A third-harmonic conversion arrangement includes a second-harmonic generating crystal and a third-harmonic generating crystal arranged in a polarization loop. The polarization loop, which includes a plurality of mirrors, a polarization-selective reflector, and a polarization rotator, causes plane-polarized fundamental-wavelength radiation being converted to make two passes through the crystals in orthogonally-opposed polarization orientations.

A light processing apparatus includes a first non-linear crystal disk for transmitting a first beam of photons having a first frequency to a second beam of photons having the first frequency and a second frequency oscillating in polarization directions orthogonal to each other, the second frequency being a half of the first frequency. Further included is a waveplate for transmitting the second beam of photons to a third beam of photons by rotating polarization directions of the second beam of photons such that the photons of the first frequency and of the second frequency oscillate in the same polarization directions. A second non-linear crystal disk is configured to transmit the third beam of photons to a fourth beam of photons of the first frequency, the second frequency and a third frequency, the third frequency being approximate a third of the first frequency.

A laser processing apparatus includes: a chuck table that holds a workpiece; a laser beam applying unit that applies a pulsed laser beam having a predetermined line width to the workpiece held by the chuck table; and a processing feeding unit that performs relative processing feeding of the chuck table and the laser beam applying unit. The laser beam applying unit includes: a laser oscillator that oscillates the pulsed laser beam; a focusing device that focuses the pulsed laser beam oscillated by the laser oscillator; and a pulse width adjustment unit that is disposed between the laser oscillator and the focusing device and that generates a time difference in a wavelength region of the pulsed laser beam in the predetermined line width, thereby adjusting the pulse width.

Apparatus and methods for generating controllable, narrow-band radiation at short wavelengths, driven by two colors injected into a structured waveguide. The use of multicolor excitation with the structured waveguide allows the use of very small guided beam diameters, without damaging the waveguide. Reduced guided wave mode area combined with low intensities required to drive wave-mixing frequency conversion allow the use of very compact, high average power, moderate peak intensity femtosecond fiber laser technology to drive useful conversion efficiency of laser light into the deep-UV and vacuum-UV at MHz repetition rates.

Crystalline NH.sub.4Be.sub.2BO.sub.3F.sub.2 or Be.sub.2BO.sub.3F (abbreviated as BBF) has nonlinear optical effect, is not deliquescent in the air, is chemically stable. They can be used in a variety of nonlinear optical fields and will pioneer the nonlinear optical applications in the deep UV band.

An SrB.sub.4O.sub.7 or PbB.sub.4O.sub.7 crystal is configured with a plurality of domains with respective periodically alternating polarity of the crystal axis so that the disclosed crystal is capable of quasi-phasematching (QPM). The disclosed crystal is manufactured by a method including patterning a surface of a crystal block of SrB4O7 or PbB4O7, thereby providing patterned uniformly dimensioned regions with a uniform polarity sign on the surface. The method further includes generating a disturbance on the patterned surface, thereby inverting a sign of crystal polarity of every other region to form the SrB.sub.4O.sub.7 or SrB.sub.4O.sub.7 crystal with a plurality of domains with alternating polarity enabling a QPM mechanism.

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. The output and input surfaces of respective SHG and THG crystals are inclined so as to minimize the walk-off angle between SH and IR pointing vectors in the THG crystal thereby improving the conversion efficiency and TH output beam's ellipticity.

Object: To provide a remote substance identification device that can identify an unidentified substance, such as a harmful substance, from a remote location. Solution: Provided are a remote substance identification device and method, the device comprising a laser device 10 that emits a laser beam to an irradiated space; a wavelength conversion device 20 that converts a wavelength of the laser beam emitted from the laser device into a plurality of different wavelengths and that emits laser beams of the different wavelengths to the irradiated space; a light collecting-detecting device 30, 40, 50 that collects and detects resonance Raman-scattered light generated from an irradiated object due to resonance Raman scattering; and a processor 60 that identifies the irradiated object on the basis of a result detected by the collecting-detecting device 30, 40, 50.

The invention relates to a method of generating frequency-tripled laser radiation (THG). It is the object of the invention to demonstrate an efficient approach to generating frequency-tripled laser radiation. The method according to the invention comprises the following method steps: providing a first laser radiation at a fundamental frequency, coupling the first laser radiation into an optical resonator, which is resonant at the fundamental frequency, generating a second laser radiation by second-harmonic generation of the first laser radiation in a type-I process in a first nonlinear optical crystal (3), which is located in the optical resonator, wherein the second laser radiation has a polarization direction, rotating the polarization direction of the second laser radiation, preferably by an angle of substantially 90, and generating a third laser radiation by generating the sum frequency of the first and second laser radiations in a type-I process in a second nonlinear optical crystal (9), which is likewise located in the optical resonator. The invention also relates to a device for generating frequency-tripled laser radiation.

The invention comprises an infrared source and method of use thereof comprising the steps of: (1) providing a solid state source, comprising an electrically conductive layer of a composition of molybdenum silicide and silicon nitride; (2) providing a heating element embedded in the solid state source; (3) applying an alternating/pulsed current to the heating element to heat the heating element; and (4) heating the electrically conductive layer of molybdenum silicide silicon nitride to at least seven hundred degrees using thermal conduction from the heating element resultant in the electrically conductive layer emitting infrared light in a range of 1.1 to 20 micrometers, where the infrared source operates continuously with heating and cooling of the molybdenum silicide silicon nitride through a differential of at least 200 C. occurring at least five and less than thirty times per second.