The technology disclosed in this patent document can be used to implement an optical device for generating broadband optical pulses, including an optical waveguide having different waveguide structures at different locations along the optical waveguide and with varying dimensions or pressure gradient that change adiabatically along the different locations to enable non-linear four wave mixing over a broad spectral range.

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.

A steerable laser transmitter and situational awareness sensor uses a liquid crystal waveguide (LCWG) to steer a spot-beam onto a conical mirror, which in turn redirects the spot-beam to scan a FOV. The spot-beam passes through one or more annular sections of non-linearly material (NLM) formed along the axis and around the conical mirror. Each NLM section converts the wavelength of the spot-beam to a different wavelength while preserving the steering of the spot-beam. The LCWG may shape or move the spot-beam along the axis of the conic mirror to sequentially, time or time and spatially multiplex the spot-beam between the original and different wavelengths. This provides multispectral capability from a single laser source. The transmitter also supports steering the spot-beam at a wavelength at which the LCWG cannot steer directly.

An extra cavity harmonic generator system may produce a round, non-astigmatic third harmonic output beam from a nominally round, non-astigmatic, diffraction limited input fundamental beam. The system may include a second harmonic generation crystal. An input fundamental beam size is expanded in a non-walkoff direction for the SHG crystal at the SHG crystal input face. A higher harmonic generation crystal has an output face oriented at an oblique angle of incidence in a non-walkoff direction for the HHG crystal such that an output higher harmonic beam size is contracted in this direction. Expansion of the input fundamental beam at the SHG crystal input face exceeds reduction of third harmonic beam at the HHG crystal output face.

A microwave to optical conversion device comprising: a superconducting microwave resonator, and an optical resonator including an electro-optical material, the superconducting microwave resonator and the optical resonator being arranged one with respect to the other so as to be electro-magnetically coupled.

According to some aspects, a transmissive and all-dielectric optical component/limiter with great cutoff efficiency using Vanadium Dioxide (VO.sub.2) as the active component is disclosed. In some embodiments, Vanadium dioxide is used for an optical limiter due to the large contrast in optical constants upon undergoing the semiconductor to metal phase transition. When triggered optically, this transition occurs within 60 fs, making the device suitable for an ultrafast laser environment. In addition, the phase transition threshold is tunable by applying stress or doping; therefore, the device cutoff intensity can be adjusted to fulfill specific requirements.

An optical modulator is disclosed that includes an optical resonator structure. The optical resonator structure includes at least one non-linear portion, the at least one non-linear portion comprising at least one radial junction region. The at least one radial junction region is formed between at least first and second materials, respectively, having different electronic conductivity characteristics. A principal axis of the at least one radial junction region is oriented along a radius of curvature of the at least one non-linear portion. The optical modulator includes an optical waveguide that is coupled to the at least one non-linear portion of the optical resonator structure.

A broadband radiation source device configured for generating a broadband output radiation upon receiving pump radiation, the device including: a hollow-core photonic crystal fiber (HC-PCF) including at least one structurally varied portion having at least one structural parameter of the HC-PCF varied with respect to one or more main portions of the HC-PCF, wherein the at least one structurally varied portion includes at least a structurally varied portion located downstream of a position along the length of the HC-PCF where the pump radiation will be spectrally expanded by a modulation instability dominated nonlinear optical process, and wherein the at least one structurally varied portion is configured and located such that the broadband output radiation includes wavelengths in the ultraviolet region.

A nonlinear crystal comprising a first end face and an opposing second end face is described. The first and second end faces are separated along an optical axis of the nonlinear crystal by a length in the range of 0.25 mm and 2 mm. Although the length of the nonlinear crystal results in a reduction in the nonlinear effects induced on an optical field propagating through the crystal it also provides for reduced deviation experienced by the generated optical field when the nonlinear crystal is rotated. Therefore, when the nonlinear crystals are incorporated within an enhancement cavity their reduced length allows for the deviation of the output field to be minimised by servo control electronics arranged to adjust a single cavity mirror. This significantly reduces the complexity, and thus expensive of the servo control electronics when compared to those employed with the prior art enhancement cavities.

An optical parametric oscillator for producing idler coherent light and signal coherent light from pump coherent light by balanced parametric dispersion includes: substrate cladding; a microring resonator disposed on the substrate cladding and including: a broadly transparent Kerr nonlinear medium including a annulus with a radius R, a height H, and a width W that provides a balanced parametric dispersion; and that: receives pump coherent light from a waveguide; and produces idler coherent light and signal coherent light from the pump coherent light, the idler coherent light and signal coherent light produced according to the balanced parametric dispersion of the microring resonator; and the waveguide disposed on the substrate cladding in optical communication with the microring resonator and comprising a broadly transparent medium such as silicon nitride and that: receives pump coherent light; and communicates the pump coherent light to the microring resonator for production of the idler coherent light and the signal coherent light from the pump coherent light.