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 wavelength conversion system comprising a transport system for a laser beam comprising: a circular polarization laser beam; an articulated arm comprising a mirror at each of its joints, arranged at 45° with respect to said laser beam; each of said mirrors having a phase shift between the reflected components of less than 10°; means for converting said laser beam from circular polarization to linear polarization and providing a linear polarization output laser beam; a non-linear converter for converting the wavelength of said output laser beam to linear polarization.

An apparatus includes a plurality of front-end nonlinear optical crystals and a plurality of back-end nonlinear optical crystals. The front-end nonlinear optical crystals are arranged in a chain and are configured to amplify a received signal. The back-end nonlinear optical crystals are arranged in the chain after the front-end nonlinear optical crystals and are configured to further amplify the received signal and generate an amplified signal. The back-end nonlinear optical crystals are made from a different nonlinear optical crystal than the front-end nonlinear optical crystals.

A hybrid photonic chip comprising a plurality of semiconductor materials arranged to define a chip providing a function, wherein at least a first part of the chip is formed of materials which can be fabricated using a CMOS technique; and at least a second part of the chip which comprises non-linear crystal material and is not subjected to etching process; wherein the second part of the chip in conjunction with the first part is configured to support a propagating low loss single mode.

An apparatus includes a plurality of front-end nonlinear optical crystals and a plurality of back-end nonlinear optical crystals. The front-end nonlinear optical crystals are arranged in a chain and are configured to amplify a received signal. The back-end nonlinear optical crystals are arranged in the chain after the front-end nonlinear optical crystals and are configured to further amplify the received signal and generate an amplified signal. The back-end nonlinear optical crystals are made from a different nonlinear optical crystal than the front-end nonlinear optical crystals.

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 laser light source includes a nonlinear optical medium and a pump laser source configured to generate a pump laser beam to form a signal beam and an idler beam in the nonlinear optical medium by parametric down conversion. The laser light source further includes a seed light source configured to generate a seed signal beam and/or a seed idler beam having a coherence length lesser than a coherence length of the pump laser beam, and a superpositioning device configured to superposition the seed signal beam and/or the seed idler beam with the pump laser beam for joint coupling into the nonlinear optical medium.

Systems and embodiments for an integrated photonics mode splitter and converter are provided herein. In certain embodiments, a system includes a substrate having a first index of refraction. Additionally, the system includes a waveguide layer on the substrate, wherein the waveguide has a second index of refraction different from the first index of refraction. Also, the waveguide layer includes one or more mode splitters that receive at least one of a first photon in a first mode and a second photon in a second mode through an input port and provide one of the first photon through a first output port and the second photon through a second output port. The waveguide layer also includes a mode converter coupled to the second output of a mode splitter, wherein the mode converter receives the second photon through a port and outputs the second photon in the first mode through the port.

The present invention relates to compounds and their nonlinear optical (NLO) crystals of A.sub.3B.sub.11P.sub.2O.sub.23 (A=K, Rb, Cs), their producing method and uses thereof. A.sub.3B.sub.11P.sub.2O.sub.23 (A=K, Rb, Cs) belong to triclinic crystal system, and have a space group of P1, crystal cell parameters of a=6.284(8)-8.784(3) , b=6.338(3)-8.838(3) , c=6.463(3)-8.963(3) , =70-105, =75-106, =76-107 and Z=1 and a unit cell volume of V=257.4(3)-696.0(6) .sup.3. A.sub.3B.sub.11P.sub.2O.sub.23 (A=K, Rb, Cs) compounds were prepared by a high-temperature solid-state reaction method or a hydrothermal method, and A.sub.3B.sub.11P.sub.2O.sub.23 (A=K, Rb, Cs) NLO crystals were prepared by a high-temperature solid-state reaction method, a hydrothermal method or a solution method. These materials can be used to manufacture second harmonic generator, up-down frequency converter, optical parametric oscillator, etc.

A cleansing lighting device includes a laser light source configured to emit light in the visible light spectrum or in the infrared light spectrum. The cleansing lighting device also includes a light frequency up-converter to convert longer wavelength light from the laser light source to shorter wavelength light. The converted light has a dominant wavelength in the portion of the ultraviolet range at or below 380 nm, suitable for the cleansing application. An example cleansing lighting device may also include an optical element, such as a beam shaping lens or a variable optical beam deflector, to distribute the resulting ultraviolet light from the up-converter for the cleansing application. Such a cleansing lighting device may be a standalone device, although the device or individual components for light-based cleansing may be incorporated in a luminaire, for example, together with an artificial light source adapted to general illumination.