Disclosed is an optical component, being configured to function as an optical frequency converter in a broadband radiation source device. The optical component comprises a gas cell, and a hollow-core photonic crystal fiber at least partially enclosed within said gas cell. The local cavity volume of said gas cell, where said hollow-core photonic crystal fiber is enclosed within the gas cell, comprises a maximum value of 36 cm.sup.3 per cm of length of said hollow-core photonic crystal fiber.

An EUV radiation light source generation apparatus includes a pump laser, at least one pulse shaping unit, a wavelength conversion unit, and a high-order harmonics generation unit. The pump laser provides a pulse laser radiation beam. Each pulse shaping unit conducts a spectrum extending operation and a phase compensation operation to the pulse laser radiation beam. The phase compensation operation makes multiple frequency components of the pulse laser radiation beam emitted by the pulse shaping unit to be substantially in phase. The wavelength conversion unit conducts a center wavelength conversion operation to the pulse laser radiation beam. The high-order harmonics generation unit receives the pulse laser radiation beam processed by the pulse shaping unit and the center wavelength conversion operation, and focuses the received pulse laser radiation beam to a high order harmonic generation medium to generate a high order harmonic radiation beam.

Disclosed is an optical component, being configured to function as an optical frequency converter in a broadband radiation source device. The optical component comprises a gas cell, and a hollow-core photonic crystal fiber at least partially enclosed within said gas cell. The local cavity volume of said gas cell, where said hollow-core photonic crystal fiber is enclosed within the gas cell, comprises a maximum value of 36 cm.sup.3 per cm of length of said hollow-core photonic crystal fiber.

An optical source (100) comprising a supercontinuum generation apparatus comprising a pump light source (102), a twisted photonic crystal fibre, PCF, (104) and a wideband quarter-wave retarder (106). The pump light source is arranged to provide circularly polarised pump light. The twisted PCF is arranged to receive the pump light and to convert the pump light into circularly polarised supercontinuum light. The wideband quarter-wave retarder is arranged to convert the circularly polarised supercontinuum light into linearly polarised supercontinuum light. The optical source may additionally comprise a wavelength tunable bandpass optical filter arranged to transmit the linearly polarised supercontinuum light at wavelengths within a selected range.

A mid-infrared broadband laser including: a femtosecond laser configured to generate a near-infrared light; nonlinear waveguide configured to broaden and/or shift a spectrum of the light from the femtosecond laser; and a nonlinear medium configured to generate a broadband light by mixing spectral components of the output from the non-linear waveguide. Optionally, at least one dispersion compensation element may be placed between the femtosecond laser and the nonlinear waveguide and/or between the nonlinear waveguide and the nonlinear medium.

In this patent, we teach methods to generate coherent X-ray and UUV rays beams for X ray and UUV microscopes using intense femtosecond pulses resulting the Ultra-Supercontinuum (USC) and Higher Harmonic Generation (HHG) from χ3 and χ.sup.5 media produce from electronic and molecular Kerr effect. The response of n.sub.2 (χ3) and n.sub.4 (χ5) at the optical frequency from instantaneously response of carrier phase of envelope results in odd HHG and spectral broadening about each harmonic on the anti-Stokes side of the pump pulse at wo typically in the visible, NIR, and MIR. From the slower molecular Kerr response on femtosecond to picosecond from orientation and molecular motion on n.sub.2 and n.sub.4 which follow the envelope of optical field of the laser gives rise to extreme broadening without HHG. The resulting spectra extend on the Stokes side towards the IR, RF to DC covering most of the electromagnetic spectrum. These HHG and Super broadening covering UUV to X rays and possibly to gamma ray regime for microscopes.

A supercontinuum light source can include a seed laser arranged to provide seed pulses with a pulse frequency F.sub.seed; a pulse frequency multiplier (PFM) arranged to multiply the seed pulses by converting pulses having the pulse frequency F.sub.seed to pump pulses with a pulse frequency F.sub.pump, where F.sub.pump is larger than F.sub.seed; and a non-linear element arranged to receive said pump pulses and convert said pump pulses to pulses of supercontinuum light. The PFM can further include a splitter for splitting pulses into first and second sub beams each having the same pulse frequency, where the PFM is configured such that the sub beams experience different delays; and a combiner for combining said first and second sub beams into a beam having the pulse frequency that is greater than said same pulse frequency. The splitter can have an uneven splitter ratio.

An all-fiber supercontinuum (SC) optical source utilizes a combination of a seed pulse supply of short-duration optical pulses with a highly non-linear optical medium in the form of two or more concatenated sections of highly non-linear optical fiber (HNLF) of different dispersion values and lengths. The two or more sections of HNLF are configured to include at least one section that exhibits a positive dispersion value and one section that exhibits a negative dispersion value. Non-linear effects such as self-phase modulation (SPM), cross-phase modulation (XPM), Raman amplification, and the like, cause the seed pulses to broaden as they propagate through each section of HNLF, where the differences between the dispersion values, as well as the lengths of each fiber section, are particularly configured to create an SC output that is wide and smooth, exhibiting a stable intensity and high coherence level.

A light source, including: a pulse generator for providing an initial sequence of light pulses, the initial sequence of light pulses including an initial number of light pulses within a predetermined time period, first and second optical arms, for propagating, respectively, first and second sequences of light pulses, each derived from the initial sequence of light pulses, wherein the first optical arm includes a first manipulator configured to generate the first sequence of light pulses from the initial sequence of light pulses, wherein the light source includes a nonlinear optical element arranged to receive the first sequence of light pulses or the second sequence of light pulses, and an optical switch arranged to switch that either the first sequence of light pulses or the second sequence of light pulses is received by the nonlinear optical element.

A broadband radiation source device, including a fiber assembly having a plurality of optical fibers, each optical fiber being filled with a gas medium, wherein the broadband radiation source device is operable such that subsets of the optical fibers are independently selectable for receiving a beam of input radiation so as to generate a broadband output from only a subset of the plurality of optical fibers at any one time.