Abstract: 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 cm3 per cm of length of said hollow-core photonic crystal fiber.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A hollow-core photonic crystal fiber (HC-PCF) (10) for guiding at least one mode of a light field (1) along a mode guiding section (11) of the HC-PCF (10), comprises an outer jacket (12), an inner cladding (13) and a hollow core (14), which extend along the HC-PCF (10), wherein the inner cladding (13) is arranged on an interior surface of the outer jacket (12) and comprises anti-resonant structures (15) surrounding the hollow core (14), and the hollow core (14) has a mode guiding core diameter (d) provided along the mode guiding section of the HC-PCF (10), and wherein at least one fiber end (16) of the HC-PCF (10) has a light field coupling section (17) in which the hollow core (14) is tapered over an axial coupling section length from a fiber end core diameter (D) at the at least one fiber end (16) to the mode guiding core diameter (d). Furthermore, methods of using the HC-PCF and manufacturing the HC-PCF are described.

Abstract: Optical components and methods of manufacture thereof. A first optical component has a hollow-core photonic crystal fiber includes internal capillaries for guiding radiation and an outer capillary sheathing the internal capillaries; and at least an output end section having a larger inner cross-sectional dimension over at least a portion of the output end section than an inner cross-sectional dimension of the outer capillary along a central portion of the hollow-core photonic crystal fiber prior to the output end section. A second optical component includes a hollow-core photonic crystal fiber and a sleeve arrangement.

Abstract: 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.

Abstract: A mode control system and method for controlling an output mode of a broadband radiation source including a photonic crystal fiber (PCF). The mode control system includes at least one detection unit configured to measure one or more parameters of radiation emitted from the broadband radiation source to generate measurement data, and a processing unit configured to evaluate mode purity of the radiation emitted from the broadband radiation source, from the measurement data. Based on the evaluation, the mode control system is configured to generate a control signal for optimization of one or more pump coupling conditions of the broadband radiation source. The one or more pump coupling conditions relate to the coupling of a pump laser beam with respect to a fiber core of the photonic crystal fiber.

Abstract: A system and method for providing a radiation source is disclosed. In one arrangement, the radiation source includes a gas cell having a window, an optical fiber that is hollow and has an axial direction, an end thereof being enclosed within the gas cell and optically coupled to the window via an optical path, and a surface, disposed around the end of the optical fiber, and extending past the end of the optical fiber in the axial direction towards the window so as to limit one or more selected from: the exchange of gas between the optical path and the remainder of the gas cell, ingress of plasma towards or into the optical fiber, and/or radical flux towards etch-susceptible surfaces.

Abstract: 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.

Abstract: 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.

Abstract: A mounted hollow-core fiber arrangement includes a hollow-core fiber having a microstructure, and a mount arrangement including a plurality of mounting contacts configured to apply a force to an outer layer of the hollow-core fiber. A portion of the hollow-core fiber is located in a receiving region of the mount arrangement. The plurality of mounting contacts are positioned around the receiving region. The mounting contacts are distributed around the receiving region, the distribution of the mounting contacts corresponding to a distribution of features of the microstructure of the hollow-core fiber. The mounted hollow core fiber can be used in a radiation source apparatus for providing broadband radiation.

Abstract: 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.

Abstract: An apparatus (100) for receiving input radiation (108) and broadening a frequency range of the input radiation so as to provide broadband output radiation (110). The apparatus comprises a fiber (102), wherein the fiber (102) may comprise a hollow core (104) for guiding radiation propagating through the fiber (102). The apparatus (100) further comprises an apparatus for providing a gas mixture (106) within the hollow core (104). The gas mixture (106) comprises a hydrogen component, and a working component, wherein the working component is for broadening a frequency range of a received input radiation (108) so as to provide the broadband output radiation (110). The apparatus may be included in a radiation source.

Abstract: 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 cm3 per cm of length of said hollow-core photonic crystal fiber.

Abstract: A broadband light source device for creating broadband light pulses includes a hollow-core fiber and a pump laser source device. The hollow-core fiber is configured to create the broadband light pulses by an optical non-linear broadening of pump laser pulses. The hollow-core fiber includes a filling gas, an axial hollow light guiding fiber core configured to support core modes of a guided light field, and an inner fiber structure surrounding the fiber core and configured to support transverse wall modes of the guided light field. The pump laser source device is configured to create and provide the pump laser pulses at an input side of the hollow-core fiber. The transverse wall modes include a fundamental transverse wall mode and second and higher order transverse wall modes.

Abstract: A broadband light source device (100) for creating broadband light pulses (1) comprises a hollow-core fiber (10) of non-bandgap type including a filling gas and being arranged for creating the broadband light pulses (1) by an optical nonlinear broadening of pump laser pulses (2), wherein the hollow-core fiber (10) has an axial hollow light guiding fiber core (11), which supports core modes of a guided light field, and an inner fiber structure (12), which surrounds the fiber core (11) and which supports transverse wall modes of the guided light field, and a pump laser source device (20) being arranged for creating and providing the pump laser pulses (2) at an input side (13) of the hollow-core fiber (10), wherein the transverse wall modes include a fundamental transverse wall mode and second and higher order transverse wall modes, the broadband light pulses (1) have a core mode spectrum being determined by a fiber length, a fiber core diameter, at least one pump pulse and/or beam parameter of the pump laser pu

Abstract: A hollow-core photonic crystal fiber (HC-PCF)(10) for guiding at least one mode of a light field(1) along a mode guiding section(11) of the HC-PCF(10), comprises an outer jacket(12), an inner cladding(13) and a hollow core(14), which extend along the HC-PCF(10), wherein the inner clad-ding(13) is arranged on an interior surface of the outer jacket(12) and comprises anti-resonant structures(15) surrounding the hollow core(14), and the hollow core(14) has a mode guiding core diameter(d) provided along the mode guiding section of the HC-PCF(10), and wherein at least one fiber end (16) of the HC-PCF(10) has a light field coupling section(17) in which the hollow core(14) is tapered over an axial coupling section length from a fiber end core diameter(D) at the at least one fiber end (16) to the mode guiding core diameter(d). Furthermore, methods of using the HC-PCF and manufacturing the HC-PCF are described.

Abstract: A broadband light source device (100) for creating broadband light pulses (1) comprises a hollow-core fiber (10) of non-bandgap type including a filling gas and being arranged for creating the broadband light pulses (1) by an optical nonlinear broadening of pump laser pulses (2), wherein the hollow-core fiber (10) has an axial hollow light guiding fiber core (11), which supports core modes of a guided light field, and an inner fiber structure (12), which surrounds the fiber core (11) and which supports transverse wall modes of the guided light field, and a pump laser source device (20) being arranged for creating and providing the pump laser pulses (2) at an input side (13) of the hollow-core fiber (10), wherein the transverse wall modes include a fundamental transverse wall mode and second and higher order transverse wall modes, the broadband light pulses (1) have a core mode spectrum being determined by a fiber length, a fiber core diameter, at least one pump pulse and/or beam parameter of the pump laser pu