A device for generating laser radiation comprises a temperature-controlled optical setup comprising an optically non-linear solid state medium arranged in a resonator and an active region. The outgoing laser radiation is generated from a pump beam introduced into the optically non-linear solid state medium. A first temperature actuator and a second temperature actuator configured to independently adjust temperature values in the active region of the optically non-linear solid state medium. The first temperature actuator is configured regulate a length of the resonator by setting a first temperature value within a first portion of the active region. The second temperature actuator is configured to match phases of wavelengths generated by the outgoing laser radiation and phases of wavelengths of the pump beam radiation by setting a second temperature value within a second portion of the active region.

A terahertz-wave generation method of generating a terahertz wave in a direction satisfying a non-collinear phase-matching condition by making pump light incident on a nonlinear optical crystal capable of generating a terahertz wave by optical parametric effect, makes the pump light incident on the nonlinear optical crystal so that a peak excited power density is equal to or greater than a predetermined terahertz-wave lasing threshold and equal to or less than a predetermined laser damage threshold, and an average excited power density, is equal to or less than a predetermined photorefractive effect occurrence threshold, the pump light having a pulse width of 10 ps or more, the pulse width of 1 ns or less, and a repetition frequency of 1 kHz or more.

An optical device has a first optical layer with a first dispersion response as a first function of wavelength. A second optical layer has a second dispersion response as a function of wavelength that is different than the first function. A separating layer is located between the first and second optical layers and has a lower refractive index than the first layer and the second layer. A thickness of the separating layer is selected such that the first and second dispersion responses combine to create an anomalous dispersion about a target wavelength. The anomalous dispersion results in the optical device emitting a wideband coherent optical output about the target wavelength in response to an optical input at the target wavelength.

Reconfigurable nonlinear frequency conversion waveguide chip based on Mach-Zehnder interferometer coupled micro-ring, the method is based on the integration of waveguide components of phase-adjustable Mach-Zehnder interferometers (MZI) and micro-ring resonators. The chip is illustrated by FIG. 1. The MZI couples light and photons into and output of the micro-ring resonator and controls the micorings' quality factor thus optimize the nonlinear frequency conversion processes inside the ring by the phase-modulator inside the MZI. The micro-ring resonator enables the nonlinear optical generation of new frequency light beams and quantum light sources based on the second-order or third-order nonlinear optical process. Other optical waveguide components in region I and III of FIG. 1 are linear optical circuits for power splitting of pump beams and post-process of generated light beams or photons.

An optic produces a beam of ultraviolet laser radiation from a beam of visible laser radiation and spatially separates the ultraviolet laser beam from the visible laser beam. The optic includes two crystals made of the same optically-nonlinear material that are contact bonded along a planar interface. One crystal has principle crystal axes that are oriented for type-I second-harmonic generation. The ultraviolet laser beam exits the optic through an uncoated surface of the other crystal. The principle crystal axes of the two crystals have different orientations and have reflection symmetry about the planar interface.

Reconfigurable electro-optic frequency shifters are provided. In various embodiments, the optical frequency shifter comprises a continuous optical spectrum medium; a discrete optical spectrum medium optically coupled to the continuous optical spectrum medium; and a tunable element operably coupled to the discrete optical spectrum medium, wherein: the discrete optical spectrum medium has N optical modes (I:{i.sub.1 . . . i.sub.N}), said optical modes being ordered and equidistant in a frequency domain, wherein N is an integer equal to or greater than 3, each of the optical modes (i.sub.n∈I) having a coupling constant κ.sub.e,n with respect to the continuous optical spectrum medium, wherein at least one of the coupling constants κ.sub.e,n is different from the other coupling constants, the optical modes (I) having a coupling constant Ω with respect to one another, wherein the tunable element is configured to control the coupling constant Ω.

A light source unit for an imaging device includes a beam extraction unit configured to receive broadband laser light, to direct at least a part of the broadband laser light having a first wavelength into an amplifier beam path, and to direct a residual laser light into a first illumination beam path. The light source unit further includes an optical amplifier unit arranged in the amplifier beam path and configured to generate amplified laser light having the first wavelength by amplifying the part of the broadband laser light, and a frequency changing unit arranged in the amplifier beam path and configured to generate laser light having a second wavelength from the amplified laser light having the first wavelength.

A electronic method, includes receiving, by a graphene structure, a microwave signal. The microwave signal has a driving voltage level. The electronic method includes generating, by the graphene structure, optical photons based on the microvolts. The electronic method includes outputting, by the graphene structure, the optical photons.

A color conversion panel includes a first color conversion layer, a second color conversion layer, and a light wavelength conversion layer. The first color conversion layer includes a first semiconductor nanocrystal set for providing red light. The second color conversion layer neighbors the first color conversion layer and includes a second semiconductor nanocrystal set for providing first green light. The light wavelength conversion layer neighbors the second light conversion layer, may provide blue light, and includes a third semiconductor nanocrystal set for providing second green light.

An illumination source apparatus (500), suitable for use in a metrology apparatus for the characterization of a structure on a substrate, the illumination source apparatus comprising: a high harmonic generation, HHG, medium (502); a pump radiation source (506) operable to emit a beam of pump radiation (508); and adjustable transformation optics (510) configured to adjustably transform the transverse spatial profile of the beam of pump radiation to produce a transformed beam (518) such that relative to the centre axis of the transformed beam, a central region of the transformed beam has substantially zero intensity and an outer region which is radially outwards from the centre axis of the transformed beam has a non-zero intensity, wherein the transformed beam is arranged to excite the HHG medium so as to generate high harmonic radiation (540), wherein the location of said outer region is dependent on an adjustment N setting of the adjustable transformation optics.