Abstract: A laser system according to one aspect of the present disclosure includes a wavelength-variable first solid-state laser device configured to output a first pulse laser beam; a wavelength conversion system including a first nonlinear crystal configured to wavelength-convert the first pulse laser beam and a first rotation stage configured to change a first incident angle of the first pulse laser beam on the first nonlinear crystal; an excimer amplifier configured to amplify a pulse laser beam wavelength-converted by the wavelength conversion system; and a control unit configured to receive, from an external device, data of a target center wavelength of an excimer laser beam output from the excimer amplifier, control a wavelength of the first pulse laser beam in accordance with the instructed target center wavelength, and control the first incident angle on the first nonlinear crystal in accordance with an average value of the target center wavelength.

Abstract: An optical amplifier of the present disclosure includes a Raman amplification unit and a parametric amplification unit that is configured of a second-order nonlinear element including a PPLN waveguide. In the optical amplifier, second harmonic lights are generated from a fundamental wave light having a wavelength that is slightly detuned to a shorter wavelength side with respect to a phase matching wavelength of the second-order nonlinear element, and is utilized as excitation light for the parametric amplification unit. By utilizing the excitation light based on the fundamental wave light of the wavelength detuned from the phase matching wavelength, a phase matching curve can be obtained in a wide band in a difference frequency generation (DFG) process of the second-order nonlinear element. The reduction in conversion efficiency of the wavelength near the excitation light in the parametric amplification unit is compensated by the Raman amplification unit.

Abstract: In a wavelength conversion apparatus, reflection suppressors are provided on surfaces of optical elements indicating lenses, dichroic mirrors, and sealing windows excluding a wavelength conversion element in the apparatus between optical fibers F1 and F2 on the input side and optical fibers F3 and F4 on the output side, and on end surfaces of the optical fibers F3 and F4 on the output side. With this, even when light having a wavelength of a sum frequency component of signal light and excitation light is generated at the operation time of wavelength conversion of the wavelength conversion element, because the reflection suppressors suppress the reflection of unwanted light of the wavelength band, the unwanted light is unlikely to return to the wavelength conversion element and it is also possible to suppress a situation in which the unwanted light is mixed into the optical fibers F3 and F4.

Abstract: Embodiments herein describe peak detection techniques for selecting an absorption line to lock a spectroscopy laser in a frequency reference (e.g., an atomic clock). In one embodiment, an atomic reference is used which has many absorption lines within a relatively small frequency range (e.g., within a gain profile of the spectroscopy laser). The peak detection techniques can evaluate which of these lines a laser can be locked to. For example, the peak detection algorithm can define a preferred absorption line. But if for some reason the spectroscopy laser cannot be locked to the preferred absorption line, the peak detection technique has at least one backup absorption line. By having a set of candidate absorption lines, the peak detection algorithm can identify a suitable absorption line for lasers with different gain regions, or as gain regions change.

Abstract: A laser diagnostic device may include a beamsplitter to split one or more input pulses into one or more fundamental pulses and one or more perturbing pulses, one or more beam-combining optics to combine the fundamental and perturbing pulses at a detection plane, a detector including a solid-state material at the detection plane, and a controller. The controller may receive a detector signal from the detector is indicative of nonlinear absorption in the solid-state medium of the fundamental pulses that is perturbed by the perturbing pulses. The controller may further extract a temporal electric field waveform of the one or more input pulses from the detector signal and provide as an output at least one of the temporal electric field waveform, a spectrum, or a spectral phase of the one or more input pulses.

Abstract: The invention relates to the technical field of radar detection, in particular to a device for real-time detection of spectrum from airborne hyperspectral imaging LiDAR and method thereof. The device comprises a laser and a reference module; the reference module comprises a first reflecting mirror and a second reflecting mirror with a given transmittance; the first reflecting mirror and the second reflecting mirror are arranged with a focusing mirror and an optical fiber in sequence therebetween. The laser emits a laser light to the first reflecting mirror with a given transmittance, and the beam of the laser light transmitted through the first reflecting mirror after passing the focusing mirror is used as the reference beam after passing the optical fiber. The invention enables detection of the spectral line of each pulse and improves the precision of reflection spectrum of the ground object measured by the system.

Abstract: A nonlinear crystal including stacked strontium tetraborate SrB4O7 (SBO) crystal plates that are cooperatively configured to create a periodic structure for quasi-phase-matching (QPM) is used in the final frequency doubling stage of a laser assembly to generate laser output light having a wavelength in the range of about 180 nm to 200 nm. One or more fundamental laser beams are frequency doubled, down-converted and/or summed using one or more frequency conversion stages to generate an intermediate frequency light with a corresponding wavelength in the range of about 360 nm to 400 nm, and then the final frequency converting stage utilizes the nonlinear crystal to double the frequency of the intermediate frequency light to generate the desired laser output light at high power. Methods, inspection systems, lithography systems and cutting systems incorporating the laser assembly are also described.

Abstract: In a laser system according to an aspect of the present disclosure, the following components are disposed: a first container that accommodates a first heater and a first crystal holder holding a first nonlinear crystal and includes a first light incident window via which laser light is incident and a first light exit window via which the laser light exits; a second container that accommodates a second heater and a second crystal holder holding a second nonlinear crystal and includes a second light incident window via which the laser light is incident and a second light exit window via which the laser light exits; and a stage that holds the first and second containers. A controller controls the stage to move the first nonlinear crystal away from the optical path of the laser light and inserts the second nonlinear crystal into the optical path of the laser light.

Abstract: A nonlinear crystal grating assembly including two integral nonlinear crystal grating structures having inverted crystal axes and having parallel spaced-apart mesas with predetermined mesa widths arranged such that, when assembled in an interdigitated configuration, the mesas of the two grating structures form an alternating grating pattern that is aligned with a propagation direction of input light, thereby creating a periodic structure for quasi-phase-matching (QPM). The nonlinear crystal grating structures are formed using strontium tetraborate, lithium triborate or another nonlinear crystal material. The nonlinear crystal grating assembly is utilized in a laser assembly in which fundamental wavelengths are doubled and/or summed using intermediate frequency conversion stages, and then a final frequency converting stage utilizes the nonlinear crystal grating assembly to double or sum one or more intermediate light beam frequencies to generate laser output light at high power and photon energy levels.

Abstract: The disclosed technology generally relates to characterization of semiconductor structures, and more particularly to optical characterization of high-k dielectric materials. A method includes providing a semiconductor structure comprising a semiconductor and a high-k dielectric layer formed over the semiconductor, wherein the dielectric layer has electron traps formed therein. The method additionally includes at least partially transmitting an incident light having an incident energy through the high-k dielectric layer and at least partially absorbing the incident light in the semiconductor. The method additionally includes measuring a nonlinear optical spectrum resulting from the light having the energy different from the incident energy, the nonlinear optical spectrum having a first region and a second region, wherein the first region changes at a different rate in intensity compared to the second region.

Abstract: A wavelength conversion device includes a second-order nonlinear optical medium with a polarization inversion structure, wherein the wavelength conversion device performs wavelength conversion between three wavelengths according to a relationship of 1/?1=1/?2+1/?3, a polarization inversion period ? of the polarization inversion structure is divided into 2a regions, and when the 2a regions divided from the polarization inversion period ? each has a width ratio of an inverted region and a non-inverted region of r to 1?r (where 0?r?1), a ratio value r is set such that, when one period in phase of a sine function from 0 to 2? is divided into 2a regions, a value of the sine function in a center of each divided region is (1?2r)±0.1.

Abstract: The invention is related to a parametric light generation method and its application and belongs to the technical field of laser and nonlinear optics. The generation method comprises steps as follows: a nonlinear optical material that meets the sum-frequency phase-matched conditions, namely it shall satisfy the energy conservation condition ?p+?i=?s and the momentum conservation condition np?p+ni?i=ns?s simultaneously, is provided; laser light with a wavelength of ?p is injected into the said nonlinear optical material as pump light; then, the material will output signal light with a wavelength of ?S, namely the tunable sum-frequency parametric light. With sum-frequency as the basic principle, the invention can realize frequency up-conversion and obtain visible and UV light sources through simple infrared light sources easily.

Abstract: A coherent anti-stokes Raman scattering apparatus for imaging a sample includes an optical output; an optical source arranged to generate a first optical signal at a first wavelength; and a nonlinear element arranged to receive the first optical signal, where the nonlinear element is arranged to cause the first optical signal to undergo four-wave mixing on transmission through the nonlinear element such that a second optical signal at a second wavelength and a third optical signal at a third wavelength are generated, wherein an optical signal pair including two of the first, second and third optical signals is provided to the optical output for imaging the sample.

Abstract: A frequency conversion laser system is configured with a single mode (SM) laser source outputting a pulsed pump beam at a fundamental frequency and a nonlinear optical system operating to convert the fundamental frequency sequentially to a second harmonic (SH) and then third harmonic (TH). The nonlinear optical system includes an elongated SHG crystal traversed by the SM pulsed pump beam which generates the SH beam. The SHG crystal has an output surface inclined relative to a longitudinal axis of the SHG crystal at a first wedge angle different from a right angle. The nonlinear optical system further has an elongated THG crystal with an input surface which is impinged upon by a remainder of the pump and SHG beams which propagate through the THG crystal at a walk-off angle therebetween to generate a third harmonic (TH) beam, the input surface of the THG crystal being inclined to a longitudinal axis of the THG crystal at a second wedge angle.

Abstract: An optical waveguide structure comprises a nonlinear optical waveguide comprising a nonlinear optical material having a second order nonlinear coefficient that changes with a direction of light propagation. A first portion of the nonlinear optical waveguide in which a light propagating through the first portion is affected by a positive value of a second order nonlinear coefficient. A second portion of the nonlinear optical waveguide in which the light propagating through the first portion is affected by a negative value of a second order nonlinear coefficient, wherein a set of dimensions in the nonlinear optical waveguide in the first portion and the second portion is selected to cause the light to have a phase walk-off that is an odd multiple of 180 degrees.

Abstract: Methods and systems are provided for separating polarized UV light. In one example, a method may include passing polarized source light through a first prism, the polarized source light including desired light and undesired light, separating the desired light from the fundamental light, and passing the separated desired light through a second prism. The separated desired light which is passed through the second prism may then be further passed through a spatial filter.

Abstract: Exemplary systems for detecting water include: a light source positioned to transmit thermal radiation through a sample; a lens assembly positioned to: receive the thermal radiation transmitted through the sample; and focus the transmitted thermal radiation onto a filter positioned between the lens assembly and a detector; and a cooling subsystem for cooling the filter and the detector to a temperature below that of the sample. Methods for detecting presence of water in a sample are also disclosed.

Abstract: A light source device of the present disclosure includes a light source, a wavelength conversion unit having a fluorescent material excited by a light output from the light source and generating fluorescence and a fluorescent material supporting substrate supporting the fluorescent material, and a housing part with the light source fixed thereto supporting the wavelength conversion unit, wherein the wavelength conversion unit is shiftably supported relative to the housing part.

Abstract: In accordance with various embodiments, a multi-wavelength beam output is formed by stabilizing beams each to a unique wavelength with a stabilizing dispersive element, which reflects a portion of the beam back to its emitter to stabilize the beam and transmits the stabilized beam. The stabilized beams are then transmitted to a combining dispersive element that combines the stabilized beams into the multi-wavelength beam output.

Abstract: An object is to provide, for example, an optical wavelength conversion device capable of highly efficient wavelength conversion on the surface of, or inside, the main body of any of various shapes, such as a bulky shape and a fiber shape. The optical wavelength conversion device includes a main body configured to allow light to propagate therein, and a plurality of crystal regions arranged inside the main body along a propagation direction of the light. The plurality of crystal regions each have a spontaneous polarization oriented along the propagation direction (i.e., spontaneous polarization having a polarization orientation coinciding with the propagation direction).

Abstract: A wavelength-tunable light source includes a wavelength-tunable laser including a first region and a second region each of which includes at least one of heaters, a frequency locker configured to receive output light of the wavelength-tunable laser and output two electric control signals whose phases are mutually different by 90° and having frequency period with respect to frequency of the output light, a thermal electric cooler on which the wavelength-tunable laser and the frequency locker are mounted, and a controller configured to control temperature of the heaters, and the thermal electric cooler on the basis of any one of the two electric control signals.

Abstract: A terahertz-wave generation method of generating a terahertz wave in a direction satisfying a non-collinear phase-matching condition by making pump light incident on a nonlinear optical crystal capable of generating a terahertz wave by optical parametric effect, makes the pump light incident on the nonlinear optical crystal so that a peak excited power density is equal to or greater than a predetermined terahertz-wave lasing threshold and equal to or less than a predetermined laser damage threshold, and an average excited power density, is equal to or less than a predetermined photorefractive effect occurrence threshold, the pump light having a pulse width of 10 ps or more, the pulse width of 1 ns or less, and a repetition frequency of 1 kHz or more.

Abstract: Provided herein is a wavelength converter capable of producing shorter wavelengths by wavelength conversion than in related art. A wavelength converter of the present disclosure includes: a first layer formed of a single crystal represented by general formula RAMO4; and a second layer formed of a single crystal represented by the general formula RAMO4 and having a direction of polarization reversed 180° from a direction of polarization of the first layer, wherein, in the general formula, R represents one or more trivalent elements selected from the group consisting of Sc, In, Y, and a lanthanoid element, A represents one or more trivalent elements selected from the group consisting of Fe(III), Ga, and Al, and M represents one or more divalent elements selected from the group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd.

Abstract: The present invention relates to a novel stand-off distance chemical detector system such as can be used, for example, for standoff detection of explosives. Instead of a conventional lasing medium, a Pr:YAG or Pr:BYF based UV laser is used which can be advantageously implemented in Raman spectroscopy.

Abstract: The present invention concerns a multiple soliton comb generation method comprising the steps of: providing a single optical resonator configured to support a plurality of distinct spatial modes in which light can propagate; providing an optical pump laser source; simultaneously optically pumping a plurality of distinct spatial modes of the single optical resonator to simultaneously generate independent soliton states in the distinct spatial modes and generate a plurality of frequency combs.

Abstract: A resonant-structured optical transistor includes a nonlinear medium which generates a second harmonic wave through second-order nonlinear interaction with an incident pump wave, and generates an amplified signal wave and a converted wave having a difference frequency through second-order nonlinear interaction between the incident signal wave and the second harmonic wave, a first mirror which transmits, to the nonlinear medium, the pump wave or the signal wave, and reflects the second harmonic wave on one surface of the nonlinear medium, and a second mirror which transmits the pump wave, the signal wave, or the converted wave, and reflects the second harmonic wave on another surface of the nonlinear medium. The pump wave is incident to the nonlinear medium through the first mirror in a first operation mode, and the pump wave and the signal wave are incident to the nonlinear medium through the first mirror in a second operation mode.

Abstract: The current disclosure is directed to an apparatus and method of a Laser Designator/Rangefinder (LDR) having two wavelengths of 1064 nm and 1572 nm. The 1064 nm wavelength laser is generated by a pump diode by exciting Nd:YAG medium (source). The 1572 nm wavelength laser is produced using an OPO-OPA converted which is located in a by-pass path. Because the 1572 nm wavelength uses near diffraction limited signal, it provides long range identification and tracking capability needed for advanced tactical platforms, while using the smallest transmit aperture, in a low Size, Weight and Power Consumption (SWaP) package.

Abstract: A system for optical comb carrier envelope offset frequency control includes a mode-locked oscillator. The mode-locked oscillator produces an output beam using an input beam and one or more control signals. The output beam includes a controlled carrier envelope offset frequency. A beat note generator produces a beat note signal using a portion of the output beam. A control signal generator produces the one or more control signals to set the beat note signal by modulating the intensity of the input beam within the mode locked oscillator. Modulating the intensity comprises using a Mach-Zehnder intensity modulator or using an intensity modulated external laser to affect a gain medium within the mode-locked laser.

Abstract: A method of manufacturing an electronic device formed in a cavity may include, on a first substrate having a bottom surface and a top surface, forming a first side wall of a certain height along a periphery on the bottom surface to surround an electronic circuit disposed on the bottom surface; forming a via communicating between the bottom surface and the top surface, forming of the via including stacking a first stop layer and a second stop layer sequentially on a portion of the bottom surface of the first substrate corresponding to the via and etching the first substrate to form a through-hole corresponding to the via, a rate of etching the first substrate being greater than that of the first stop layer and a rate of etching the first stop layer being greater than that of the second stop layer; forming a second side wall of a certain height along a periphery on a top surface of the second substrate; and aligning and bonding the first side wall and the second side wall.

Abstract: A waveguide having a light-shielding film formed on a cut surface of an edge side of the planar waveguide, the light-shielding film having a thickness of 2 to 10 ?m and an optical density (OD) of 0.7 to 1.0 based on a light-shielding film thickness of 1.0 ?m, and a method for manufacturing the same.

Abstract: A converter includes a combiner configured to polarization-combine a first pump light and a second pump light, a nonlinear medium configured to wavelength-convert first signal light into second signal light to output the second signal light after wavelength conversion from a second port, and to wavelength-convert the second signal light into first signal light to output the first signal light after wavelength conversion from the first port, a first circulator configured to input the first signal light from the first port into the nonlinear medium, and output the first signal light after wavelength conversion in the nonlinear medium from the first port, and a second circulator configured to input the second signal light from the second port into the nonlinear medium, and output the second signal light after wavelength conversion in the nonlinear medium from the second port.

Abstract: A frequency-doubled laser, including: a first reflecting mirror, a second reflecting mirror, a gain medium, a telescope module, a polarizing element, and a nonlinear crystal; the first reflecting mirror and the second reflecting mirror are spaced apart to form a resonator of the frequency-doubled laser; the polarizing element, the gain medium, the telescope module, and the nonlinear crystal are located in the resonator, and the telescope module is located between the gain medium and the nonlinear crystal. The present disclosure further provides a method of generating harmonic laser. The frequency-doubled laser and the method of generating harmonic laser make the position of nonlinear crystal more flexible, and the possibility of damage to the nonlinear crystal is reduced.

Abstract: Various embodiments of the present technology provide a novel architecture for optical frequency conversion in a waveguide which can be applied to any suitable nonlinear waveguide material and any wavelength. In accordance with some embodiments, phase-matched bends can be used to increase the nonlinear interaction length. For example, the device can begin with a straight waveguide section with a width designed for phase-matching. When the straight waveguide section approaches the end of the chip, a bending waveguide section allows the waveguide to meander back in the opposite direction. Various embodiments of the bend can have a wider or narrower width to eliminate phase-matching for second harmonic generation (SHG) and instead provide a 2? phase-shift between the pump and signal light. Therefore, at the end of the bend, the pump and signal light are in-phase and a phase-matched width will continue the SHG process.

Abstract: An optical ring-resonator converts visible wavelength radiation to ultraviolet wavelength radiation by frequency-doubling the visible wavelength radiation in an optically nonlinear crystal. The resonator includes an uncoated birefringent out-coupling prism. The visible wavelength radiation passes through faces of the prism at a Brewster-angle. Ultraviolet wavelength radiation enters the prism, is totally internally reflected, directed out of the prism at a Brewster-angle, and exits the ring-resonator as output radiation.

Abstract: The invention relates to a drive system (1) with electromagnetic energy transfer. The system (1) comprises a track (3) comprising a plurality of stators (4), each stator (4) having at least one winding adapted to generate a magnetic field having a fundamental harmonic (8) and at least one further harmonic (9) when fed with an varying current, and a movable element (2) comprising a primary magnetic element (5) adapted to receive said fundamental harmonic (8) to drive said movable element (2) along said track. The system (1) is characterized in that said movable element (2) further comprises a secondary magnetic element (6a-6c) adapted to receive said at least one further harmonic (9) to generate power onboard of said movable element (2). The invention also relates to a linear fractional slot synchronous machine and a rotational synchronous machine.

Abstract: An apparatus for generating narrow-band single and multi-photon state with long coherence length is disclosed. The apparatus comprises a laser pump (20) producing laser light, a non-linear optical crystal (30) within an optical cavity (40), wherein the optical cavity (40) comprises at least two mirrors (42, 44); and a tuning crystal (50) situated between the non-linear optical crystal (30) and a first one (42) of the at least two mirrors.

Abstract: The present application discloses various embodiments of a high peak power laser system which includes a diode pump source configured to directly pump at least one optical crystal positioned within the laser cavity, the diode pump source emitting at least one pump beam comprised of two or more vertically stacked optical signals having a wavelength from about 400 nm to about 1100 nm., the optical crystal configured to output at least one optical output having a wavelength of about 750 nm to about 1100 nm and having an output power of about 25 kW or more.

Abstract: A compound is generally provided that has the formula: Ln3-xBxM5-yByO12, where Ln comprises Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, or a mixture thereof; x is 0 to about 1.5; M comprises Ga, In, Al, Fe, or a combination thereof; y is 0 to about 2.5; and x+y is greater than 0. A composition is also provided that includes a silicon-containing material (e.g., silicon metal and/or a silicide) and the boron-doped refractory compound having the formula described above, such as about 0.001% to about 85% by volume of the boron-doped refractory compound.

Abstract: A laser light-source apparatus includes: a fiber amplifier and a solid-state amplifier to amplify pulse light output from a seed light source serving as a first light source; a nonlinear optical element to perform wavelength conversion on the pulse light output from the solid-state amplifier; an optical switching element to permit or stop propagation of the pulse light from the fiber amplifier to the solid-state amplifier; a second light source disposed on an upstream side of the solid-state amplifier and is configured to output laser light able to be combined with the pulse light output from the seed light source; and a control unit to control the optical switching element in such a manner that the propagation of light is stopped and to perform control in such a manner that the second light source oscillates, at least in an output period of the pulse light from the seed light source.

Abstract: According to one embodiment, a quantum computation apparatus includes a plurality of quantum nonlinear oscillators, a controller, and a measuring device. Each of the quantum nonlinear oscillators implements superposition of distinguishable quantum states by bifurcating one quantum state via a quantum adiabatic change controlled by a bifurcation parameter. The quantum nonlinear oscillators couple with each other by nondissipative coupling accompanying no loss. The controller individually controls the bifurcation parameters of the quantum nonlinear oscillators. A measuring device measures outputs from the quantum nonlinear oscillators.

Abstract: A method for the inscription of second-order nonlinear optical properties on a support including an amorphous material, the method including: heating the support within a temperature range allowing the movement of charges inside the support; applying a structured electrode to the support, generating an electrical field designed to induce the formation of non-linear optical properties on the surface of the support; and cooling the support.

Abstract: An optical system including a laser system for generating a plurality of coaxial laser beams. The laser beams are combined by the laser system for generating at least two different frequency components. One or more hollow core photonic crystal fibers each filled with a noble gas receive the coaxial laser beams from the laser system and generate an idler emission having an idler frequency component according to four-wave mixing of the at least two different frequency components in the one or more hollow core photonic crystal fibers. A control system is configured to control a gas pressure of the one or more hollow core photonic crystal fibers for controlling the idler frequency component of the idler emission.

Abstract: The present invention belongs to the technical field of lasers, and particularly relates to a periodically poled crystal and an optical parametric amplifier. The present invention provides a periodically poled crystal, including a first nonlinear region, a linear region and a second nonlinear region, wherein the first nonlinear region and the second nonlinear region both have periodically poled structures. The optical parametric amplifier having the periodically poled crystal can separate the idler wave from the signal wave besides achieving the basic function of optical parametric amplification because the by-produced idler wave transmits in a direction different from the directions that the signal wave and the pump wave transmit, and therefore the energy reflow is suppressed when the optical parametric amplifier has reached saturated amplification, and the performance of the optical parametric amplifier is significantly improved.

Abstract: A system includes a laser system having a master oscillator and a planar waveguide (PWG) amplifier having one or more laser diode pump arrays, a pumphead, input optics, and output optics. The system also includes an optical bench and cooling manifold coupled to the pumphead. The optical bench and cooling manifold is configured to provide coolant to the one or more laser diode pump arrays and the pumphead through the optical bench and cooling manifold. The optical bench and cooling manifold is also configured to partially deform during operation of the laser system. A housing of the pumphead is coupled to the input and output optics to maintain optical alignment of the pumphead with the input and output optics.

Abstract: An external resonator type light emitting system includes a light source oscillating a semiconductor laser light by itself and a grating device providing an external resonator with the light source. The system performs oscillation in single mode. The light source includes an active layer oscillating the semiconductor laser light. The grating device includes an optical waveguide having an incident face to which the semiconductor laser is incident and an emitting face of emitting an emitting light of a desired wavelength, a Bragg grating formed in the optical waveguide, and a propagating portion provided between the incident face and the Bragg grating. Formulas (1) to (5) are satisfied.

Abstract: To reduce the optical loss, lower the driving voltage, produce a smaller product, and simplify the production process, an embodiment of the present invention includes a rib waveguide core (101) having a rib region (101r) and two slab regions (101s), where a depletion layer (113) is so formed as to extend from the rib region (101r) to the two slab regions (101s).

Abstract: The present disclosure is directed to laser produced plasma light sources having a target material, such as Xenon, that is coated on the outer surface of a cylindrically-symmetric element (e.g., drum). Embodiments include a pre-pulsing arrangement which can be optimized to reduce irradiation damage to the drum and a pulse trimming unit which can be employed to reduce irradiation damage to the drum. In addition, an embodiment is disclosed wherein the surface of a cylindrically-symmetric element is formed with a plurality of grooves having a groove depth greater than 1 mm and a focusing unit focusing a laser beam and establishing an irradiation site to produce plasma from the target material, with the irradiation site distanced from a groove surface portion to protect the surface portion from irradiation damage.

Abstract: A laser device includes a light source that radiates a laser beam having one or more frequencies, and a nonlinear optical medium on which the laser beam is incident, the non-linear optical medium including at least one dispersive medium that is transparent and arranged along a direction in which the laser beam is radiated. The nonlinear optical medium drives a nonlinear optical process including generation of laser beams having different frequencies. The at least one dispersive medium has an effective thickness that causes a relative phase relationship among all the laser beams relevant to the nonlinear optical process to approximately satisfy a predetermined value.

Abstract: Efficient harmonic light generation can be achieved with ultrathin films by coupling an incident pump wave to an epsilon-near-zero (ENZ) mode of the thin film. As an example, efficient third harmonic generation from an indium tin oxide nanofilm (?/42 thick) on a glass substrate for a pump wavelength of 1.4 ?m was demonstrated. A conversion efficiency of 3.3×10?6 was achieved by exploiting the field enhancement properties of the ENZ mode with an enhancement factor of 200. This nanoscale frequency conversion method is applicable to other plasmonic materials and reststrahlen materials in proximity of the longitudinal optical phonon frequencies.

Abstract: The laser cavity is of the unstable type and is provided with a passive Q-switch, the passive Q-switch comprising a saturable absorber that has an absorption gradient, so that the absorption profile of the saturable absorber is inhomogeneous over the cross section of the beam travelling in the laser cavity.