Apparatus and method for high-power multi-function millimeter-wavelength (THz-frequency) signal generation using OPO and DFG in a single cavity. In some embodiments, the OPO-DFG cavity includes an optical parametric oscillator (OPO) non-linear material that receives pump light I.sub.P having pump-light frequency and generates two different lower intermediate frequencies of lightan OPO-signal beam I.sub.S and a spatially/temporally overlapping OPO-idler beam I.sub.I. A difference-frequency generator non-linear material then receives the two intermediate-frequency beams I.sub.I and I.sub.S, and the DFG then generates a THz-frequency output signal that has a frequency equal to the difference between the two intermediate frequencies. In some embodiments, a single-piece crystal of non-linear material is used for both OPO and DFG functions. Some embodiments use a bow-tie ring having four mirrors that define the optical path: an I.sub.P-beam-entry mirror, an I.sub.P-light-extraction mirror to remove unconverted I.sub.P-beam, an I.sub.I-beam-extraction mirror, and an I.sub.S-beam-extraction mirror, and a fifth I.sub.THz-beam-extraction mirror.

An RGB light source for a luminaire projector system includes Red, Green and Blue lasers each outputting a randomly polarized (RP) single mode (SM) light with at least a 4 nm spectral linewidth. The Green laser has a MOPFA-structured pump which outputs a pulsed pump beam at a fundamental wavelength in a 1 ?m wavelength range and further includes a SHG. The SHG includes an LBO nonlinear crystal receiving the pulsed pump beam and outputting a train of pulses of BB Green light. The Red laser is configured with a QCW fiber laser pump and a frequency converter with an LBO nonlinear crystal outputting a train of pulses of red light in a 6xx nm wavelength range.

An apparatus for producing a single photon can comprise a modulator that modulates the wavelength of a pump beam based on wavelength of an idler photon of a signal/idler photon pair. A wavelength division multiplexer combines the modulated pump beam and the signal photon in a non-linear element to produce an output photon having a preselected wavelength based on signal photon wavelength and a wavelength of the modulated pump beam.

An optical amplifier arrangement has optical parametric amplifiers and white light generations and harmonic generation, in particular frequency doubling, for generating a wide visible to infrared, in any case near-infrared, spectrum of coherent ultra-short light pulses, in particular with a pump laser. During operation the fundamental is in a wavelength range above 950 nm, and the second signal light and the second idler light of the second optical parametric amplifier together cover a tunability range of wavelengths between 500 nm and 5 m, in particular between 550 nm and 3 m, wherein between wavelengths in the tunability range throughout continuous tuning can be carried out, namely through the degeneration range of the second optical parametric amplifier at the fundamental of the pump laser.

A method and apparatus for analyzing carbon isotope .sup.14C is provided. A carbon isotope analyzer including an isotopic carbon dioxide generator to generate isotopic carbon dioxide from a carbon isotope; a spectrometer including an optical resonator having a pair of mirrors, and a photodetector to determine the intensity of light transmitted from the optical resonator; and a light generator including a light source, a first optical fiber to transmit a light beam from the light source, a second optical fiber for wavelength conversion, the second optical fiber branching from the first optical fiber at a point and combining with the first optical fiber at another point downstream of the branching point, and a non-linear optical crystal to generate light having the absorption wavelength of the isotopic carbon dioxide on the basis of the difference in frequency between light beams transmitted through the optical crystal.

A broad line red light generator is configured with a single mode (SM) pulsed ytterbium (Yb) fiber laser pump source outputting pump light in a fundamental mode (FM) at a pump wavelength which is selected from a 1030-1120 nm wavelength range. The disclosed generator further includes a SM fiber Raman converter spliced to an output of the Yb fiber laser pump source. The Raman converter induces an n order frequency Stokes shift of the pump light to output the pump light at a Raman-shifted wavelength within 1220 and 1300 nm wavelength range with a broad spectral line of at least 10 nm. The disclosed light generator further has a single pass second harmonic generator (SHG) with a lithium triborate (LBO) nonlinear optical crystal having a spectral acceptance linewidth which is sufficient to cover the broad spectral line of the pump light. The SHG generates a SM pulsed broad-line red light with a broad spectral line of at least 4 nm.

Apparatus and method for high-power multi-function millimeter-wavelength (THz-frequency) signal generation using OPO and DFG in a single cavity. In some embodiments, the OPO-DFG cavity includes an optical parametric oscillator (OPO) non-linear material that receives pump light I.sub.P having pump-light frequency and generates two different lower intermediate frequencies of lightan OPO-signal beam I.sub.S and a spatially/temporally overlapping OPO-idler beam I.sub.I. A difference-frequency generator non-linear material then receives the two intermediate-frequency beams I.sub.I and I.sub.S, and the DFG then generates a THz-frequency output signal that has a frequency equal to the difference between the two intermediate frequencies. In some embodiments, a single-piece crystal of non-linear material is used for both OPO and DFG functions. Some embodiments use a bow-tie ring having four mirrors that define the optical path: an I.sub.P-beam-entry mirror, an I.sub.P-light-extraction mirror to remove unconverted I.sub.P-beam, an I.sub.I-beam-extraction mirror, and an I.sub.S-beam-extraction mirror, and a fifth I.sub.THz-beam-extraction mirror.

Methods of generating second harmonic generation (SHG) signals from interfaces formed with, or formed over, a noncentrosymmetric material, e.g., -quartz, are provided. The methods make use of the noncentrosymmetric material as an internal phase reference for the determination of a variety of interfacial electrostatic parameters, including interfacial potential, interfacial charge density, and the sign of the interfacial charge (i.e., net positive or net negative).

A device for quasi-phase-matched frequency doubling of broadband light with uncorrelated spectral phase includes a nonlinear optical material, which in turn includes a domain-reversed grating organized in a series of sections along propagation direction of the broadband light through the nonlinear optical material. Each of the sections is characterized by a respective period of the domain-reversed grating. The period within a first connected subset of the series alternates between two discrete values along the propagation direction. A method for designing the domain-reversed grating includes determining a grating function model describing an ideal nonlinear coefficient of a domain-reversed grating, and discretizing the grating function model to a manufacturable grating function having period restricted to a discrete set of manufacturable periods.

The present application discloses a display device, a backplane and the mold for manufacturing the backplane bracket. The mold is used to imprint molding the sheet raw material; the mold has an elongated imprint mold structure; the two ends of the imprint mold structure have a male and female interworking mold structures; by placing the raw material with different lengths in a plurality of predetermined positions in the imprint mold structure can form a plurality of brackets for combining to a backplane. The present application provides a backplane and the simplified mold structures for manufacturing the backplane bracket, the process to manufacturing the backplane is simplified. By adapting a set of mold can manufacture a plurality of the needed bracket to form a backplane, which greatly reduces the cost of production.