Abstract: In one embodiment, a laser module comprising an optical element, a frequency converter, a selective reflector, and one or more surface-emitters, each coupled to a common substrate, wherein the emitters, the optical element, the frequency converter, and the selective reflector are positioned with respect to each other such that at least a portion of the coherent light emitted from the surface-emitters travels through the optical element, through the frequency converter and through the selective reflector. In a method embodiment, a method for frequency converting light generated by a surface-emitter, wherein the light passes through an optical element, a frequency converter, and a selective reflector, each coupled to a common substrate.

Abstract: A nonlinear fiber having a third-order nonlinear coefficient of at least 30 W?1km?1, and its cladding containing Er or Tm at a portion within 3 ?m from the interface with its core. A wavelength conversion method of making a signal light having a wavelength ?S and an intensity IS and a pump light having a wavelength ?P which is shorter than 2?S and an intensity higher than IS enter a nonlinear fiber 1, and generating a converted light having a wavelength ?C of ?S?P/(2?S??P) and an intensity IC by four wave mixing, wherein Er or Tm is present in the cladding at a portion with a diameter in the nonlinear fiber 1 of at most the mode field diameter, and the converted light is generated by four wave mixing while Er or Tm is excited by an excitation light.

Abstract: A wavelength converting element is provided in which a fundamental wave with respect to an optical crystal substrate and a peak of a vertical transverse mode of a second harmonic are made to coincide, the converting efficiency is good, and a beam shape which enables good joining to a lens or an optical fiber is obtained. Given that an angle formed by a surface of the optical crystal substrate and a C axis of the optical crystal substrate is ?, a period at which inverted domains are formed is p, and a distance from a distal end of a comb-shaped electrode for forming the inverted domain to a central position of a waveguide is G, in the ion implantation, a concentration peak of the ion implantation is formed at a distance of substantially (G·tan ?+p/4) from the surface of the optical crystal substrate.

Abstract: A manufacturing method for quasi phase matching (QPM) wavelength converter elements using crystal quartz as a base material in which twins are periodically induced, comprises a step of periodically inducing the twins by applying a stress onto a crystal quartz substrate as the base material so that an angle ? of a direction in which the stress is applied relative to a Z axis of the crystal quartz is 60°<?<90°.

Abstract: A method of using a carbon nanotube assembly comprising: arranging a signal responsive array of nanotubes on a substrate, and heterodyning a signal processed by the array of nanotubes on the substrate.

Abstract: An optical frequency mixer according to one embodiment of the present invention comprises a V-shaped resonant cavity including a first reflective surface, a second reflective surface and an output coupler, a pumping unit configured to emit a pumping wave to the laser gain medium to generate a resonating wave in the resonant cavity, a nonlinear crystal positioned on an optical path of the resonating wave in the resonant cavity, and an input interface configured to emit a mixing wave into the resonant cavity. Preferably, the output coupler can be a plano-concave lens having a concave surface configured to reflect the resonating wave and to focus the resonating wave such that the spot size of the resonating wave is matched the spot size of the pumping wave. Particularly, the nonlinear crystal is positioned between the output coupler and the input interface.

Abstract: A wavelength conversion module according to the present invention includes an external resonator, a semiconductor laser module and a wavelength conversion device for converting a wavelength of light output from the semiconductor laser module into a shorter wavelength. This wavelength conversion device includes at least one of a nonlinear crystal for generating SFG (Sum-frequency Generation) light and a nonlinear crystal for generating SHG (Second Harmonic Generation) light. Each of the SFG generating element and the SHG generating element of the wavelength conversion device may have a periodically-poled ridge-waveguide structure or a periodically-poled proton-exchanged-waveguide structure.

Abstract: A measured optical pulse and a sampling optical pulse having different wavelengths are input to a nonlinear optical effect, that is, (i) a nonlinear optical medium generating four optical wave mixing or three optical wave mixing, and the optical intensity of the wavelength converted light generated by the four optical wave mixing or four optical wave mixing generated in a common portion in time of the two optical pulses is detected, thereby observing the waveform of a measured light, or (ii) a nonlinear optical medium generating mutual phase modulation which generates mutual phase modulation, and the optical intensity of converted light switched using a phase shift by mutual phase modulation generated in a common portion in time is detected, thereby observing the waveform of measured light.

Abstract: A wavelength converter device is provided for generating a converted radiation at frequency ?g through interaction between at least one signal radiation at frequency ?s and at least one pump radiation at frequency ?p, including an input for the at least one signal radiation at frequency ?s, a pump light source for generating the at least one pump radiation at frequency ?p, an output for taking out the converted radiation at frequency ?g, a structure for transmitting the signal radiation, including two optical resonators having a non-linear material, having an optical length of at least 40*?/2, ? being the wavelength of the pump radiation, and resonating at the pump, signal and converted frequencies ?p, ?s and ?g, wherein by propagating through the structure, the pump and signal radiation generate the converted radiation by non-linear interaction within the optical resonators.

Abstract: A plural wavelength light beam source may include one or more integrated laser diodes and a wavelength-conversion source such as a second harmonic generation laser. According to some embodiments the one or more laser diodes may be aligned to emit light through a wavelength converter. According to some embodiments, a polarizer for selecting a pump wavelength polarization delivered to the wavelength converter may include a beam combining structure.

Abstract: An optical frequency converter that can use a low-amplitude, high-frequency signal for converting a wide range of optical frequencies. The optical frequency converter includes a device for modulating a lightwave of a preset frequency with a modulation signal to generate a group of sidebands thereof, a device for selecting sidebands from among the group of sidebands, and a device for changing modulation signal frequencies and selecting specific sidebands.

Abstract: Techniques for reconfiguring spectral features stored in a medium based on a two-state atomic system with transition dipole moment ? includes causing a chirp to pass into the medium. The chirp includes a monochromatic frequency that varies in time by a chirp rate ? over a frequency band BR during a time interval TR. The amplitude AR of the chirp is constant over BR and equal to AR=(hbar/??)?{square root over ((? ln [2/?]))}, The term hbar is reduced Plank's constant, ln is a natural logarithm function, and ? is a ratio of a circumference of a circle to a diameter of the circle. For ?<<1, the atomic-state populations in the two states are inverted. For ?=1, prior atomic-state populations are erased, with final populations equal in the two states, regardless of populations before erasure.

Abstract: Optical frequency conversion by four-wave mixing in a fiber is considered. If the frequencies and polarizations of the waves are chosen judiciously, four-wave mixing enables the translation of individual and entangled states, without the noise pollution associated with parametric amplification (modulation instability or phase conjugation) and with reduced noise from stimulated Raman scattering.

Abstract: An inspection system may be configured to inspect objects, such as semiconductor wafers, using narrow-pulse broadband illumination. The illumination may be obtained in some embodiments using a laser configured to emit light into a material having a spectral broadening effect. The inspection system can include various filters which may be selectively placed in the illumination and/or imaging path in order to tune the spectrum of light impinging on the wafer and the light that is detected. The filters may include selectable filters, fixed filters, and filters whose characteristics can be adjusted in-place. In some embodiments, filters may be used to match the illumination/detection spectra of different tools. Additionally, the broadband illumination may be tuned between inspections and/or during inspections for best results. The system may support Fourier filtering whereby light, related to repetitive features of the object and in one or more wavelength sub-bands of the illumination, may be filtered.

Abstract: An ultraviolet light source (1) comprises a laser light source (10) for generating a signal light in the infrared region, a optical amplifier (20) which comprises fiber optical amplifiers (21, 22) and amplifies the signal light generated by the laser light source (10), and a wavelength converting optical system (30) which coverts the signal light amplified by the light amplifier (20) into an ultraviolet light and outputs the converted light. The ultraviolet light source (1) uses a single-mode fiber laser (26) as an excitation light source for at least the fiber optical amplifier (22) at one stage of the optical amplifier (20).

Abstract: The present invention introduces a novel route toward microstructural orientation into organic films, using multiple hydrogen-bonding to self-assemble chromophore molecules into electro-optic films in a net polar orientation. High-quality, thick films (up to micrometers) with molecular net dipole orientations can be fabricated under vacuum in hours. The film microstructure is intrinsically acentric; and the orientation is robust.

Abstract: Quasi-phasematching design to provide an approximation to a desired spectral amplitude response A(f) is provided. An initial phase response ?(f) corresponding to A(f) is generated. Preferably, d2?(f)/df2 is proportional to A2(f). Alternatively, ?(f) can be a polynomial in f. A function h(x) is computed such that h(x) and H(f)=A(f)exp(i?(f)) are a Fourier transform pair. A domain pattern function d(x) is computed by binarizing h(x) (i.e., approximating h(x) with a constant-amplitude approximation). In some cases, the response provided by this d(x) is sufficiently close to A(f) that no further design work is necessary. In other cases, the design can be iteratively improved by modifying ?(f) responsive to a difference between the desired response A(f) and the response provided by domain pattern d(x). Various approaches for binarization are provided. The availability of multiple binarization approaches is helpful for making design trades (e.g.

Abstract: A fundamental laser beam is wavelength converted through nonlinear optical crystals by traveling in one direction, sequentially through two nonlinear optical crystals arranged in series. A wavelength-converted laser beam is generated and includes wavelength-converted laser beams having polarized directions differing from each other by angles in a range from 45° to 90°. The two nonlinear optical crystals have crystal orientation axes differing by 45° to 90° when viewed along the optical axis of the laser beam.

Abstract: A laser apparatus including a laser generating portion that generates pulse light having a single wavelength within a range from an infrared band to a visible band. An optical amplifier is optically connected to the laser generating portion, and includes a plurality of fiber optical amplifiers to amplify the pulse light a plurality of times. A wavelength converting portion is optically connected to the optical amplifier, and includes cylindrical lenses and a plurality of non-linear optical crystals to wavelength-convert the amplified pulse light into ultraviolet light. The amplified pulse light is incident on the cylindrical lenses through one of the plurality of non-linear optical crystals and is incident on a different one of the plurality of non-linear optical crystals from the one non-linear optical crystal through the cylindrical lenses.

Abstract: Quasi-phasematching design to provide an approximation to a desired spectral amplitude response A(f) is provided. An initial phase response ?(f) corresponding to A(f) is generated. Preferably, d2?(f)/df2 is proportional to A2(f). Alternatively, ?(f) can be a polynomial in f. A function h(x) is computed such that h(x) and H(f)=A(f)exp(i?(f)) are a Fourier transform pair. A domain pattern function d(x) can be computed by binarizing h(x) (i.e., approximating h(x) with a constant-amplitude approximation). In some cases, the response provided by this d(x) is sufficiently close to A(f) that no further design work is necessary. In some embodiments of the invention, the need for binarization can be reduced or eliminated by providing amplitude modulation of the effective nonlinearity.

Abstract: Wavelength combining for nonlinear frequency conversion is provided having nonlinear feedback to the sources being combined. Power that is fed back to the sources is obtained from within a wavelength conversion device. Therefore, the feedback power to a source has a nonlinear dependence on input power provided by that source to the wavelength conversion device. Such nonlinear feedback can advantageously reduce the sensitivity of the output power from the wavelength conversion device to variations in the nonlinear coefficients of the conversion device. The reason for this reduced sensitivity is that in preferred embodiments, the feedback power increases if a nonlinear coefficient decreases. This increased feedback tends to increase the power supplied to the conversion device, thus mitigating the effect of the reduced nonlinear coefficient.

Abstract: An optical device for optical communication includes a first main electrode disposed between a first splitter and a second splitter on a first arm. A first auxiliary electrode is disposed between the second splitter and a third splitter on the first arm. A second main electrode and a second auxiliary electrode are disposed between a third splitter and a fourth splitter on a second arm. The second main electrode is provided on the second arm at the first port side, and the second auxiliary electrode is provided on the second arm at the second port side. By such disposition of the first and second auxiliary electrodes, input signal light applied through a third port or a fourth port acts on the first main electrode prior to the first and second auxiliary electrodes. Therefore, the input signal light will not be affected by the first and second auxiliary electrodes.

Abstract: A band gap discontinuity is propagated across a Photonic Crystal (PC) to capture thermal energy in a region near the primary emission wavelength of the Planck spectral distribution and transfer that energy to a different spectral region where it is emitted. To extend the range of frequency shifting beyond the width of a single band gap, the intrinsic control parameters (e.g., lattice geometry factors, scattering element geometric factors, and variations in the index of refraction) are spatially varied across the PC to form a band gap gradient. Propagation of the band gap discontinuity, starting in the infrared wavelength region where the thermally generated electromagnetic energy is concentrated and propagating towards the long wavelength region, locally captures the thermal electromagnetic radiation, shifts it downwards in frequency, and pushes the lower-frequency thermal electromagnetic radiation on to the next region. The same principles apply to shift the frequency to shorter wavelengths.

Abstract: A semiconductor-based all optical wavelength converter is disclosed. An apparatus according to aspects of the present invention includes an optical waveguide disposed in semiconductor material. An optical pump source is optically coupled to direct an optical pump beam having a first wavelength into the optical waveguide. The optical waveguide is further optically coupled to receive an input optical beam having a second wavelength. The optical waveguide is optically coupled to generate an output optical beam having a third wavelength in response to the optical pump beam and the input optical beam in the optical waveguide. A diode structure is disposed in the optical waveguide. The diode structure includes at least P and N regions. The diode structure is biased to generate an electric field to remove free carriers from an optical path through the optical waveguide generated in response to two photon absorption in the optical waveguide.

Abstract: A phase optimization apparatus and method to obtain a maximum extinction ratio by feeding back a portion of an optical signal output from a Mach-Zehnder interferometer wavelength converter using XPM of a semiconductor optical amplifier to maintain an optimum phase difference between two arms. The phase optimization apparatus includes a first arm having a first semiconductor optical amplifier that amplifies a pump signal and a probe signal, a second arm having a second semiconductor optical amplifier that amplifies the probe signal, and a ? phase shifter that controls the phase of the amplified signal, an optical band-pass filter that filters optical signals to output only the modulated probe signal; and a phase control unit that receives feedback to output to the ? phase shifter of the second arm a phase control signal, which controls a phase difference between the first and second arms.

Abstract: WDM optical signals are amplified using optical parametric amplification by applying an appropriate separation of those optical signals according to their carrier angular frequencies. These angular frequencies are within the two principal amplification bands defined by the non-linear optical medium used for optical parametric amplification. It is advantageously proposed to launch into the non-linear optical medium in one direction the optical signals of carrier frequencies within the one amplification band, and in the opposite counter-propagating direction the optical signals of carrier angular frequencies within the other amplification band. The required pump radiation is launched co-linearly with the respective optical signals to be amplified.

Abstract: A wavelength-doubling optical parametric oscillator (OPO) comprising a type II nonlinear optical medium for generating a pair of degenerate waves at twice a pump wavelength and a plurality of mirrors for rotating the polarization of one wave by 90 degrees to produce a wavelength-doubled beam with an increased output energy by coupling both of the degenerate waves out of the OPO cavity through the same output coupler following polarization rotation of one of the degenerate waves.

Abstract: The invention related to a photochromic polymeric composition comprising a polymer matrix and a photochromic compound which is an adduct comprising a photochromic moiety and at least one pendant oligomer group to provide a rate of fade of the photochromic polymeric composition which is significantly changed when compared with the corresponding composition comprising the photochromic compound without said pendent oligomer. The invention also relates to a photochromic compound which is an adduct comprising a photochromic moiety and at least one pendent oligomer.

Abstract: An imaging system, methodology, and various applications are provided to facilitate optical imaging performance. The system includes a sensor having one or more receptors and an image transfer medium to scale the sensor and receptors in accordance with resolvable characteristics of the medium. A computer, memory, and/or display associated with the sensor provides storage and/or display of information relating to output from the receptors to produce and/or process an image, wherein a plurality of illumination sources can also be utilized in conjunction with the image transfer medium. The image transfer medium can be configured as a k-space filter that correlates a pitch associated with the receptors to a diffraction-limited spot associated with the image transfer medium, wherein the pitch can be unit-mapped to about the size of the diffraction-limited spot.

Abstract: The present invention relates a wavelength conversion apparatus capable of making the wavelength of output light constant even when the wavelength of input light is changed. The wavelength conversion apparatus comprises a first wavelength converter and a second wavelength converter which are provided in series between an input terminal and an output terminal. The first wavelength converter generates four-wave mixing by input light and a first pumping light, generates an intermediate light having a new wavelength by the four-wave mixing, and outputs the intermediate light and the input light. The second wavelength converter generates four-wave mixing by the intermediate light and the input light, respectively outputted from the first wavelength converter, and a second pumping light, generates output light having a new wavelength by the four-wave mixing, and outputs the generated output light.

Abstract: A integrated optical circuit comprises an interferometer having a first optical path and a second optical path configured for regenerating an input signal entering the first path by interference at a first coupler between continuous wave (CW) signals from the two optical paths, and a third optical path configured such that a canceling signal passing therethrough cancels, at a second coupler, a traveling signal from the first arm. When the device is operated in a counter-propagative mode, the traveling signal is the CW signal from the first arm. When the device is operated in a co-propagative mode, the traveling signal is the input signal from the first arm.

Abstract: An optical waveguide device has a substrate composed of a nonlinear optical material and a periodically domain-inverted structure having the same composition as the nonlinear optical material, where the domain-inverted structure has a refractive index distribution relying on the domain-inverted structure.

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: In an optical wavelength converting method in which light from a laser oscillator that oscillates coherent light of an inherent wavelength ? is employed as incident light, and is made to input to a nonlinear optical crystal, and light having a wavelength of ½? is radiated, the wavelength of the incident light is 1000 nm or less, and the peak power density of the incident light is 0.1–10 fold greater than the peak power density that provides the maximum conversion efficiency. The nonlinear optical crystal is heated to and maintained at 200–600° C. Prescribed fundamental waves are input to a first crystal and a second crystal sequentially. The first crystal has a higher bulk damage threshold value with respect to the fundamental waves than that of the second crystal. The second crystal has a higher effective nonlinear constant with respect to the fundamental waves than that of the first crystal.

Abstract: A photonic bandgap assembly used in a laser device for generating a near-diffraction-limited optical beam that comprises simultaneous multiple wavelengths. The photonic bandgap fiber assembly has a plurality of serially connected segments each having a photonic crystal fiber each being designed to efficiently perform Raman conversion on a pump wavelength to a near-diffraction-limited output wavelength. A first segment of the assembly is connected to a pump laser, and the output wavelength generated by each segment is output to the following segment to serve as a pump beam of the photonic crystal fiber thereof. Therefore, the pump beam is converted in a plurality of output beams with different wavelengths. The output beams can then be selectively recombined and coupled out as a multiple-wavelength optical beam.

Abstract: An ultraviolet laser is provided that increases the conversion efficiency of laser beams when harmonics having wavelengths of less than 355 nm are generated by converting laser beams with a wavelength conversion element made of a single crystal of lithium tetraborate. A wavelength conversion element is heated and controlled to a specific temperature (for example, 200° C.) within a temperature range of 200 to 450° C. with a predetermined temperature precision.

Abstract: A laser apparatus that includes a laser light generation section, an optical amplification section, a wavelength conversion section and a suppressing section is provided. The laser light generation section includes a single wavelength oscillatory laser and generates pulsed light having a single wavelength within a wavelength range ranging from about 1.51 to 1.59 ?m. The optical amplification section includes an optical fiber amplifier and is optically connected to the laser light generation section to amplify the pulsed light. The wavelength conversion section includes a nonlinear optical crystal and is optically connected to the optical amplification section to perform wavelength conversion of the amplified pulsed light into ultraviolet light. The suppressing section suppresses expansion of a wavelength width of light originated in a nonlinear effect of an optical element between the single wavelength oscillatory laser and the wavelength conversion section.

Abstract: Provided is a resonant cascaded difference frequency generator that is capable of improving the conversion efficiency of the second-order nonlinear optical phenomena by resonating the second harmonic wave of a pump light. The resonant cascaded difference frequency generator includes: a nonlinear medium, which receives a pump light and a signal light and then generates the second harmonic wave of the pump light through second harmonic generation, in a cascaded way generates a converted light of a difference frequency through difference frequency generation between the signal light and the second harmonic wave; and a resonant structure that resonates the second harmonic wave of the pump light on the basis of the nonlinear medium.

Abstract: A wavelength converter that is used in an optical communication system utilizing wavelength multiplexing. The wavelength converter has a quasi-phase matched quartz crystal that has a second-order nonlinear effect, and a light coupling device that mixes the signal light and control light and inputs this mixed light into the quasi-phase matched quartz crystal. The wavelength converter also has quartz type optical fibers between the light coupling device and the quasi-phase matched quartz crystal. The mode diameter of the quartz type optical fibers is substantially the same as the mode diameter of the optical waveguide.

Abstract: The invention relates to a device for the production of tuneable light impulses in a visible spectral range, comprising a laser system (LS) which emits femtosecond light impulses in the infrared spectral range, and an optical frequency converter (FC) for converting the wave lengths of the light impulses into the visible spectral range. According to the invention, the wave length of the light impulse emitted by the laser system can be tuned in order to provide said type of device which can be used as a light source for time-resolved fluorescence spectroscopy. Said device also comprises an optical stretcher which enables the duration of the impulse of the frequency converted light impulse to be increased to at least 1 ps.

Abstract: Methods and specialized media adapted to the formation of a steady-state, non-equilibrium distribution of free carriers using mesoscopic classical confinement. Specialized media is silicon-based (e.g., crystalline silicon, amorphous silicon, silicon dioxide) and formed from mesoscopic sized particles embedded with a matrix of wide-bandgap material, such as silicon dioxide. An IR to visible light imaging system is implemented around the foregoing.

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: Up-conversion and down-conversion photo-luminescence in rare earth compounds are disclosed. Broadband, super-radiant, and discrete line emissions are observed. The rare earth compounds include a rare earth element and at least one other element selected from chalcogens, halogens, nitrogen, and phosphorus. The rare earth compounds include, but are not limited to, rare earth oxides, fluorides, and oxyfluorides. Doping and co-doping of rare earth compounds in an optical host material is not required. The compounds are irradiated with incident light having an incident wavelength that is selected to be highly absorbed by the rare earth compound. The up-conversion and down-conversion luminescence have been observed which may be caused by unknown electron transitions, particularly in the case of ytterbia.

Abstract: The invention relates to novel mono-, oligo and poly[2,3-b]-thienothiophenes, their use as semiconductors or charge transport materials, in optical, electro-optical or electronic devices like for example liquid crystal displays, optical films, organic field effect transistors (FET or OFET) for thin film transistor liquid crystal displays and integrated circuit devices such as RFID tags, electroluminescent devices in flat panel displays, and in photovoltaic and sensor devices, and to a field effect transistor, light emitting device or ID tag comprising the novel polymers.

Abstract: A photosensitive resist layer is formed on one surface of a single-polarized ferroelectric substance having nonlinear optical effects. The resist layer has properties such that, when light is irradiated to the resist layer, only exposed areas of the resist layer or only unexposed areas of the resist layer become soluble in a developing solvent. The resist layer is then exposed to near-field light in a periodic pattern with a device, which receives exposure light and produces the near-field light in the periodic pattern. The resist layer is then developed to form a periodic pattern. A periodic electrode is then formed on the one surface of the ferroelectric substance by utilizing the periodic pattern of the resist layer as a mask, the periodic electrode being formed at positions corresponding to opening areas of the mask.

Abstract: A terahertz wave-generating semiconductor crystal includes a zincblende-type III-V compound semiconductor crystal that generates terahertz wave pulses upon application of an ultrashort light pulse in the optical communication band serving as a pump beam.

Abstract: Two grooves 10 are diced in parallel along the light passage direction in a quartz quasi-phase matching element 1. Consequently, as is shown in (b) and (c), a protruding part 11 which is positioned between the two grooves 10 is formed on the upper surface side (in the figures), and a ridge type waveguide 9 is formed inside this protruding part. Accordingly, if light is caused to pass through this ridge type waveguide 9, the light can be caused to pass through the portions with inverted crystal axes (polarization inversion regions) 4, and can be subjected to a wavelength conversion, in a state in which the light is confined into the ridge type wavelength guide 9. As a result, a state can be produced in which the energy of the light is high inside the wavelength conversion region, so that a high wavelength conversion efficiency can be obtained.

Abstract: A white light source has a light emission device, in particular an IR laser diode, whose emitted radiation beam is converted, in a nonlinear-optical element and a conversion element, into a radiation beam with wavelengths ?1, . . . ?n which can be perceived as white light and can have a higher power rating.

Abstract: A high-efficiency multiple-pass nonlinear wavelength converter and amplitude modulator employs a variable dispersion element between adjacent passes of a nonlinear wavelength conversion process in a single nonlinear optical material substrate. When controlled by a voltage via the electro-optic effect, the variable dispersion element dynamically alters the phase matching condition of the multiple-pass nonlinear wavelength conversion process and thus modulates the laser output amplitude. When the phase mismatch between passes is completely compensated by the variable dispersion element, the multiple-pass nonlinear wavelength converter achieves its maximum efficiency.

Abstract: A phasor can be employed within the resonator of an optical parametric oscillator (OPO) to adjust the absolute and relative phase of OPO beams. An embodiment of the invention comprises an OPO having at least one phasor for receiving and adjusting the phase of one or more beams resonating within the optical cavity which forms part of the OPO. Smooth alteration of the phases of the OPO beams using the at least one phasor facilitates continuous tuning of the wavelength of at least one of the beams. In another embodiment, the at least one phasor may be a translatable wedge or have adjustable refractive index to alter the phases of the OPO beams. In an additional embodiment, each at least one phasor may be comprised of more than one material, held fixedly together.