A hollow-core photonic crystal fiber (HC-PCF) assembly for converting input radiation to broadband radiation, the hollow core fiber assembly including: a micro-structured fiber with a hollow core extending along a length of the fiber from an input end configured to receive input radiation to an output end configured to output broadband radiation, wherein the hollow core of the fiber is configured to include a medium; and a density control system configured to control a density profile of the medium along at least a part of the length of the fiber to establish a desired zero dispersion wavelength profile along at least a part of the length of the fiber.

A method of providing optical coherence tomography (OCT) imaging may comprise using an on-chip frequency comb source interfaced with an OCT system by a circulator as an imaging source and reconstructing OCT images from resulting spectral data from target tissue illuminated by the imaging source.

A radiation source includes: a hollow core optical fiber, a working medium; and a pulsed pump radiation source. The hollow core optical fiber has a body and has a hollow core. The working medium is disposed within the hollow core. The pulsed pump radiation source is arranged to produce pulsed pump radiation that is received by, and propagates through, the hollow core from an input end to an output end. One or more parameters of the pulsed pump radiation, the optical fiber and the working medium are configured to allow soliton self-compression of the pulsed pump radiation so as to change a spectrum of the pulsed pump radiation so as to form output radiation. In some embodiments, a length of the optical fiber is such that the output end substantially coincides with a position at which a temporal extent of the pulsed pump radiation is minimal.

A microstructured optical fiber including a core region and a cladding region which surrounds the core region. The cladding region includes a plurality of cladding features within a cladding background material, wherein the cladding region includes an inner cladding region with at least one inner ring of cladding features and an outer cladding region with outer cladding rings of outer cladding features. The inner cladding features have a first characteristic diameter and the outer cladding region includes a plurality of outer cladding features having a characteristic diameter smaller than the first characteristic diameter. The core region has a diameter of at least about 2 m. A cascade optical fiber with at least one fiber as described, as well as a source of optical supercontinuum generation.

A system and method for providing a radiation source. In one arrangement, the radiation source includes an optical fiber that is hollow, and has an axial direction, a gas that fills the hollow of the optical fiber, and a plurality of temperature setting devices disposed at respective positions along the axial direction of the optical fiber, wherein the temperature setting devices are configured to control the temperature of the gas to locally control the density of the gas.

A radiation source for generating broadband radiation, the source including: a pump source having only one single fiber amplifier configured to generate pump radiation including a plurality of radiation pulses having a pulse energy of 2.5 J or less; and a hollow core fiber having a hollow core region and a cladding surrounding the hollow core region, the hollow core region having a pressurized gas therein, and the hollow core fiber being arranged to receive, at an input end, the pump radiation, wherein the hollow core region is dimensioned such that the radiation pulses have a soliton order higher than 16 so as to broaden a spectrum of the pump radiation using modulation instability as the pump radiation propagates along the hollow-core fiber, for providing output broadband radiation from an output end of the hollow core fiber.

A dual-frequency-comb spectrometer and a method for spectroscopic investigation of a sample are described. The spectrometer includes first and second frequency comb devices for emitting laser pulses along first and second light paths, wherein the repetition frequency of the laser pulses emitted by the second device is offset from that of the first device. First and second multi-core waveguides including at least two separate single core waveguides having field-coupling via a coupling gap therebetween are arranged in the first and second light paths. The sample is irradiated by the second frequency comb in the second light path. A detector device is arranged in a third light path where the first and second light paths are combined, for simultaneously sensing the first frequency comb and the second frequency comb after an interaction with the sample. A computing device receives output of the detector device and calculates spectroscopic properties of the sample.

A vehicle light device includes a primary light source configured to emit first light having wavelengths in a first wavelength range, and a conversion element including an input end and an output end, the input end being optically coupled to the primary light source. The conversion element includes a nonlinear optical medium configured to convert at least a portion of the first light to second light having wavelengths shifted from the first light such that the output end outputs collimated light having a broad wavelength range including wavelengths of the first light and wavelengths of the second light. An outer lens is optically coupled to the output end of the wavelength conversion element and configured to transmit the output light as white light for illuminating a path of a vehicle.

A system for modulating a terahertz beam includes a multiferroic nanoparticle heterostructure through which a terahertz beam can be propagated, and means for applying an external direct current (DC) magnetic field to the multiferroic nanoparticle heterostructure and the terahertz beam propagating through it, wherein application of the DC magnetic field modulates one or both of an amplitude and a phase of the terahertz beam.

Aspects of the present disclosure describe improved supercontinuum generation based upon alternating optical dispersion along a waveguide length that advantageously generates much more spectral bandwidth than possible with conventional, prior art techniques without losing coherence as well as supporting a larger range of pulse energies (i.e., for lower than conventionally allowed pulse energies or high pulse energies).