength multiplexed signal in multimode. A mode processing section (400) extracts, from the wavelength multiplexed signal transmitted through the multimode optical transmission path (300), a plurality of optical signals each being in a mode having a particular wavelength and a particular propagation constant.

Abstract: The present invention provides an optical add/drop multiplexer including an optical power control unit for performing a control of an optical power by the unit of each signal light included in the wavelength multiplexed light, wherein the optical power control unit includes control logic for implementing a first control mode in which a transition to an automatic control of the optical power and release from the aforementioned control are carried out by comparing the optical power with a threshold value, and a second control mode in which a transition to an automatic control of the optical power is carried out based on control information of a notification by another of the optical add/drop multiplexers and release from the automatic control is carried out based on the comparison between the optical power and the threshold value.

Abstract: A method for pre-emphasising transmitted signals in channels for multiplex signals along a transmission path comprising supply and/or branch points is provided. According to the method, relative degradations of the signal-to-noise intervals between transmitted signals via any category or group of channels—i.e. express and add or drop channels or add-drop channels are taken into account. A point-to-point link and for transparent optical networks may be used. To this end, the average signal powers of different channel groups are set relative to one another in order to obtain predetermined signal-to-noise intervals for each group. In addition, the signal-to-noise intervals within a channel group are equalized at their termination points. Regulation protocols for controlling the pre-emphasising steps are provided.

Abstract: The present invention relates to a wavelength-tunable light source whose output wavelength can be externally controlled and a wavelength-division multiplexed transmission system using the source. A wavelength-tunable light source in accordance with the present invention is constituted to be able to vary the output wavelength of a Fabry-Perot laser diode, that is wavelength-locked to an injected light, by controlling the wavelength of the injected light. A wavelength-tunable light source in accordance with the present invention provides comparatively large output power and excellent economic features. The present invention also presents a wavelength-division multiplexed transmission system using, the wavelength-tunable light source.

Abstract: Disclosed is a method and apparatus for optically modulating and transmitting source data. An optical comb comprising optical tones having a frequency spacing equal to ?f is generated by an optical comb generator. Selected ones of the optical tones in the optical comb are modulated according to the source data to produce a comb of modulated optical tones. At least one optical tone in the optical comb is frequency shifted by a frequency less than ?f to produce a frequency shifted unmodulated optical reference tone. The optical comb, the frequency shifted unmodulated optical reference tone and the comb of modulated tones are multiplexed onto at least one optical path.

Abstract: An optical transmitter has a resonance wavelength characteristic that varies with the refractive index of the optical transmitter. The optical transmitter receives a narrow band injected wavelength signal from an incoherent light source. The controller substantially matches a resonant wavelength of the optical transmitter to the wavelength of the injected wavelength signal by changing the refractive index of the optical transmitter to substantially match the resonant wavelength of the optical transmitter and the wavelength of the injected wavelength signal. A detector measures a parameter of the optical transmitter to provide a feedback signal to a controller to determine when the resonant wavelength of the optical transmitter and the wavelength of the injected wavelength signal are substantially matched.

Abstract: An optical communications transmitter includes a oscillator source, producing a clock signal, a data source, producing a data signal, a modulating circuit for modulating the clock signal using the data signal to produce modulating signals, optical drivers, receiving the modulating signals and producing optical driving signals based on the modulating signals and optical emitters, producing small numbers of photons based on the optical driving signals. The small numbers of photons are time-correlated between at least two separate optical transmission wavelengths and quantum states and the small number of photons can be detected by a receiver to reform the data signal.

Abstract: A method of optical communication includes generating an amplified optical signal from at least a portion of a first optical signal having a first carrier wavelength, ?1. The amplified optical signal is applied to Brillouin media to stimulate generation of a Brillouin effect signal at a wavelength ?2. The Brillouin effect signal is modulated to produce a second optical signal having a second carrier wavelength, ?2. In one embodiment, the first optical signal is a downstream optical signal and the second optical signal is an upstream optical signal of a passive optical network.

Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.

Abstract: Methods and apparatus for supporting a plurality of modulation formats using a single transmitter are disclosed. According to one aspect of the present invention, a transmitter arrangement that provides a signal to a modulator that creates an optical data stream from the signal includes an encoder and a switching/filtering arrangement. The encoder has a state that is varied between first and second encoder states. If the state is the first encoder state, the encoder encodes the signal in a format associated with an optical duobinary (ODB) modulation format. Otherwise, the encoder does not encode the signal in the format associated with the ODB modulation format. The switching/filtering arrangement receives the signal from the encoder, and provides the signal to the modulator. If the variable state of the encoder is the first encoder state, the switching/filtering arrangement has a low bandpass configuration. Otherwise, the switching/filtering arrangement has a high bandpass configuration.

Abstract: A WDM network (R) comprises an optical fiber (F) connected to a hub (H) via an input of a demultiplexer (DX) having N outputs to communications stations (Si-Sn) able to deliver and/or receive spectral multiplexes of modulated optical signals with different wavelengths, via coupling means (CP, CP?, MXB). The communications stations (Sn?1) are adapted to deliver spectral multiplexes of modulated optical signals from a given one of P disjoint bands of wavelengths. At least one of the coupling means (MXB) is a 2×1 band multiplexer comprising i) an output connected to a downstream portion of the optical fiber (F), ii) a first input connected to one of the stations (then referred to as the “primary” station) and adapted to its band of wavelengths, and iii) a second input connected to an upstream portion of the optical fiber (F) and adapted to channels having wavelengths different from those of the channels passing through the first input.

Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.

Abstract: Electro-optic amplitude varying elements (AVEs) or electro-optic multi-function elements (MFEs) are integrated into signal channels of photonic integrated circuits (PICs) or at the output of such PICs to provide for various optical controlling and monitoring functions. In one case, such PIC signal channels may minimally include a laser source and a modulator (TxPIC) and in another case, may minimally include a photodetector to which channels, in either case, an AVE or an MFE may be added.

Abstract: A wavelength division multiplexing transmission system, the system comprising: a plurality of channels at different wavelengths, each channel comprising a transmitter, a receiver, and one or more amplifiers, the system further comprising an encoder for encoding data with a coding, and; a decoder for decoding transmitted data; prioritizing means for prioritizing the data on each channel; monitoring means for monitoring directly or indirectly, raw (uncorrected) bit errors on each channel; power adjusting means for, varying the power on a channel in response to the bit error rate.

Abstract: An optical element mounting substrate where a plurality of light emitting elements have been mounted on the same plane, a lens array for collimating a plurality of light emitted from the plurality of light emitting elements, and a wavelength multiplexing/demultiplexing device are prepared. The wavelength multiplexing/demultiplexing device has typically mounted both a wavelength selecting filter and a mirror on front and rear planes of a transparent substrate. These three components are mounted within a package at a desirable angle position. Optical axes of respective wavelengths of the wavelength multiplexing/demultiplexing device are determined based upon a thickness and an angle of the light emitting element mounting substrate, and are arrayed on a straight line of a horizontal plane. As a consequence, if the respective light emitting elements are arranged on the optical axes which are exclusively determined by a design work, then optical multiplexing/demultiplexing operations can be carried out.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: An all optical network for optical signal traffic has at least a first ring with at least one transmitter and one receiver. The first ring includes a plurality of network nodes. At least a first add/drop broadband coupler is coupled to the first ring. The broadband coupler includes an add port and a drop port to add and drop wavelengths to and or from the first ring, a pass-through direction and an add/drop direction. The first add/drop broadband coupler is configured to minimize a pass-through loss in the first ring and is positioned on the first ring.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: Techniques and system implementations for fiber optic transmission systems for suppressing fiber induced distortions and modulation-induced distortions as well as increasing the link power and RF gain.

Abstract: An optical transmitter comprises an array of modulated sources having different operating wavelengths approximating a standardized wavelength grid and providing signal outputs of different wavelengths. Signal outputs of the modulated sources are optically coupled to inputs of the wavelength selective combiner to produce a combined signal output from the combiner. The wavelength selective combiner has a wavelength grid passband response approximating the wavelength grid of the standardized wavelength grid. A first wavelength tuning element is coupled to each of the modulated sources and a second wavelength tuning element is coupled to the wavelength selective combiner. A wavelength monitoring unit is coupled to receive a sampled portion the combined signal output from the wavelength selective combiner. A wavelength control system is coupled to the first and second wavelength tuning elements and to the wavelength monitoring unit to receive the sampled portion of the combined signal output.

Abstract: A method and apparatus for generating a multi-wavelength pulse train use a technique referred to as time-lens compression. The time-lens is formed of a phase modulator in series with a dispersion element. In addition to pulse compression, this time-lens simultaneously displaces the pulses according to their center wavelengths, resulting in a temporally evenly spaced multi-wavelength pulse train. An aberration correction technique, based on the temporal analog of a spatial correction lens, can also be employed improve the quality of the compressed pulses. Through use of CW DFB lasers and electrooptic phase modulators, the all-fiber system allows complete tunability of temporal spacing, spectral profile and repetition rate.

Abstract: An optical transmitter comprising: (i) an electrical switch; (ii) a laser array comprising a plurality of tunable laser elements; and (iii) an Optical Spectrum Reshaper (OSR) used to reshape the output pulses from the laser elements in the laser array; wherein the electrical switch takes an input electrical digital signal and selectively directs it to a specific laser element in the DFB laser array.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: An optical transmitter comprises a monolithic transmitter photonic integrated circuit (TxPIC) chip that includes an array of modulated sources formed on the PIC chip and having different operating wavelengths approximating a standardized wavelength grid and providing signal outputs of different wavelengths. A wavelength selective combiner is formed on the PIC chip having a wavelength grid passband response approximating the wavelength grid of the standardized wavelength grid. The signal outputs of the modulated sources optically coupled to inputs of the wavelength selective combiner to produce a combined signal output from the combiner. A first wavelength tuning element coupled to each of the modulated sources and a second wavelength tuning element coupled to the wavelength selective combiner. A wavelength monitoring unit is coupled to the wavelength selective combiner to sample the combined signal output.

Abstract: Various methods, systems, and apparatuses is described in which a passive-opticalnetwork includes a first multiplexer/demultiplexer, a second multiplexer/demultiplexer, a wavelength tracking component, and a transmission wavelength controller. The first multiplexer/demultiplexer is located in a first location. The second multiplexer/demultiplexer is located in a second location remote from the first location. The wavelength tracking component determines the difference between the transmission band of wavelengths of the first multiplexer/demultiplexer and the second multiplexer/demultiplexer to provide a control signal to match the transmission band of wavelengths of the first multiplexer/demultiplexer and the second multiplexer/demultiplexer. The transmission wavelength controller alters an operating parameter of the first multiplexer/demultiplexer based on the control signal to control the transmission band of wavelengths of the first multiplexer/demultiplexer.

Abstract: The communication state information providing system comprises a cellular phone of an information provider, and an information providing device having an information receiving unit for receiving, via a wireless LAN, the communication state information transmitted from the cellular phone, a communication state information storage unit for storing the communication state information received by the information receiving unit associated with the phone number specifying the cellular phone, and an information transmitting unit for transmitting the communication state information stored in the communication state information storage unit to a destination associated with the phone number of the cellular phone.

Abstract: WDM optical tranmsmission equipment with redundant configuration includes a plurality of tranmitters. Each tranmitter includes active and standby panels including active and standby optical transmission circuits respectively having active and standby attenuators for controlling an attenuation amount of each output of the active and standby optical transmission circuits; and a coupler combining the outputs of the active and standby attenuators.

Abstract: A transmitter subsystem generates an optical signal which contains multiple subbands of information. The subbands have different polarizations. For example, in one approach, two or more optical transmitters generate optical signals which have different polarizations. An optical combiner optically combines the optical signals into a composite optical signal for transmission across an optical fiber. In another aspect, each optical transmitter generates an optical signal containing both a lower optical sideband and an upper optical sideband (i.e., a double sideband optical signal). An optical filter selects the upper optical sideband of one optical signal and the lower optical sideband of another optical signal to produce a composite optical signal.

Abstract: The present invention relates to a light source apparatus. The light source apparatus includes a plurality of optical pulse train generation sections; an optical switch section capable of selectively outputting an optical pulse train to be taken as an optical pulse train for current use; an output light generation section capable of generating continuous light of multiple wavelengths from said optical pulse train output from said optical switch section; and an optical switch control section for controlling said optical switch section to switch an output of said optical pulse train for current use from said optical switch section, in accordance with the states of respective optical pulse trains generated by said plurality of optical pulse train generation sections and without involvement of instantaneous power interruption.

Abstract: A photonic link system for transmitting and receiving an optical signal in accordance with an input signal is disclosed. The system includes a photonic transmitter and a photonic receiver. The photonic transmitter includes a first signal path including a first photonic modulator for producing a first output optical signal modulated by the input signal and a second signal path in parallel with the first path photonic path where the second signal path also includes a second modulator for producing a second output optical signal modulated by the input signal. The relative gain of the first and second signal paths is different to provide first and second output optical signals of different relative gain. The photonic receiver includes a first input to receive the first output optical signal from the photonic transmitter and a second input to receive the second output optical signal from the photonic transmitter.

Abstract: An optical wavelength multiplexing frequency shift keying modulation system. The system includes an optical wavelength multiplexing signal acquisition unit for outputting an optical wavelength multiplexing signal. A n optical frequency shift keying modulation unit acquires an optical frequency shift keying signal, including an upper side band signal and a lower side band signal, by performing frequency modulation to the optical wavelength multiplexing signal output from the optical wavelength multiplexing signal acquisition unit. An optical frequency shift keying signal separation unit separates the optical frequency shift keying signal output from the optical frequency shift keying modulation unit into an upper side band signal and a lower side band signal.