Abstract: A cavity-enhanced frequency mixer includes an input optical fiber, a waveguide, and an output optical fiber. The waveguide has an input end and an output end, the input end is connected to the input optical fiber, and a surface of the input end of the waveguide is coated with a highly reflective coating. The output optical fiber is formed with a fiber Bragg grating structure. The highly reflective coating and the fiber Bragg grating structure form a pair of reflective surfaces for resonant optical parametric oscillation under a low threshold situation, so that one of the beams generated by the input beam is reflected inside the partially reflective surfaces. Operated above a pump power threshold, the cavity-enhanced frequency mixer is tantamount to a compact, low-power budget optical parametric oscillator, while below the pump power threshold, it is a bright, compact, single-mode and narrow linewidth single-photon source.

Abstract: A method is provided for forming a waveguide region within a periodically domain reversed ferroelectric crystal wherein the waveguide region has a refractive index profile that is vertically and horizontally symmetric. The symmetric profile produces effective overlapping between quasi-phasematched waves, a corresponding high rate of energy transfer between the waves and a symmetric cross-section of the radiated wave. The symmetric refractive index profile is produced by a method that combines the use of a diluted proton exchange medium at a high temperature which produces a region of high index relatively deeply beneath the crystal surface, followed by a reversed proton exchange which restores the original crystal index of refraction immediately beneath the crystal surface.

Abstract: A method for forming uniform, sharply defined periodic regions of reversed polarization within a unidirectionally polarized ferroelectric material proceeds as a two-step process. First, alignment keys are formed on upper and lower planar surfaces of a unidirectionally polarized ferroelectric material by producing a spaced pair of alignment key shaped domain reversed regions and etching alignment key shaped notches in the upper and lower surfaces where the domain reversed regions intersect the surface planes. These notches, being vertically aligned between the upper and lower surfaces, are then used to align photomasks over a surface coating of photoresist formed directly on the material surface or on SiO2 layers coating the material surface.

Abstract: A method of patterning and fabricating poled dielectric microstructures in dielectric materials comprising the following steps. A poled dielectric microstructure within a dielectric material is provided. The poled dielectric microstructure is then segmented into a plurality of independent sub-structures. The poled dielectric microstructures are then fabricated within each of the plurality of independent sub-structures. Additional processes and a novel poling setup for improving and implementing this patterning and fabrication method are also disclosed.

Abstract: A method of patterning and fabricating poled dielectric microstructures in dielectric materials comprising the following steps. A poled dielectric microstructure within a dielectric material is provided. The poled dielectric microstructure is then segmented into a plurality of independent sub-structures. The poled dielectric microstructures are then fabricated within each of the plurality of independent sub-structures. Additional processes and a novel poling setup for improving and implementing this patterning and fabrication method are also disclosed.