Abstract: A pump probe measuring device (1) comprises: an ultrashort optical pulse laser generator (2) for generating a first ultrashort optical pulse train which is a pump light (3a), second and third ultrashort optical pulse trains (3b), (3c) which are probe lights; an optical shutter unit (6) to which the second and the third ultrashort pulse trains (3b), (3c) are introduced; and a detecting unit (20) including an irradiation optical system (8) for directing the pump light (3a), the first probe light (3b) and the second probe light (3c) to a sample (7), a sensor (11) for detecting a probe signal from the sample (7), and a phase-sensitive detecting means (12) connected to the sensor (11).

Abstract: An Integrated Laser Field Conjugation System (ILFCS) for end-to-end compensation of high-energy laser for propagation through turbulence with non-cooperative target. ILFCS using interferometric slaving technique and stand-alone adaptive optical systems to effect pre-compensation of amplitude and phase aberrations in turbulent medium, providing pre-compensation for aberrations in a laser amplifier. Performing compensation functions in low-power beam paths, increasing capability, reducing cost, reducing size compensation components for phase correction devices. Pre-compensating low-power master oscillator beam for aberrations in both high-power amplifier and turbulent propagation path-to-target with configuration enabling wavefront sensing of aberrations. Can be configured to perform phase compensation, or compensation of phase/amplitude aberrations. Capability to compensate aberrations in master oscillator beam.

Abstract: A tunable laser includes a resonator including a highly reflecting mirror and a partially reflecting mirror; a gain medium disposed in the resonator; a birefringence filter disposed in the resonator; and an excitation device that excites the gain medium. In the tunable laser, light that passes through the birefringence filter oscillates between the highly reflecting mirror and the partially reflecting mirror. An oscillation wavelength is switched by rotating the birefringence filter. The birefringence filter includes a first birefringent plate and a second birefringent plate, which have principal dielectric axes parallel to optical surfaces thereof. An absolute value of an angle formed by the principal dielectric axis of the first birefringent plate and the principal dielectric axis of the second birefringent plate is larger than zero.

Abstract: A system for synchronizing a first clock and a second clock includes a receiver associated with the first clock, configured to receive a remote pulse from the second clock. The remote pulse has a pulse repetition frequency and spectral characteristics that are known to the local clock. The system also includes a local pulse emitter configured to create a local pulse at the first clock, and optics configured to align the local pulse and the remote pulse. The system further includes an interferometer configured to create an interference pattern between the local pulse and the remote pulse. A controller is provided that is configured to calculate a time delay between the first clock and the second clock based on the interference pattern between the local pulse and the remote pulse.

Abstract: A laser assembly is configured with a frequency conversion laser head operative to shift a fundamental frequency of input light to the desired frequency of an output light. The frequency conversion laser head includes a dump means operative to guide an unconverted output light at the fundamental frequency outside the case of the frequency conversion laser head. The dump means is configured with a guide optics operative to couple the output light at the fundamental frequency to a fiber terminating outside the case of the frequency conversion laser head.

Abstract: The present invention relates to a frequency shifter in an optical path containing a pulsed laser source, and it is characterized in that it comprises at least one frequency shifter (12, 13) containing an optical propagation medium, the optical path length of which is modified according to the desired frequency shift during at least one pulse among n consecutive pulses from the laser, where n?1.

Abstract: A pump probe measuring device (1) includes an ultrashort optical pulse laser generator (11) for generating a first ultrashort optical pulse train, which becomes a pump light, and a second ultrashort optical pulse train, which becomes a probe light, a delay time adjusting unit (15) for adjusting a delay time between ultrashort optical pulse trains, a first pulse picker and a second pulse picker (13, 14) for accepting each of the first and the second ultrashort optical pulse trains and allowing only one pulse to be transmitted at an arbitrary repetition periodicity, thus reducing the effective repetition frequency of the optical pulses, a delay time modulation unit (10) for periodically changing a position through which pulses are transmitted by the first and the second pulse pickers (13, 14), an irradiation optical system (16) for applying pump light and probe light to a sample (19), a measuring unit (20) for detecting probe signals from a sample (19), and a lock-in amplifier (18).

Abstract: A high frequency electrical signal control device comprises a transmitter for generating a high frequency electrical signal, a receiver, a transmission line for propagating the electrical signal, and a structure for radiating the electrical signal propagated through the transmission line to the space or receiving a signal from the space. The degree of coupling of the electrical signal between the space and the transmission line provided by the structure can be variably controlled.

Abstract: A high frequency electrical signal control device comprises a transmitter for generating a high frequency electrical signal, a receiver, a transmission line for propagating the electrical signal, and a structure for radiating the electrical signal propagated through the transmission line to the space or receiving a signal from the space. The degree of coupling of the electrical signal between the space and the transmission line provided by the structure can be variably controlled.

Abstract: An optical antenna collects, modifies and emits energy at light wavelengths. Linear conductors sized to correspond to the light wavelengths are used. Nonlinear junctions of small dimension are used to rectify an alternating waveform induced upon the conductors by the lightwave electromagnetic energy. The optical antenna and junctions are effective to produce harmonic energy at light wavelengths. The linear conductors may be comprised of carbon nanotubes that are attached to a substrate material, which may then be connected to an electrical port.

Abstract: A method for characterizing one or more properties of a sample using acoustic waveforms is disclosed, and comprises directing a sequence of at least three optical pulses to the sample to generate an acoustic response in the sample at a frequency corresponding to the pulse sequence, varying the timing of one or more of the pulses in the sequence to vary the frequency of the acoustic response in the sample, and measuring the strength of the acoustic response as a function of the varied frequency to determine information about the sample.

Abstract: A communications apparatus and method use tapped delay lines as multiplexers and demultiplexers. In one embodiment, a receiver (100) uses a tapped delay line (110) as a demultiplexer to acquire a burst communication at very high data rates in the range of 2.5 to 80 Gbps with low preamble overhead. A sliding window correlator (114) continually samples the delay line (110) to determine when a PN encoded word is contained therein. The transmission frequency is pre-acquired before any data is present through the use of a ring oscillator frequency calibration loop (130) that is imbedded within the tapped delay line (110).

Abstract: A system for sensing characteristics of the environment is disclosed. Sensors utilize exponential growth of a signal initiated by interaction of a sensor element with characteristics of the environment. Specific substances in the environment can be detected. The sensor element may be intrinsically sensitive to the specific substance or can be coated with a material that is sensitive to the specific substance. The sensor component is designed such that it can be made to cause exponential growth of a system signal. The exponential growth of the sensor signal is produced by parametric amplification.

Abstract: A frequency converter having no solid-state devices having nonlinear characteristics and no complex resonator structure and operable in a wide frequency range from microwave frequencies to terahertz wave frequencies. An input section (1) inputs an input wave into a high-frequency transmission line (2). A waveguide portion of an output section (6) reflects the input wave. A laser light source (4) inputs a laser beam into an optical delay circuit (5). The optical delay circuit (5) delays the laser beam and directs the delayed laser beam into a high-frequency transmission line (2) and a substrate (3). The laser beam transmitted through the optical delay circuit (5) produces an electron-hole plasma over the surface of the substrate (3) such as of a semiconductor thereby to short-circuit the high-frequency transmission line (2) and to reflect the input wave. The reflection point moves at high speed together with the laser beam, thereby converting the frequency on the same principle as the Doppler effect.

Abstract: Fiber Bragg writing devices comprising solid state lasers are provided. The solid state lasers comprise optical parametric oscillators and emit moderate peak-power output beams at wavelengths which are suitable for efficient production of fiber Bragg gratings without causing embrittlement of the optical waveguide. These solid state lasers generate output beams with wavelengths of approximately 240 nm, in order to match the primary absorption peak in the ultraviolet range for a typical optical waveguide. Some of these solid state lasers generate tunable wavelength beams using an optical parametric oscillator (“OPO”), then generate harmonics of these tunable beams. Other lasers mix the tunable beam with fixed wavelengths derived from the pump laser to reach the desired output wavelength.

Abstract: A method and apparatus for transferring information of an optical information-bearing signal from a first wavelength to a second wavelength. The method is implemented in an all-optical wavelength converter circuit which includes a laser diode in communication with a polarization controller. An information-bearing signal having a first wavelength is input to the circuit. A polarization controller adjusts the polarization of the information-bearing signal. The laser diode receives the polarization-adjusted information-bearing signal and generates a converted information-bearing signal by transferring the information of the polarization-adjusted information-bearing signal from the first wavelength to the second wavelength. The polarization controller receives the converted information-bearing signal from the laser diode, and polarizes the converted information-bearing signal.

Abstract: A recirculating delay line that includes an optical delay circuit generates repetitions of an input signal waveform that is of limited time duration.

Abstract: A voltage controlled oscillator is provided. The oscillator includes a surface acoustic wave element for forming a feedback circuit for an amplifier, and a phase adjustment circuit including a filter which is interposed in the feedback circuit. The oscillator also has a phase shifter including a hybrid coupler to which an additional control part is attached for changing a phase value within an oscillation loop with a control voltage supplied from an external source. An equal power divider equally distributes output power within the oscillation loop and supplies the output power outside the oscillation loop. A multi-layer board is used for mounting the amplifier, surface acoustic wave element, phase adjustment circuit, phase shifter, and equal power divider in at least two separate layers.

Abstract: One embodiment of the present invention is an optical delay line that comprises a plurality of optical elements in optical communication with each other, wherein: (a) at least one of the plurality of optical elements is capable of spatially dispersing a spectrum of an optical signal to provide a spatially dispersed optical signal; (b) at least one of the plurality of optical elements is adjustable to affect one or more of a phase delay and a group delay of an optical signal; and (c) at least one of the plurality of optical elements compensates for polarization introduced into the optical signal by others of the optical elements.

Abstract: A method and apparatus for harmonically upconverting a phase and/or amplitude modulated subcarrier signal to a higher frequency through a non-linear optical link is disclosed. The method requires that a bandpass signal, with a carrier frequency at a submultiple of the desired radio transmission frequency, be frequency translated in a non-linear two-port device. To avoid the inherent distortion inflicted on the information signal in harmonic upconversion, a predistortion technique is outlined. This consists of phase compression in the case of a phase modulated signal, amplitude scaling in the case of amplitude only and combined phase-amplitude predistortion for QAM type signals. With predistortion on the subcarrier signal input to the non-linear two-port, the resulting upconverted signal may be transmitted in a standard form suitable for demodulation at the signal destination without special equipment.

Abstract: An optical wavelength converting apparatus for use with a light source providing a light beam having a wavelength &lgr;, the apparatus comprises an optical wavelength conversion module and a wavelength controller. The optical wavelength conversion module comprises at least two optical modulators each capable of being coupled to the light source and respectively capable of modulating the light beam to a first modulated light beam including a pair of channel having wavelengths &lgr;±&Dgr;&lgr;i, and a second modulated light beam including a pair of channels having wavelengths &lgr;±&Dgr;&lgr;j where &Dgr;&lgr;i≠&Dgr;&lgr;j,. The wavelength controller is adapted for switching the light beam to one of said at least two optical modulators for modulation to one of said modulated light beams having a pair of channels with wavelengths &lgr;±&Dgr;&lgr;i or &lgr;±&Dgr;&lgr;j.

Abstract: An apparatus for performing high speed scanning of an optical delay and its application for performing optical interferometry, ranging, and imaging, including cross sectional imaging using optical coherence tomography, is disclosed. The apparatus achieves optical delay scanning by using diffractive optical elements in conjunction with imaging optics. In one embodiment a diffraction grating disperses an optical beam into different spectral frequency or wavelength components which are collimated by a lens. A mirror is placed one focal length away from the lens and the alteration of the grating groove density, the grating input angle, the grating output angle, and/or the mirror tilt produce a change in optical group and phase delay. This apparatus permits the optical group and phase delay to be scanned by scanning the angle of the mirror. In other embodiments, this device permits optical delay scanning without the use of moving parts.

Abstract: A photonic band gap structure device and method for delaying photonic signals of a predetermined frequency and a predetermined bandwidth by a predetermined delay is provided. A Fabry-Perot delay line device has several regions of periodically alternating refractive material layers which exhibit a series of photonic band gaps and a periodicity defect region, interposed between the regions of periodically alternating refractive material layers. The Fabry-Perot delay line device imparts a predetermined delay to photonic signals that pass therethrough. The introduction of the periodicity defect region into this photonic band gap structure creates a sharp transmission resonance within the corresponding photonic band gap of the structure and causes at least an order of magnitude improvement in photonic signal delay for a band-edge delay line device of similar size. Variable photonic delays to multiple photonic signals are also generated by this Fabry-Perot delay line device.

Abstract: A method and apparatus for data conversion using time manipulation is disclosed. Ultrafast analog-to-digital (A/D) conversion and digital-to-analog I/A) conversion are achieved by optoelectronic time-stretching or time-compression, respectively. A pulsed laser is chirped by frequency spreading the laser output in either discrete or continuous fashion. The chirped output is then modulated with the electrical signal, and then frequency spread again. The output of the modulated signal is detected with a photodetector to convert the optical signal to a time-manipulated copy of the electrical signal.

Abstract: An apparatus for performing high speed scanning of an optical delay and its application for performing optical interferometry, ranging, and imaging, including cross sectional imaging using optical coherence tomography, is disclosed. The apparatus achieves optical delay scanning by using diffractive optical elements in conjunction with imaging optics. In one embodiment a diffraction grating disperses an optical beam into different spectral frequency or wavelength components which are collimated by a lens. A mirror is placed one focal length away from the lens and the alteration of the grating groove density, the grating input angle, the grating output angle, and/or the mirror tilt produce a change in optical group and phase delay. This apparatus permits the optical group and phase delay to be scanned by scanning the angle of the mirror. In other embodiments, this device permits optical delay scanning without the use of moving parts.

Abstract: A photonic band gap structure device and method for delaying photonic signals of a predetermined frequency and a predetermined bandwidth by a predetermined delay is provided. A Fabry-Perot delay line device has several regions of periodically alternating refractive material layers which exhibit a series of photonic band gaps and a periodicity defect region, interposed between the regions of periodically alternating refractive material layers. The Fabry-Perot delay line device imparts a predetermined delay to photonic signals that pass therethrough. The introduction of the periodicity defect region into this photonic band gap structure creates a sharp transmission resonance within the corresponding photonic band gap of the structure and causes at least an order of magnitude improvement in photonic signal delay for a band-edge delay line device of similar size. Variable photonic delays to multiple photonic signals are also generated by this Fabry-Perot delay line device.

Abstract: An optical frequency shifter which has no insertion loss polarization dependency and no polarization mode dispersion is formed by: at least one ultrasonic wave generator for generating ultrasonic waves; at least one electric acousto-optic element forming at least one diffraction grating therein upon being applied with the ultrasonic waves generated by the ultrasonic wave generator; at least one polarization rotator for rotating a polarization plane of a first primary diffracted light produced by the diffraction grating, by 90.degree.

Abstract: An optical frequency sweep signal generator using an optical frequency variable bandpass filter which can be practically used is provided.

Abstract: An optical switch network which includes a plurality N of cascaded optical switching stages, each mth one of the switching stages including 2.sup.m-1 Mach-Zehnder interferometers, where m=1 through N. The input port of the Mach-Zehnder interferometer of a first one of the optical switching stages receives an optical input signal, and the 2.sup.N-1 Mach-Zehnder interferometers of the Nth one of the optical switching stages provide a total of 2.sup.N output ports. Each of the Mach-Zehnder interferometers is preferably an unbalanced Mach-Zehnder interferometer, and the optical input signal preferably has a wavelength which is a selected one of 2.sup.N selectable wavelengths. The plurality N of cascaded optical switching stages provide 2.sup.N possible optical paths, whereby the optical input signal is automatically routed along a selected one of the 2.sup.N possible optical paths in dependence upon its selected wavelength.

Abstract: Optical communication systems, optical computing systems and optical logic elements which rely on the phenomina of cross-phase modulation to alter and control, either or simultaneously, the spectral, temporal or/and spatial properties of ultrashort light pulses for processing information with high speed repetition rates. A weak beam of ultrashort light pulses is modulated by an intense beam of ultrashort light pulses by copropagating both beams through a non-linear medium such that cross-phase modulation effects are realized.