Abstract: A wavelength conversion device in this disclosure may include: a nonlinear crystal including a first surface; a first film to be joined to the first surface and including at least one layer; and a first prism to be joined to the first film.

Abstract: Methods, apparatus and systems for an up-converter resonant cavity light emitting diode device includes a semiconductor light source, an up-converter to form the light emitter with up-converting materials and an electrical source coupled with the semiconductor light source for providing electrical energy to the semiconductor light source to provide a desired wavelength emitted light. The semiconductor light source is a resonant cavity light emitting diode or laser that emits an approximately 975 mm wavelength to provide electrical and optical confinement to the semiconductor light source to form a resonant cavity up-converting light emitting diode (UC/RCLED). Rows and columns of electrodes provide active matrix addressing of plural sets of UC/RCLEDs for display devices.

Abstract: An optical device comprising a tunable optical frequency comb generator. The comb generator includes an interferometer, and an optical feed-back loop waveguide and an electronic controller.

Abstract: A beam adjuster assembly (14) receives an input beam (16) and provides a first output beam (18) and a spaced apart second output beam (20). The beam adjuster assembly (14) comprises a first frequency adjuster (22) and a second frequency adjuster (24). The first frequency adjuster (22) receives the input beam (16). The first frequency adjuster (22) transmits a first portion of the input beam (16) to provide the first output beam (18) having a first output frequency. Additionally, the first frequency adjuster (22) adjusts a second portion of the input beam (16) to provide a first adjusted beam (354). The second frequency adjuster (24) receives the first adjusted beam (354). Moreover, the second frequency adjuster (24) adjusts at least a portion of the first adjusted beam (354) to provide the second output beam (20) having a second output frequency that is different than the first output frequency.

Abstract: A light source including a light emitting unit, a nonlinear medium, and a resonant grating. The light emitting unit is arranged to emit a first light into the nonlinear medium. The nonlinear medium is arranged to generate a second light such that an optical frequency of the second light is higher than an optical frequency of the first light. The resonant grating is arranged to stabilize an optical frequency of the first light by providing optical feedback to the light emitting unit.

Abstract: A wavelength conversion element is provided as one including a monocrystalline nonlinear optical crystal. The nonlinear optical crystal has: a plurality of first regions having a polarity direction along a predetermined direction; a plurality of second regions having a polarity direction opposite to the predetermined direction; an entrance face into which a fundamental incident wave having a wavelength ? and a frequency ? is incident in a direction substantially perpendicular to the predetermined direction; and an exit face from which a second harmonic with a frequency 2? generated in the crystal emerges. The plurality of first and second regions are formed as alternately arranged in a period substantially equal to d expressed by a predetermined expression, between the entrance face and the exit face.

Abstract: A light conversion module includes a coupler for combining two light beams to form a combined light beam, a nonlinear crystal arranged to receive the combined light beam and configured to include a plurality of poling regions for performing successive nonlinear frequency mixing processes, a first optical device configured to focus the combined light beam onto the nonlinear crystal, a first moving stage carrying the nonlinear crystal and moving the nonlinear crystal for an adjustment of a focus position of the combined light beam on the nonlinear crystal, and an optical detector configured for measuring a power level of the light beam from the nonlinear crystal for the adjustment of the focus position of the combined light beam on the nonlinear crystal.

Abstract: A method for operating a wavelength-converted light source includes directing a pump beam having a fundamental wavelength from the laser source into an input facet of the wavelength conversion device such that a wavelength-converted output beam is emitted from an output facet of the wavelength conversion device in the field of view of an optical detector. A physical property of the wavelength conversion device is varied within individual ones of a succession of consecutive speckle reduction intervals having durations less than the integration time of the optical detector. The physical property of the wavelength conversion device is varied by an amount that is sufficient to change in a phase-matched (PM) wavelength of the wavelength conversion device. The fundamental wavelength of the pump beam is thereafter adjusted based on the change in the PM wavelength to maintain an efficiency of the wavelength conversion in the wavelength conversion device.

Abstract: A wavelength conversion element having an improved property-maintaining life and a method for manufacturing the wavelength conversion element are provided. A wavelength conversion element 10a has an optical waveguide 13. The wavelength of incoming light 101 input from one end 13a of the optical waveguide 13 is converted and outgoing light 102 is output from the other end 13b of the optical waveguide 13. The wavelength conversion element includes a first crystal 11 composed of AlxGa(1-x)N (0.5?x?1); and a second crystal 12 having the same composition as that of the first crystal. The first and second crystals 11 and 12 form a domain-inverted structure in which a polarization direction is periodically reversed along the optical waveguide 13, and the domain-inverted structure satisfies quasi phase matching conditions with respect to the incoming light 101. At least one of the first and second crystals has a dislocation density of 1×103 cm?2 or more and less than 1×107 cm?2.

Abstract: A light emitting apparatus has a radiation source for emitting short wavelength radiation. A down conversion material receives and down converts at least some of the short wavelength radiation emitted by the radiation source and back transfers a portion of the received and down converted radiation. An optic device adjacent the down conversion material at least partially surrounds the radiation source. The optic device is configured to extract at least some of the back transferred radiation. A sealant substantially seals a space between the radiation source and the optic device.

Abstract: The invention relates to a laser system including a nonlinear crystal having a first length portion and a second length portion. The nonlinear crystal disposed to receive input light from the laser for converting the input light into frequency converted light; wherein the nonlinear crystal is configured so that the first length portion of the nonlinear crystal is phase matching for the input light and the frequency converted light, and the second length portion of the nonlinear crystal is phase mismatching for the input light and the frequency converted light. Phase mismatching means may include a temperature controlling board, a clamp, or electrodes.

Abstract: A High-power sum frequency generator system including a first electromagnetic source for generating a first fundamental field and a second fundamental field emitted along a propagation path, and a first nonlinear component and a second nonlinear component arranged in series along the propagation path. The first nonlinear component generates a first sum frequency field from the first fundamental field and the second fundamental field, the first sum frequency field having a first polarization. The second nonlinear component generates a second sum frequency field from the first and second fundamental fields, the second sum frequency field having a second polarization. The system has an output that includes the first sum frequency field and the second sum frequency field, and a direction of the first polarization forms a mutual angle with a direction of the second polarization such that the two polarizations are non-parallel.

Abstract: An optical crystal includes a first non-linear optical crystal that generates terahertz waves corresponding to a difference frequency component in incident light with two different wavelengths by a difference frequency generation, and a second non-linear optical crystal that generates terahertz waves corresponding to a difference frequency component in incident light with two different wavelengths by a difference frequency generation, the second non-linear optical crystal being different in material from the first non-linear optical crystal, and the first non-linear optical crystal and the second non-linear optical crystal being disposed in contact or close together.

Abstract: The present invention relates to a potassium chloroborate nonlinear optical crystal, a preparation method and a use thereof. The crystal has a chemical formula of K3B6O10Cl, has no symmetric center, belongs to rhombohedral crystal system, has a space group R3m with unit cell parameters of a=10.0624(14) ?, b=10.0624(14) ?, c=8.8361(18) ?, Z=3 and V=774.8(2) ?3. It has a powder second harmonic generation efficiency of about 3 times that of KDP (KH2PO4), and a Mohs hardness of 4-5, a transparent wavelength range of 165 nm-3460 nm. The compound is synthesized by a solid-state reaction and the crystal is grown by using a flux, which are of easy operation and low costs. The obtained crystal has large size, short growing period, little inclusion, relatively high mechanical hardness, and is easy to be cut, polished and stored. Said crystal is used to generate a second, third, fourth or fifth harmonic light output for a laser beam with a wavelength of 1064 nm.

Abstract: A light-emitting device for emitting light having a desired color point, comprising at least one solid-state light source (1), at least one light-converting element (5), a light guiding arrangement (2) and a switch control unit (4), wherein the solid-state light source (1) is provided for emitting primary radiation (20), the light guiding arrangement (2) arranged between the solid-state light source (1) and the light-converting element (5) has at least one electro-optical switch (31) for controllably splitting the primary radiation (20) into a first portion (21) and a second portion (22), the switch control unit (4) is provided for controlling the electro-optical switch or switches (31) for variably adjusting the ratio between the first (21) and the second portion (22) of the primary radiation (20), and the light-converting element (5) is provided for the partial or complete absorption of at least a first portion (21) of the primary radiation (20) and for the re-emission of secondary radiation.

Abstract: As a spatial light modulator 35 is disposed between a wavelength conversion part 315 and an exit surface 311b in a ferroelectric crystal substrate 31, only zeroth-order light which is at a particular wavelength is guided to a substrate while laser light from the wavelength conversion part 315 is being modulated, whereby a pattern corresponding to LSI data is drawn. Further, the spatial light modulator 35 is disposed together with the wavelength conversion parts 314 and 315 inside the ferroelectric crystal substrate 31.

Abstract: The invention relates to a device, system, and method for optimizing and altering electromagnetic frequency using Doppler shifts of electromagnetic radiation, and, in particular, optimizing frequency for application to photovoltaic devices and the like. The device comprises a crystal positioned in a channel undergoing a vibration, wherein an interaction between an incoming electromagnetic radiation and the vibration of the crystal optimizes a frequency of electromagnetic radiation.

Abstract: The invention provides an apparatus and method for generating quantum-correlated and/or polarization-entangled photon pairs with unequal wavelengths. The photon pairs generated collinearly with respect to the pump light via a nonlinear process in a nonlinear optical medium are collected into a single mode fiber and split using a dichroic device. The wavelengths of photons constituting a pair are selected such that, first, their efficient propagation in the same single mode optical fiber, and second, their efficient splitting with high switching ratio, is possible. A detected rate ˜105-106 pairs/s and >98% quantum interference visibility of polarization entanglement is observed. This source, given its performance, robustness and minimum alignment requirements is ideal for quantum communication schemes, in particular for entanglement-based quantum cryptography.

Abstract: A method of despeckling light that includes mixing high-speckle laser light with low-speckle laser light in amounts selected to achieve a desired color point in a digital image. The high speckle laser light may be red laser diodes and the low-speckle laser light may be green stimulated-Raman-scattering light from an optical fiber. The desired color point may be DCI red or Rec. 709 red.

Abstract: The present invention relates to a device for controlling optical frequency (F1, F2) about a central working frequency (F0). This device comprises a vertical cavity (2) formed of two parallel and partially reflecting walls (3a, 3b), and a membrane (6) comprising at least one layer (7a, 7b) structured in the form of a photonic crystal. In this device, the two walls (3a, 3b) are separated by an optical distance substantially proportional to half the wavelength (?0) corresponding to the central working frequency (F0). The membrane (6) is integrated between the walls (3a, 3b) of the cavity (2) and devised in such a way as to exhibit a mode of optical resonance at this central working wavelength (?0). At least one layer of the device is made up of at least one portion of a material exhibiting nonlinear optical properties.

Abstract: A terahertz continuous wave generator includes: an optical intensity modulator configured to modulate an optical signal into DSB optical signals; a local oscillator configured to generate a modulation signal for modulating the optical signal inputted to the optical intensity modulator into DSB optical signals; a notch filter configured to filter an optical signal with a specific frequency; an optical fiber amplifier configured to amplify an output signal of the optical intensity modulator; an optical circulator configured to transmit the optical signal inputted to the optical fiber amplifier to the notch filter and transmit the optical signal reflected from the notch filter to an input of the optical intensity modulator; an optical coupler configured to apply the optical signal to the optical intensity modulator; and an OE converter configured to photomix the DSB signals outputted through the notch filter.

Abstract: Compact laser systems are disclosed which include ultrafast laser sources in combination with nonlinear crystals or waveguides. In some implementations fiber based mid-IR sources producing very short pulses and/or mid-IR sources based on a mode locked fiber lasers are utilized. Some embodiments may include an infrared source with an amplifier system comprising, in combination, a Tm fiber amplifier and an Er fiber amplifier. A difference frequency generator receives outputs from the Er and/or Tm amplifier system, and generates an output comprising a difference frequency. Exemplary applications of the compact, high brightness mid-IR light sources include medical applications, spectroscopy, ranging, sensing and metrology.

Abstract: Various embodiments include modelocked fiber laser resonators that may be coupled with optical amplifiers. An isolator may separate the laser resonator from the amplifier, although certain embodiments exclude such an isolator. A reflective optical element on one end of the resonator having a relatively low reflectivity may be employed to couple light from the laser resonator to the amplifier. Enhanced pulse-width control may be provided with concatenated sections of both polarization-maintaining and non-polarization-maintaining fibers. Apodized fiber Bragg gratings and integrated fiber polarizers may be also be included in the laser cavity to assist in linearly polarizing the output of the cavity. Very short pulses with a large optical bandwidth may be obtained by matching the dispersion value of the fiber Bragg grating to the inverse of the dispersion of the intra-cavity fiber. Frequency comb sources may be constructed from such modelocked fiber oscillators.

Abstract: A wavelength converter includes a supporting substrate and a ferroelectric substrate, the ferroelectric substrate includes at least one waveguide facing the supporting substrate and at least one wavelength-filtering pattern positioned between the waveguide and the supporting substrate, the waveguide includes a plurality of inverted domains and non-inverted domains configured to convert an infrared light into a green light, and the infrared light emitted from the semiconductor laser enters the waveguide of the wavelength converter. For example, the wavelength-filtering pattern includes a Bragg grating.

Abstract: Disclosed is an exemplary wavelength converting illumination probe having an illumination probe that can be selectively connected to a light source configured to generate light at a first wavelength range. The illumination probe including a lumen defining an aperture in a distal end of the illumination probe for emitting light. The wavelength converting illumination probe further including a wavelength converting element disposed within the lumen of the illumination probe. The wavelength converting element operable for receiving light from the light source at the first wavelength range, and converting the light to a second wavelength range.

Abstract: A laser light source includes a semiconductor laser, a wavelength converting element made of a non-linear optical crystal for converting excitation light from the semiconductor laser into wavelength converted light having a wavelength different from the wavelength of the excitation light, a photodiode for measuring a part of the wavelength converted light to be emitted from the wavelength converting element as output light, a photodiode for measuring the excitation light to be emitted from the wavelength converting element, and a control circuit, wherein the control circuit simultaneously performs an output constant control of making the intensity of the wavelength converted light constant, using a current driving circuit, and a temperature control of adjusting the temperature of the wavelength converting element, using a heater.

Abstract: A photoluminescent composition (“phosphor ink”) comprises a suspension of particles of at least one blue light (380 nm to 480 nm) excitable phosphor material in a light transmissive liquid binder in which the weight loading of at least one phosphor material to binder material is in a range 40% to 75%. The binder can be U.V. curable, thermally curable, solvent based or a combination thereof and comprise a polymer resin; a monomer resin, an acrylic, a silicone or a fluorinated polymer. The composition can further comprise particles of a light reflective material suspended in the liquid binder. Photoluminescence wavelength conversion components; solid-state light emitting devices; light emitting signage surfaces and light emitting signage utilizing the composition are disclosed.

Abstract: The present invention relates to a method and to an arrangement for the frequency conversion of coherent optical radiation with adjustable wavelength by way of a two-stage non-linear optical process. In the method and the arrangement, a frequency doubling is carried out in a first non-linear optical crystal (301, 302) and a sum frequency generation or a frequency doubling is carried out in a second non-linear optical crystal (401, 402) which is connected downstream. A positively birefringent crystal, in which the frequency doubling is carried out during a phase matching of type I from the extraordinary wave of the output frequency according to the <eeo> scheme, is used as the first non-linear optical crystal (301, 302). The second non-linear optical crystal (401, 402) is chosen such that phase matching is made possible by rotating the crystal in the same spatial plane in which the first crystal (301, 302) must also be rotated during a phase matching.

Abstract: An optical signal processing device includes a waveform width widening unit configured to widen a waveform width of an optical signal; and an optical limiter circuit, to which the optical signal the waveform width of which is widened is input, configured to suppress an intensity of the optical signal in a region where an input intensity and an output intensity are not proportional.

Abstract: The optical fiber delivery system for delivering optical short pulses includes: a chirped pulse source (10) for emitting an up-chirped optical short pulse having high peak power; optical waveguide unit (20) for delivering the optical short pulse emitted from the chirped pulse source (10); negative group-velocity dispersion generation unit (30) for providing negative group-velocity dispersion to the optical short pulse exited from the optical waveguide unit (20); and an optical fiber (40) for delivering the optical short pulse exited from the negative group-velocity dispersion generation unit (30), along a desired distance, in which the optical short pulse emitted from the chirped pulse source (10) is adapted to be exited, from the optical fiber (40), as a down-chirped optical short pulse that is substantially free of waveform distortion resulting from higher-order dispersion.

Abstract: A periodically poled optical waveguide comprising a nonlinear optical crystalline material is provided having poled optical domains slanted with respect to direction of propagation of light within the waveguide. Light reflected from slanted poled optical domains does not couple efficiently back into the optical waveguide, which facilitates reduction of backreflection towards a semiconductor laser source coupled to the waveguide. Reduction of backreflections facilitates stable operation of the semiconductor laser source. A method of manufacturing of a periodically poled optical waveguide with slanted poled domains is also provided.

Abstract: A signal waveform measuring apparatus 1A is configured from: a signal optical system 11, a reference optical system 16, a time difference setting unit 12 setting a time difference between signal light L1 and reference light L2, a wavelength conversion element 20 including an aggregate of crystals of a dye molecule and generating converted light L5, which has been wavelength-converted to a shorter wavelength than incident light made incident on the crystal aggregate, at an intensity proportional to an r-th power (r>1) of the intensity of the incident light, a photodetector 30 detecting the converted light L5, generated at the element 20 at the intensity that is in accordance with the intensity of the signal light L1, the intensity of the reference light L2, and the time difference between the two, and a signal waveform analyzer 40 performing analysis of the detection result of the converted light L5 and thereby acquiring a time waveform of the signal light L1.

Abstract: A method, a device, and a system for realizing data transmission extension in a passive optical network (PON) are provided. Between a burst-mode clock and data recovery (BCDR) module and an electrical-optical (E/O) amplification module, the device includes a delimiter matching module and a preamble buffering and compensating module. The delimiter matching module is adapted to receive a data frame sent by the BCDR module and determine a location of a delimiter in the data frame. An optical-electrical (O/E) amplification module performs O/E conversion, amplification, and shaping on the data frame. The BCDR module then performs clock and data recovery processing on the data frame.

Abstract: The present invention includes a fundamental laser light source configured to generate fundamental wavelength laser light, a first nonlinear optical crystal configured to generate first alternate wavelength light; a second nonlinear optical crystal configured to generate second alternate wavelength light; a dual wavelength Brewster angle waveplate configured to rotate a polarization of the first alternate wavelength light relative to the second alternate wavelength light such that the first and second alternate wavelength light have the same polarization; a set of Brewster angle wavefront processing optics configured to condition the first and second alternate wavelengths of light; a harmonic separator configured to separate the first alternate wavelength light from the second alternate wavelength light; and a Brewster angle output window configured to transmit the first or second alternate wavelengths of light from the interior of a laser frequency conversion system to the exterior of the laser frequency con

Abstract: The invention relates to an optical bank (1) comprising a carrier (10) for receiving optical components (60, 70) and a crystal (30) that is mechanically connected to the carrier, for changing the frequency of the light irradiated into the crystal (30) from a light source (50). Two rails (12) are arranged essentially in parallel on the carrier (10). The crystal (30) and the carrier (10) are mechanically connected by a surface of the rails (12), facing away from the carrier (10). A heat conducting element (20) is arranged on the crystal, said heat conducting element being applied to the surfaces of the rails (12), that face away from the carrier (10).

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: A non-degenerate polarization-entangled photon pair generation device (1) that efficiently and easily generates non-degenerate polarization-entangled photon pairs includes: a quantum-entangled photon pair generator (2) including a single crystal in which periodically poled structures (3a, 3b) having different periods are formed; and a light radiating unit (4) for entering light into the quantum-entangled photon pair generator (2) such that the light passes through the periodically poled structure (3a) and then through the periodically poled structure (3b).

Abstract: A laser ray wavelength modification apparatus that includes a semiconductor laser element, a fundamental wave light reflecting element, a wavelength modification element, a selective reflection member and a dichroic mirror. The selective reflection member permits fundamental wave light among light rays emitted from the wavelength modification element to pass through to the fundamental wave light reflecting element while reflecting the wavelength modification light. The dichroic mirror is arranged between the semiconductor laser element and the wavelength modification element. The dichroic mirror transmits the fundamental wave light and removes by reflection out the wavelength modification light.

Abstract: A light emitting apparatus has a radiation source for emitting short wavelength radiation. A down conversion material receives and down converts at least some of the short wavelength radiation emitted by the radiation source and back transfers a portion of the received and down converted radiation. An optic device adjacent the down conversion material at least partially surrounds the radiation source. The optic device is configured to extract at least some of the back transferred radiation. A sealant substantially seals a space between the radiation source and the optic device.

Abstract: Provided is an optical comb generator including a light source, a first waveguide region, a modulation region, and a second waveguide region. The light source is configured to output single-mode light. The first waveguide region divides an output of the light source into first light and second light. The modulation region includes a first modulator and a second modulator modulating the first light and the second light respectively. The second waveguide region combines outputs of the first modulator and the second modulator to output an optical comb. Here, the first modulator and the second modulator respectively include a first quantum well and a second quantum well having an asymmetric structure with respect to each other. The light source, the first waveguide region, the modulation region, and the second waveguide region are integrated into one substrate.

Abstract: Embodiments described herein include a system for producing ultrashort tunable pulses based on ultra broadband OPA or OPG in nonlinear materials. The system parameters such as the nonlinear material, pump wavelengths, quasi-phase matching periods, and temperatures can be selected to utilize the intrinsic dispersion relations for such material to produce bandwidth limited or nearly bandwidth limited pulse compression. Compact high average power sources of short optical pulses tunable in the wavelength range of 1800-2100 nm and after frequency doubling in the wavelength range of 900-1050 nm can be used as a pump for the ultra broadband OPA or OPG. In certain embodiments, these short pump pulses are obtained from an Er fiber oscillator at about 1550 nm, amplified in Er fiber, Raman-shifted to 1800-2100 nm, stretched in a fiber stretcher, and amplified in Tm-doped fiber.

Abstract: A wavelength conversion structure includes a light guide formed of a light-transmissive member having a laser light incident port that allows the laser light to be introduced and a phosphor-containing layer that covers at least part of the surface of the light guide. The light guide has a light diffusing structure having asperities formed over the surface of the light guide except a laser light incident surface having the laser light incident port and a light reflecting film formed over the surface of the light guide along the asperities except the laser light incident port and the portion covered with the phosphor-containing layer.

Abstract: A terahertz electromagnetic wave generating element can include a generation layer, and a plurality of pairs of layer structures provided on opposite sides thereof. The layer structures are each provided with a first layer, a second layer on the side of the first layer opposite to the generation layer, and a first grating and a second grating, and having a grating period smaller than the wavelength of the terahertz electromagnetic wave to be used. The first and second gratings are configured so that the refractive index of a medium between the first layer and the second layer continuously varies between a first refractive index and a second refractive index. The thickness of the first and second layers and the grating period, and the grating height are determined so that a terahertz electromagnetic wave having a desired bandwidth with respect to a central wavelength of the terahertz electromagnetic wave generated by the generation layer can be generated.

Abstract: Upon obtaining green light as wavelength converted light by causing infrared light to be incident on a wavelength conversion element, the absorption of the green light occurs due to the generation of ultraviolet light as sum-frequency light of the infrared light and the green light in the wavelength conversion element and the destruction of a crystal composing the wavelength conversion element occurs due to heat generated at this time. In a laser wavelength converter of the present invention, a condensed position of the infrared light in the wavelength conversion element is deviated from a position assumed to be optimal when the influence of the generated heat is ignored. Consequently, crystal destruction is suppressed, a high-efficiency wavelength conversion is enabled and high-output wavelength converted light exceeding several watts, which was difficult to attain in conventional wavelength conversion elements, is attained.

Abstract: A wavelength conversion device includes an excitation light source (11) that generates excitation light, a laser medium (12) that generates fundamental light by means of the excitation light, two resonator mirrors (13) that are disposed with the laser medium (12) being interposed therebetween and resonate the fundamental light, a wavelength conversion element (14) that is disposed between the two resonator mirrors (13) and wavelength-converts the fundamental light to harmonic light, and a drive unit (15) that generates a pulse modulation signal to pulse-drive the excitation light source (11). The laser medium (12) is formed of a material having a thermo-optical effect and a positive thermo-optical constant. The pulse modulation signal generated by the drive unit (15) has an initial interval (P1) including a rising edge of a pulse and a remaining interval (P2) subsequent to the initial interval.

Abstract: This invention relates to methods and apparatus for generating an optical frequency comb. In embodiments a passive mode locked optical waveguide comb uses electrical or optical tuning for the mode spacing frequency (df) and the carrier envelope offset frequency (fceo). We describe a passive mode locked optical comb frequency source comprising: an optical cavity having an optical driver and an optical output to provide an optical comb; an absorbing element coupled to said optical cavity for producing said optical comb; and an optically or electrically controllable element in said optical cavity; and wherein said optically or electrically controllable element has an optically or electrically controllable refractive index such that said refractive index is variable to vary one or both of a mode spacing and a carrier envelope offset frequency of said optical comb.

Abstract: A wavelength conversion device enabling the stable output of high-power harmonic light is disclosed. The wavelength conversion device includes MgO:LiNbO3 (PPMgLN) having a periodic polarization reversed structure, and the +Z and ?Z surfaces of the PPMgLN are covered with thin chrome (Cr) film. In the PPMgLN, the incident surface and output surface are disposed on the ?X side and +X side, respectively, in the longitudinal direction. Because of this structure, even when a high-power laser fundamental wave is incident, the PPMgLN can avoid destruction and damage due to the electric field, thereby enabling the stable output of high-power harmonic.

Abstract: A nonlinear optical crystal can be mounted to a mounting block configured to receive the crystal. The crystal can be mounted to the mounting block with a face of the crystal abutting a surface of the mounting block. An adhesive secures the crystal to the mounting block by adhering to the bottom and/or sidewall of the channel and to at least corresponding a portion of the bottom and/or side face of the crystal proximate an edge of the crystal.

Abstract: An optical frequency converter includes a waveguide including a core made of a nonlinear optical medium having a refractive index n1,light in a wavelength region of light, and cladding disposed so as to cover the core and made of a material whose refractive index n2,light in the wavelength region of light is lower than the refractive index n1,light, and a coupling section made of a material whose refractive index n3,THz in a wavelength region of a terahertz wave is higher than the refractive index n1,light and disposed in contact with the cladding. The coupling section is configured to couple the waveguide with a space in the wavelength region of the terahertz wave. The coupling section covers the cladding.

Abstract: Crystals of the yttrium/aluminium/borate family are used for producing blue or UV light. To produce blue or UV light with the described crystal family a crystal of the family AxM1-xX3(BO3)4, wherein both A and also M stand for an element from the group Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, A?M and X=Al, Ga, Sc and 0?x?1, is used as a non-linear optical element to produce light of a wavelength of less than 0.450 ?m.