A solid state optical beam steering device and method of operation includes converting a frequency or wavelength of a signal in a non-linear converter associated with one channel just before launch. A second channel has a similar constructions and operation. A processor compares the phase difference between the two channels and uses the difference to horizontally steer a beam without moving mechanical parts. This establishes the solid-state nature of the present disclosure. The non-linear converter may be a quasi-phase matched non-linear converter with alternating crystal domains.

A fluid filled fiber for a quasi-phase matched generator and a laser incorporating such a fluid filled fiber. The laser has a liquid filled fiber with charge transfer molecules dissolved in a solvent. The liquid of the liquid filled fiber comprises or consists essentially of highly polar liquids and/or charge transfer molecules having relatively high molecular dipole values.

A third-harmonic generation method includes frequency-quadrupling a fundamental optical beam via cascaded second-harmonic generation to yield a fourth-harmonic optical beam. The method also includes down-converting the fourth-harmonic optical beam to yield a third-harmonic optical beam. A third harmonic generator includes a monolithic optical element having nonzero quadratic electric susceptibility to (i) frequency-quadruple a fundamental optical beam via cascaded second-harmonic generation, and (ii) down-convert a fourth-harmonic optical beam to yield a third-harmonic optical beam.

Some embodiments are directed to a generating device, including a pulse laser source providing primary photons having at least one wavelength, shaping device(s) acting on the primary photons to provide an input beam, a nonlinear crystal, and controller(s) generating, in the nonlinear crystal, at least one electric field that is synchronous with the input beam and suitable for inducing a phase mismatching in the nonlinear crystal through an electro-optical effect, in order to convert the primary photons of the input beam into secondary photons having wavelengths belonging to a supercontinuum.

A solid state optical beam steering device and method of operation includes converting a frequency or wavelength of a signal in a non-linear converter associated with one channel just before launch. A second channel has a similar constructions and operation. A processor compares the phase difference between the two channels and uses the difference to horizontally steer a beam without moving mechanical parts. This establishes the solid-state nature of the present disclosure. The non-linear converter may be a quasi-phase matched non-linear converter with alternating crystal domains.

A waveguide includes an array of p-i-n junctions formed by ions implanted into the waveguide. The p-i-n junctions concentrate electric fields applied on the waveguide to convert the third order susceptibility .sup.(3) into the second order susceptibility .sup.(2) and induce the DC Kerr effect. The periodic electrical fields concentrated by the p-i-n junctions effectively create a wave vector, which together with the wave vectors of optical beams in the waveguide satisfies phase matching conditions for nonlinear optical effects. The phase matching can significantly enhance the efficiency of the nonlinear optical effects, such as second harmonic generation, sum frequency generation, difference frequency generation, and four-wave mixing. Waveguides with arrays of PIN junctions can also be used in phase modulators, amplitude modulators, and filters.

A heterogeneous waveguide is configured to achieve a nonlinear optical interaction, the waveguide including at least two materials in cross-section. The first material may or may not be poled or patterned and generally has a nonlinear optical property for generating at least one new frequency by mixing two of a plurality of input optical waves, and at least one of the other (second) materials is patterned for defining a waveguide mode in the cross-section, and for achieving phase-matched interactions of the waves along the propagation direction. Alternatively, the second material may be employed in increasing the modal confinement and improving efficiency. The optical modes are distributed between the two or more materials (e.g., in a hybrid mode). Implementations described also include methods of fabricating the heterogeneous waveguide.

An embodiment of the invention relates to an optical device which is capable of realizing a secondary nonlinear optical phenomenon. The optical device is a fiber-type optical device which is comprised of glass containing SiO.sub.2, and includes a core region, a first cladding region, and a second cladding region. At least a part of a glass region configured by the core region and the first cladding region has such a repetition structure that a first section serving as a poled crystal region and a second section serving as an amorphous region are alternately disposed along a longitudinal direction of the optical device.

A method of generating THz radiation includes the steps of generating optical input radiation with an input radiation source device (10), irradiating a first conversion crystal device (30) with the optical input radiation, wherein the first conversion crystal device (30) is arranged in a single pass configuration, and generating the THz radiation having a THz frequency in the first conversion crystal device (30) in response to the optical input radiation by an optical-to-THz-conversion process, wherein a multi-line frequency spectrum is provided by the optical input radiation in the first conversion crystal device (30), and the optical-to-THz-conversion process includes cascaded difference frequency generation using the multi-line frequency spectrum. Furthermore, a THz source apparatus being configured for generating THz radiation and applications thereof are described.

An optical amplifier of the present disclosure includes a Raman amplification unit and a parametric amplification unit that is configured of a second-order nonlinear element including a PPLN waveguide. In the optical amplifier, second harmonic lights are generated from a fundamental wave light having a wavelength that is slightly detuned to a shorter wavelength side with respect to a phase matching wavelength of the second-order nonlinear element, and is utilized as excitation light for the parametric amplification unit. By utilizing the excitation light based on the fundamental wave light of the wavelength detuned from the phase matching wavelength, a phase matching curve can be obtained in a wide band in a difference frequency generation (DFG) process of the second-order nonlinear element. The reduction in conversion efficiency of the wavelength near the excitation light in the parametric amplification unit is compensated by the Raman amplification unit.