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 system for generating a mid-infrared optical frequency comb based on a lithium niobate microcavity includes pumping units, a beam combining unit, a nonlinear frequency conversion unit and a filtering unit. The pumping units are divided into two paths and are configured to provide two paths of pumping light. The beam combining unit is configured to perform beam combination on the two paths of pumping light The nonlinear frequency conversion unit is configured to receive the beam-combined pumping light and undergo a nonlinear four-wave mixing process to generate a broadband optical frequency comb at a mid-infrared waveband. The filtering unit is configured to filter the remaining pumping light and output a mid-infrared optical frequency comb.

A photonic device comprises a plurality of resonators and a plurality of optical channels. Each resonator from the plurality of resonators has a set of resonance frequencies independently selected from a set of resonance frequencies of each remaining resonator from the plurality of resonators. Each resonator from the plurality of resonators lacks substantially any linear coupling between each remaining resonator from the plurality of resonators. The plurality of resonators defines a spatial overlap region between at least two resonators from the plurality of resonators such that nonlinear optical processes are substantially optimized during operation. A plurality of optical channels is operatively coupled to the plurality of resonators. The plurality of optical channels is configured to receive light from the plurality resonators and configured to send light into the plurality of resonators.

A photon source includes a bus waveguide, a photon source pump laser coupled to the bus waveguide and a plurality of optical resonators coupled to the bus waveguide. Each optical resonator of the plurality of optical resonators has a respective resonance line width and a respective resonance frequency, wherein a bandwidth of the resonant center frequencies of the plurality of optical resonators is greater than a bandwidth of the photon source pump laser. The bus waveguide produces photons in response to receiving laser pulses from the pump laser.

Supercontinuum (SC) (400 nm to 2500 nm) and a microscope produce enhanced microscopic images on sub-micron to cm scale of linear (.sub.1) and nonlinear (.sub.2, .sub.3, .sub.4 . . . ) processes via resonance including linear absorption, SHG, THG, SRG, SRL, SRS, 2PEF, 3PEF, 4PEF, and inverse Raman in a microscope for 2D and 3D imaging. Images and processes in 2D and 3D arise from electronic and vibrational resonances transitions in biological and medical tissues, cells, condensed matter applications. Resonant Stimulated Raman Scattering (RSRS) is proposed to improve vibrational imaging of biomaterials by using part of SC. Quantum mechanical processes from SC for 2 and 4 photons to improve resolution and imaging using entangled photons are described. The addition of time measuring instrument like a Streak camera and the scattering coefficient .sub.s can be mapped to create images of tissue and biomaterial in 5D: Space (3D), Time, and Wavelength.

The invention relates to an apparatus for generating laser pulses. It is an object of the invention to provide a method for generating synchronized laser pulse trains at variable wavelengths (e.g., for coherent Raman spectroscopy/microscopy), wherein the switching time for switching between different wavelengths should be in the sub-s range. For this purpose the apparatus according to the invention comprises a pump laser (1), which emits pulsed laser radiation at a specified wavelength, an FDML laser (3), which emits continuous wave laser radiation at a cyclically variable wavelength, and a nonlinear conversion medium (4), in which the pulsed laser radiation of the pump laser (1) and the continuous wave laser radiation of the FDML laser (3) are superposed. In the nonlinear conversion medium (4) the pulsed laser radiation of the pump laser (1) and the continuous wave laser radiation of the FDML laser (3) are converted in an optical parametric process into pulsed laser radiation at a signal wavelength and an idler wavelength that differs therefrom. Furthermore the invention relates to a method for generating laser pulses.

A laser apparatus includes: a monitoring device that includes a detector that detects light belonging to a first wavelength range including a peak wavelength of at least one of Stokes light and anti-Stokes light, in preference to light belonging to a second wavelength range; and a multi-mode fiber. The Stokes light and the anti-Stokes light result from, in the multi-mode fiber that guides laser light, four-wave mixing in which a plurality of guide modes are involved.

A photonic device comprises a plurality of resonators and a plurality of optical channels. Each resonator from the plurality of resonators has a set of resonance frequencies independently selected from a set of resonance frequencies of each remaining resonator from the plurality of resonators. Each resonator from the plurality of resonators lacks substantially any linear coupling between each remaining resonator from the plurality of resonators. The plurality of resonators defines a spatial overlap region between at least two resonators from the plurality of resonators such that nonlinear optical processes are substantially optimized during operation. A plurality of optical channels is operatively coupled to the plurality of resonators. The plurality of optical channels is configured to receive light from the plurality resonators and configured to send light into the plurality of resonators.

Radiation source assemblies and methods for generating broadened radiation by spectral broadening. A radiation source assembly includes a pump source configured to emit modulated pump radiation at one or more wavelengths. The assembly further has an optical fiber configured to receive the modulated pump radiation emitted by the pump source, the optical fiber including a hollow core extending along at least part of a length of the fiber. The hollow core is configured to guide the received radiation during propagation through the fiber. The radiation emitted by the pump source includes first radiation at a pump wavelength, and the pump source is configured to modulate the first radiation for stimulating spectral broadening in the optical fiber.

A wavelength converter includes a first phase modulator configured to perform phase modulation on pump light in accordance with a first phase modulation signal, a second phase modulator configured to perform phase modulation on signal light in accordance with a second phase modulation signal, a wavelength converter configured to multiplex the signal light having undergone the phase modulation with the pump light having undergone the phase modulation, the wavelength converter configured to perform wavelength conversion on the signal light in accordance with the pump light, a detector configured to detect a modulation component from the signal light having undergone the phase modulation and the pump light having undergone the phase modulation, and a generator configured to generate the first phase modulation signal and the second phase modulation signal so as to minimize the detected modulation component.