Embodiments of the disclosure provide an apparatus for emitting laser light and a system and method for detecting laser light returned from an object. The system includes a transmitter and a receiver. The transmitter includes one or more laser sources, at least one of the laser sources configured to provide a respective native laser beam having a wavelength above 1,100 nm. The transmitter also includes a wavelength converter configured to receive the native laser beams provided by the laser sources and convert the native laser beams into a converted laser beam having a wavelength below 1,100 nm. The transmitter further includes a scanner configured to emit the converted laser beam to the object in a first direction. The receiver is configured to detect a returned laser beam having a wavelength below 1,100 nm and returned from the object in a second direction.

A laser source includes a first laser device configured to generate a first laser beam having a first wavelength, a second laser device configured to generate a second laser beam having a second wavelength, which is different from the first wavelength, and a non-linear crystal configured to receive simultaneously the first and second laser beams and to generate a third laser beam that has a third wavelength, which is larger than each of the first and second wavelengths. The non-linear crystal has a length and a width, and a variable poling period is distributed across the width so that the third wavelength varies within a given wavelength range based on an incident position of the first and second laser beams along the width of the non-linear crystal.

A non-linear optical crystal, such as a Lithium triborate (LiB.sub.3O.sub.5 or LBO) crystal, includes a first nanostructured optical surface including distributed pillars and gaps having random heights and cross sections to provide anti-reflection control and scatter control of first light incident on the first structured optical surface. The LBO crystal has an anti-reflective random structured optical surface formed by selective substitution of the surface species Boron-pentoxide (B.sub.3O.sub.5.sup.−) by Lithium Fluoride (LiF), resulting in a depletion layer with low reflectivity and low reflective scatter in the visible, ultraviolet (UV), and near infrared (IR) bands. The LBO crystal with the anti-reflective structured optical surface may be a monolithic structure and thus need not include a coating of an anti-reflective (AR) material, although the LBO crystal may include an optical surface coated by an AR material. The pillars and gaps may be randomly distributed or periodically distributed on the optical surface.

This disclosure is directed at a method and device capable of producing polarization entangled photon pairs and accomplishing polarization insensitive wavelength conversion. The device includes a double displacement interferometer, the interferometer of which contains an input beam displacing section including a plurality of orthogonally oriented optical beam displacing elements; a wavelength conversion section including a plurality of orthogonally oriented non-linear optical wavelength converters; an output beam recombination section including a plurality of orthogonally oriented optical beam displacing elements.

A sanitizing device includes a nonlinear optical element, one or more laser diodes, a lens, and a battery pack. The one or more laser diodes are each configured to direct a beam of optical energy to the nonlinear optical element. Each beam of optical energy has a first wavelength and the nonlinear optical element is configured to produce UV-C energy having a second wavelength from the beams of optical energy. The lens is configured to focus the UV-C energy to cover a desired area for sanitizing purposes. The battery pack is configured for powering the one or more laser diodes.

A method of performing HVPE heteroepitaxy comprises exposing a substrate to a carrier gas, a first precursor gas, a Group II/III element, and ternary-forming gasses (V/VI group precursor), to form a heteroepitaxial growth of a binary, ternary, and/or quaternary compound on the substrate; wherein the carrier gas is Hz, wherein the first precursor gas is HCl, the Group II/III element comprises at least one of Zn, Cd, Hg, Al, Ga, and In; and wherein the ternary-forming gasses comprise at least two or more of AsH.sub.3 (arsine), PH.sub.3 (phosphine), H.sub.2Se (hydrogen selenide), HzTe (hydrogen telluride), SbH.sub.3 (hydrogen antimonide, or antimony tri-hydride, or stibine), H.sub.2S (hydrogen sulfide), NH.sub.3 (ammonia), and HF (hydrogen fluoride); flowing the carrier gas over the Group II/III element; exposing the substrate to the ternary-forming gasses in a predetermined ratio of first ternary-forming gas to second ternary-forming gas (1tf:2tf ratio); and changing the 1tf:2tf ratio over time.

This invention proposes to use a specially designed layered nonlinear optic (LNO) for intracavity harmonic generation. The LNO generates the harmonic and guides the generated harmonic beam to a different path from the fundamental beam path with total internal reflection, a phenomenon that all lights are reflected when lights in one (“internal”) optic strike sufficiently obliquely against the interface with a second (“external”) optic, in which the refractive index is lower than that in the internal optic. No coating is necessary for the harmonic inside the fundamental beam laser cavity. The generated harmonic beam does not travel through any surface inside the fundamental beam cavity, either. Hence this invention improves the reliability of intracavity harmonic generation laser especially if the harmonic is in the UV range.

This invention proposes to use a specially designed layered nonlinear optic (LNO) for intracavity harmonic generation. The LNO generates the harmonic and guides the generated harmonic beam to a different path from the fundamental beam path with total internal reflection, a phenomenon that all lights are reflected when lights in one (“internal”) optic strike sufficiently obliquely against the interface with a second (“external”) optic, in which the refractive index is lower than that in the internal optic. No coating is necessary for the harmonic inside the fundamental beam laser cavity. The generated harmonic beam does not travel through any surface inside the fundamental beam cavity, either. Hence this invention improves the reliability of intracavity harmonic generation laser especially if the harmonic is in the UV range.

A quantum source includes: a quantum source generator dividing a pump beam into a plurality of channels and generating a plurality of signals and a plurality of idlers using nonlinear crystals respectively located optical paths of the plurality of channels; and an entangled photon pair combiner outputting an enhanced signal by combining the plurality of signals and outputting an enhanced idler by combining the plurality of idlers.

An inspection device includes: a light source for outputting pulsed excitation light with a time width of 10 picoseconds to 10 nanoseconds; a nonlinear optical crystal for generating a terahertz wave by optical wavelength conversion of the excitation light; and a detector for detecting a reflected wave of the terahertz wave reflected by an inspection target.