An ultrashort light pulse oscillated from an ultrashort pulse oscillator enters a waveguide (2) via a polarization control element (3). After conversion into a supercontinuum by a nonlinear optical effect, it is compressed by a prism pair compressor (71) as pulse compressor (7), and then emitted. The waveguide (2), which is a nonlinear fiber with normal dispersion in the wavelength range from 850 to 1550, generates the supercontinuum having a spectrum continuous in a wavelength band width of at least 200 nm included in the wavelength range from 850 to 1550 nm. The supercontinuum, which has a peak power within 1 to 100 kW, can be used as excitation light in a multiphoton excitation fluorescence microscope for fluorescence observation of biological samples.

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.

An optical fiber, an apparatus for receiving input radiation and broadening a frequency range, a radiation source, a metrology arrangement and a lithographic apparatus are provided. The optical fiber comprises a hollow core, a cladding portion and a support portion. The cladding portion surrounds the hollow core and comprises a plurality of anti-resonance elements for guiding radiation through the hollow core. The support portion surrounds and supports the cladding portion and comprises an inner support portion, an outer support portion and a deformable connecting portion that connects the inner support portion to the outer support portion.

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 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 method of making a microstructured optical fiber including loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T.sub.anneal; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

An ultrashort light pulse oscillated from an ultrashort pulse oscillator enters a waveguide 2 via a polarization control element 3. After conversion into a supercontinuum by a nonlinear optical effect, it is compressed by a prism pair compressor 71 as pulse compressor 7, and then emitted. The waveguide 2, which is a nonlinear fiber with normal dispersion in the wavelength range from 850 to 1550, generates the supercontinuum having a spectrum continuous in a wavelength band width of at least 200 nm included in the wavelength range from 850 to 1550 nm. The supercontinuum, which has a peak power within 1 to 100 kW, can be used as excitation light in a multiphoton excitation fluorescence microscope for fluorescence observation of biological samples.

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 system and process scans a target area at a distance of 3-30 m for one or more materials. Scanning is performed by a coherent transmit beam aimed with the help of a thermal camera. The active source of the beam is a supercontinuum (SC) laser. The transmitted source beam is modulated by a high-speed Fourier-transform spectrometer prior to interaction with the target. Target reflected source beam is detected by an infrared detector, along with a reference portion of the transmitted source beam, as a series of interferograms; passed through a digitizer for digitizing the interferograms; and processed to producing spectrograms, wherein the spectrograms are indicative of one or more materials on the target.

A system includes a light transmitter configured to emit a first light beam. The first light beam includes a primary portion and an amplified spontaneous emission (ASE) portion. The system also includes a host material configured to receive the first light beam and emit a second light. The host material is configured to generate the second light by depopulation of chromophores of one or more dopants in the host material caused by energy of the primary portion of the first light beam. The second light is continuous wave and speckle free.