Abstract: A mode multiplexing/demultiplexing optical circuit with a reduced inter-mode crosstalk is provided. A mode multiplexing/demultiplexing optical circuit includes a Port 1 through which light from a light source is input to a waveguide, a Port 3 through which light propagating through a first waveguide is output, a mode conversion unit located adjacent to the first waveguide, and configured to convert a first-order mode light input from the Port 3 to a second-order mode, and Port 2 configured to convert, via a waveguide located adjacent to the mode conversion unit, second-order mode light input to the mode conversion unit to a zeroth-order mode.

Abstract: An optical detection device and method for detecting temperature changes and/or wavelength changes of an optical probe signal includes transmitting an optical probe signal having a predetermined wavelength to an optical input port of an optical waveguide; detecting first and second optical detection signal at first and second optical output ports via first and second opto-electrical converters which create corresponding first and second electrical signals; measuring values of the first and second electrical signal and determining an absolute temperature or a temperature change of the optical waveguide and/or an absolute wavelength value or a wavelength change of the optical probe signal via values measured of the first and second electrical signals and first and second previously determined wavelengths and temperature dependencies of both first and second power transfer functions.

Abstract: Structures including an optical component and methods of fabricating a structure including an optical component. The structure includes a substrate, an optical component including a waveguide core, and a back-end-of-line stack including a heat spreader layer. The optical component is positioned in a vertical direction between the substrate and the back-end-of-line stack. The waveguide core contains a first material having a first thermal conductivity, and the heat spreader layer contains a second material having a second thermal conductivity that is greater than the first thermal conductivity of the first material.

Abstract: The present disclosure is related to transmitting and receiving media channels, such as audio and video channels. These channels may be transmitted as packets from one or more transmitting devices to one or more receiving devices for playout. Certain embodiments of the present disclosure include systems, methods, and computer-readable media for determining latency of a data network for synchronised playout of received signals. Additionally, certain embodiments of the present disclosure include systems, methods, and computer-readable media for synchronising playout among devices connected to a data network.

Abstract: A system can include an optical receiver. The optical receiver can have an optical delay component and at least one electrical component (e.g., diode, resistor and/or transistor) operatively coupled to (e.g., integrated within) the optical delay component. The system can further include a processing device, operatively coupled to a memory, that can tune an amount of optical delay implemented by the optical delay component in a low loss and/or low dispersion manner. For example, the processing device can adjust, based on optical delay tuning data (e.g., built-in self-test (BIST) data), the at least one electrical component to modify at least one property of the at least one optical delay component.

Abstract: A method of rotating polarization of light travelling in a waveguide includes receiving an optical signal having a first polarization state at a first section of the waveguide, the first section of the waveguide being disposed on a plane of a substrate, using a micro-electromechanical system (MEMS) device, angling a second section of the waveguide out of the plane of the substrate, and outputting the optical signal with a second polarization state, different from the first polarization state, on a third section of the waveguide, the third section of the waveguide also being disposed on the plane of the substrate. A control loop is provided to sense the polarization shift to control the angle of the MEMS device to compensate for that shift.

Abstract: Provided are a light detection and ranging (LiDAR) device and a method using the same. The LiDAR device includes a light scanner configured to periodically scan a region in a surrounding area by sequentially changing a traveling path of incident light; a first light source configured to provide a first light to the light scanner in a first incidence direction; and a second light source configured to provide a second light to the light scanner in a second incidence direction different from the first incidence direction.

Abstract: Provided are an apparatus and method of generating a terahertz (THz) signal using a directly-modulated laser. An apparatus of generating a THz signal includes a first directly-modulated laser configured to output a local oscillator (LO) signal, a second directly-modulated laser configured to receive a baseband signal used as data and optically modulate the baseband signal, a band-pass filter configured to filter a spectral component of the baseband signal optically modulated and outputted through the second directly-modulated laser by using a specific frequency bandwidth, a coupler configured to couple the baseband signal filtered through the band-pass filter and the LO signal to each other, and a uni-travelling-carrier photodiode (UTC-PD) configured to generate a THz signal by beating the baseband signal and the LO signal coupled to each other.

Abstract: An interferometer includes a coherent light source and an array of electrically coupled light-sensitive pixel elements. The interferometer is configured to direct an internal optical path of the coherent light source and an external optical path of the coherent light source into a monolithic unit cell. In addition, the monolithic unit cell is configured to direct the internal optical path first through the monolithic unit cell and then onto the array and also configured to direct the external optical path back outside the monolithic unit cell through an external environment and then back into the monolithic unit cell and finally onto the array. In addition, interferometer is further configured to combine the internal optical path and the external optical path at the array and produce a first interferogram on the array, the interferogram characterizing an optical property of the external environment.

Abstract: A polarization scrambler using a retardance element (RE) is disclosed. The polarization scrambler may include an optical fiber input to transmit an optical signal, and a beam expander to receive and expand the optical signal to create an expanded optical signal. The polarization scrambler may include a retardance element (RE) to cause a polarization scrambling effect on the expanded optical signal and to create a scrambled expanded optical signal. The polarization scrambler may include a beam reducer to receive and reduce the scrambled expanded optical signal to create a scrambled optical signal. The polarization to scrambler may include an optical fiber output to receive scrambled optical signal. The optical fiber output may transmit the scrambled optical signal to one or more downstream optical components.

Abstract: A nonlinear fiber interferometer is disclosed suitable for fiber sensor and other applications. A first nonlinear fiber section amplifies probe and conjugate sidebands of a pump through four-wave mixing. A second section introduces a phase shift to be measured, for example from a sensor. A third nonlinear fiber section amplifies with phase-sensitive gain to increase signal-to-noise ratio. Based on phase-sensitive output power of probe and/or conjugate components, the phase shift can be measured. Superior performance can be obtained by balancing gain between the (first and third) nonlinear sections. Non-fiber, for example photonic integrated circuit, embodiments are disclosed. Differential sensing, alternative detection schemes, sensing applications, associated methods, and other variations are disclosed.

Abstract: Device cost and electric power consumption are reduced. Nodes 11a to 11d as optical add/drop multiplexers each include cAWGs 24a and 24b that include a plurality of first side ports and a plurality of second side ports connected between light transmission paths as optical fibers 12 and 13 and transponders 25a to 25n and in which a first optical signal input-output channel interval of each port is a plurality of times larger than a second optical signal input-output channel interval of ports of the transponders 25a to 25n and optical signals of a plurality of different wavelengths from one or a plurality of transponders 25a to 25n or the light transmission paths can pass through a first channel. The cAWGs 24a and 24b cause the optical signals from the transponders 25a to 25n to pass through the first side ports, and then cyclically outputs and transmits the optical signals through the plurality of second side ports in a predetermined order to the light transmission paths.

Abstract: A terahertz polarization beam splitter based on a two-core negative curvature fiber is provided, which relates to the technical field of optical fiber communication. The polarization beam splitter includes: a base circular tube and core separation structures. Multiple large cladding tubes are internally tangent and connected to an inner wall of the base circular tube and arranged at equal intervals along a circumference of the inner wall of the base circular tube, and the multiple large cladding tubes are symmetrically distributed on the inner wall of the base circular tube. Embedded circular tubes are internally tangent and connected to inner walls of the multiple large cladding tubes respectively. The core separation structures are two in number.

Abstract: An optical circuit element formed on a substrate, the optical circuit element includes a first waveguide and a second waveguide, the second waveguide having a shape in a width direction, the shape being asymmetrical to the first waveguide. The first waveguide includes a first segment and a second segment, the first segment having a width that changes along a light propagation direction, the second segment continuous with the first segment. The second waveguide includes a coupled waveguide adjacent to the second segment of the first waveguide. At least one of the second segment and the coupled waveguide has a shape with a width that changes along the light propagation direction.

Abstract: An optical device includes: a ground electrode having a ground potential; a thin film optical waveguide formed by a thin film substrate stacked on the ground electrode; a signal electrode that is arranged at a position facing the ground electrode across the thin film optical waveguide and that transmits a high frequency signal; and a dielectric that covers at least a part of an exposed surface of the signal electrode.

Abstract: The present disclosure provides an optical display system and method, and a display device. The optical display system includes: a display screen; a light split member configured to split light from the display screen into a first polarized light and a second polarized light with different polarization directions; a first optical waveguide configured to guide the first polarized light to a light exit side of the optical display system; and a second optical waveguide located at a light exit side of the first optical waveguide, spaced apart from the first optical waveguide, and configured to at least partially transmit the first polarized light and guide the second polarized light to the light exit side of the optical display system.

Abstract: Various forms of optical circulator are disclosed. The optical circulators act on polarisation of the light to direct light between its ports. Also disclosed are systems and methods for facilitating estimation of a spatial profile of an environment based on a light detection and ranging (LiDAR) based technique. The systems and method may include or use one or more of the various forms of optical circulator. In one arrangement, the present disclosure facilitates spatial profile estimation based on directing light over one dimension, such as along the vertical direction. In another arrangement, by further directing the one-dimensionally directed light in another dimension, such as along the horizontal direction, the present disclosure facilitates spatial profile estimation based on directing light in two dimensions.

Abstract: A first waveguide and a second waveguide including a first layer and a second layer are provided. In a first longitudinal segment, the first layer gradually approaches a first waveguide in a first transverse direction. In a second longitudinal segment, the first and second waveguides are longitudinally oriented. In a third longitudinal segment, the first layer includes a length portion having a width in the first transverse direction that gradually decreases along the third longitudinal segment, and the second layer includes a length portion having a width in the first transverse direction that gradually increases along the third longitudinal segment.

Abstract: A Mach-Zehnder interferometer (MZI) filter comprising one or more passive compensation structures are described. The passive compensation structures yield MZI filters that are intrinsically tolerant to perturbations in waveguide dimensions and/or other ambient conditions. The use of n+1 waveguide widths can mitigate n different sources of perturbation to the filter. The use of at least three different waveguide widths for each Mach-Zehnder waveguide can alleviate sensitivity of filter performance to random width or temperature variations. A tolerance compensation portion is positioned between a first coupler section and a second coupler section, wherein the tolerance compensation portion includes a first compensation section having a second width, a second compensation section having a third width and a third compensation section having a fourth width, wherein the fourth width is greater than the third width and the third width is greater than the second width.

Abstract: A photonic polarization splitter rotator (PSR) includes a substrate, a first optical waveguide disposed in the substrate on a first layer, the first optical waveguide having a curved portion between a first end of the first optical waveguide and a second end of the first optical waveguide, and a second optical waveguide disposed in the substrate on a second layer, above the first layer, the second optical waveguide having a substantially rectangular shape and longitudinally arranged between the first end of the first optical waveguide and the second end of the first optical waveguide.

Abstract: A single-ended output circulator includes a three-core optical fiber head having first, second, and third optical fiber cores; a walk-off crystal having a first surface facing towards the second end of the three-core optical fiber head tube and a second surface facing away from the second end of the three-core optical fiber head tube; a plurality of half-wave plates each having a first surface coupled to the second surface of the walk-off crystal and a second surface facing away from the second surface of the walk-off crystal; a collimating lens having a first end and a second end; a reflection mirror configured to reflect light beams from the collimating lens; an optical prism between the collimating lens and the reflection mirror and configured to transmit a light beam along a propagation direction according to a polarization direction of the light beam; and a polarization rotator.

Abstract: A Faraday rotator and an optical isolator having a high transmittance and a high Verdet constant are provided. The optical isolator includes at least a Faraday rotator that rotates a polarization plane of incident light in a non-reciprocal manner, a polarizer disposed on a light incident side of the Faraday rotator, and an analyzer disposed on a light exit side of the Faraday rotator. The Faraday rotator is made of an oxide containing ytterbium oxide (Yb2O3), and is manufactured by a ceramic manufacturing process, wherein the oxide is allowed to contain an oxide of a metal other than ytterbium, and the proportion of ytterbium in all metal atoms in the oxide is 80% or more.

Abstract: The present disclosure provides a liquid crystal phase shifter array, a driving method thereof, and a laser scanner. The liquid crystal phase shifter array includes a plurality of liquid crystal phase shifter units arranged in array, a first substrate and a second substrate disposed opposite to each other, a liquid crystal layer provided between the first substrate and the second substrate, a first electrode provided on the first substrate, and a second electrode provided on the second substrate. Each liquid crystal phase shifter unit includes a first optical waveguide provided on a side of the first substrate proximal to the liquid crystal layer and arranged to be in direct contact with the liquid crystal layer.

Abstract: Disclosed herein are techniques for improving the light collection efficiency in coaxial LiDAR systems. A coaxial LiDAR system includes a photodetector, a first polarization beam splitter configured to receive a returned light beam including a first linear polarization component and a second linear polarization component and direct the different linear polarization components to different respective directions, a polarization beam combiner configured to transmit the first linear polarization component from the first polarization beam splitter to the photodetector, a non-reciprocal polarization rotator configured to transmit the second linear polarization component from the first polarization beam splitter, and a second polarization beam splitter configured to reflect the second linear polarization component from the non-reciprocal polarization rotator towards the polarization beam combiner.

Abstract: Disclosed herein is an optical filter configured for wavelength division and multiplexing capable of transmitting and receiving signals. The optical filter includes an optical waveguide configured to receive at an input multiple signals with different wavelengths. The optical filter includes a plurality of channels coupled at different locations along a length of the optical waveguide. Each of the plurality of channels is configured to transmit a respective one of the multiple signals. A number of ring filter stages in a first channel of the plurality of channels that is closer to the input of the optical waveguide is greater than a second channel in the plurality of channels further away from the input of the optical waveguide.

Abstract: An optical waveguide device includes first and second waveguides formed parallel to each other. The first waveguide includes a first rib and a first slab. The first slab is formed in a region between the first rib and the second waveguide. The second waveguide includes a second rib, a second slab and a third slab. The second rib is provided between the second slab and the third slab. The first and second slabs are integrally formed. At one end of the optical waveguide device, a first effective refractive index that indicates an effective refractive index of a TEi mode in the first waveguide is higher than a second effective refractive index that indicates an effective refractive index of a TEj mode in the second waveguide. At another end, the first effective refractive index is lower than the second effective refractive index.

Abstract: A semiconductor laser shaping device includes, along the light path of a semiconductor laser, a fast axis collimating lens, slow axis collimating lens, the half wave plate, a polarization beam combining prism, and a crawling prism group. The laser emitted by the semiconductor laser is collimated by a fast-axis collimating lens and then by a slow-axis collimating lens, and subsequently injected into a half wave plate and polarization beam combining prism, which compresses its spot size along the slow axis while keeping the spot size unchanged along the fast axis. The laser beam then passes through the crawling prism group, which shifts a portion of the light in the slow-axis direction to the fast-axis direction, which again compresses the light beam in the slow-axis direction. The device can reduce the beam size of a semiconductor laser in the slow-axis direction, reducing its beam parameter product and improving beam quality.

Abstract: An anti-torsion solid-core polarization-maintaining photonic crystal fiber includes a cladding having an inner layer arranged around the core and an outer layer between the inner layer and the outer wall of the cladding. The inner layer has multi-layer air holes used to construct optical properties and two micron-size air holes arranged along the x-axis extending in the center producing form birefringence. The outer layer includes multi-layer air holes arranged radially along the y-axis. The size and arrangement of the multi-layer air holes in the outer layer cause the bending stiffness of the photonic crystal fiber along the x-axis to be different from that along the y-axis. While meeting the requirements of the optical properties of the fiber, the photonic crystal fiber possesses an anti-torsion ability due to the anisotropy of stress distribution in the radial direction, thereby reducing the non-reciprocal phase difference generated by the magneto-optic Faraday Effect.

Abstract: A polarization recovery device comprises an input that receives a first optical signal with unknown polarization and with at least one signal parameter at an initial value, a first output that outputs a second optical signal with known polarization and with the at least one signal parameter at or near the initial value, and a recovery block that generates the second optical signal based on the first optical signal.

Abstract: The present invention discloses a directional photonic coupler (1) with independent tuning of the coupling factor and phase difference. The coupler comprises: two waveguides (4, 5), with respective propagation constants “?1, ?2”, on which phase shifters (6, 7) configured to modify the propagation coefficients are located. Both phase shifters are configured such that, by independent modification (differential or unique) of the propagation coefficients, the power coupling factor (K) between an input signal (2a or 2b) and the output signals (3b and 3a) is tuned, and by equal and simultaneous modification of the propagation coefficients, the common phase difference of the optical output signals (3 a, 3b) is tuned. A third phase shifter (15) can be used to retune the phase difference at the input/output of one of the waveguides. The coupler is of particular interest in PIC circuits, coupled resonators, Mach-Zehnder interferometers and mesh structures.

Abstract: 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.

Abstract: A Mach-Zehnder interferometer (MZI) filter comprising one or more passive compensation structures are described. The passive compensation structures yield MZI filters that are intrinsically tolerant to perturbations in waveguide dimensions and/or other ambient conditions. The use of n+1 waveguide widths can mitigate n different sources of perturbation to the filter. The use of at least three different waveguide widths for each Mach-Zehnder waveguide can alleviate sensitivity of filter performance to random width or temperature variations. A tolerance compensation portion is positioned between a first coupler section and a second coupler section, wherein the tolerance compensation portion includes a first compensation section having a second width, a second compensation section having a third width and a third compensation section having a fourth width, wherein the fourth width is greater than the third width and the third width is greater than the second width.

Abstract: An optical multiplexer that extends a transmission bandwidth of light is achieved. The present invention provides an optical multiplexer constructed of a multimode waveguide to which two single mode input waveguides are connected at a distance and two single mode output waveguides connected at a distance to a surface opposite a surface to which the input waveguides of the multimode waveguide are connected, in which a width of the multimode waveguide is smaller than widths of the two input waveguides plus a distance between the input waveguides, and the input waveguides are connected to the multimode waveguide and the multimode waveguide is connected to the output waveguides via tapered waveguides, respectively.

Abstract: A device (100) for the excitation of a fiber (150) comprises a first piezo bender actuator (110) and a second piezo bender actuator (120). The device (100) also comprises a connection part (130) which is arranged between the first piezo bender actuator (110) and the second piezo bender actuator (120). The device (100) also comprises a movable fiber (150) which is mounted to the connection part (130).

Abstract: A polarization scrambler using a retardance element (RE) is disclosed. The polarization scrambler may include an optical fiber input to transmit an optical signal, and a beam expander to receive and expand the optical signal to create an expanded optical signal. The polarization scrambler may include a retardance element (RE) to cause a polarization scrambling effect on the expanded optical signal and to create a scrambled expanded optical signal. The polarization scrambler may include a beam reducer to receive and reduce the scrambled expanded optical signal to create a scrambled optical signal. The polarization scrambler may include an optical fiber output to receive scrambled optical signal. The optical fiber output may transmit the scrambled optical signal to one or more downstream optical components.

Abstract: Process margin relaxation is provided in relation to a compensated-for process via a first optical device, fabricated to satisfy an operational specification when a compensated-for process is within a first tolerance range; a second optical device, fabricated to satisfy the operational specification when the compensated-for process is within second tolerance range, different than the first tolerance range; a first optical switch connected to an input and configured to output an optical signal received from the input to one of the first optical device and the second optical device; and a second optical switch configured to combine outputs from the first optical device and the second optical device.

Abstract: Disclosed is an apparatus for single-pixel imaging using quantum light, the apparatus including: a light source which generates a photon pair through spontaneously parametric down conversion of a non-linear crystal and splits the photon pair into an idler photon of first polarized light and a signal photon of second polarized light; a signal processing unit which aligns the signal photon with the first polarized light and modulates the signal photon with a pattern of a spatial light modulator, and sends the modulated signal photon to a target; and a signal detecting unit which simultaneously measures signal photons collected after an interaction of the idler photon and the target to obtain an image.

Abstract: Aspects of the present disclosure are directed to monolithically integrating an optical gyroscope fabricated on a planar silicon platform as a photonic integrated circuit with a MEMS accelerometer on the same die. The accelerometer can be controlled by electronic circuitry that controls the optical gyroscope. The optical gyroscope may have a microresonator ring or a multi-turn waveguide coil. Gaps may be introduced between adjacent waveguide turns to reduce cross-talk and improve sensitivity and packing density of the optical gyroscope.

Abstract: Structures including a grating coupler and methods of forming a structure that includes a grating coupler. The grating coupler includes segments that are spaced along a longitudinal axis. Each segment is inclined relative to the longitudinal axis. Each segment includes a first curved section having a first curvature and a second curved section having a second curvature that is inverted relative to the first curvature.

Abstract: A wavelength dispersion amount estimation apparatus includes a correlation signal generation unit configured to generate, from a receive signal, a first signal including a main signal of the receive signal and a second signal, which includes an image signal corresponding to the main signal, with a shift by a baud rate of the receive signal relative to the first signal in a frequency domain, a correlation calculation unit configured to calculate a cross correlation of the first signal and the second signal, and a dispersion amount calculation unit configured to calculate a wavelength dispersion amount, based on a position of a peak of the cross correlation.

Abstract: An optical waveguide in which a grating coupler is formed, a first pattern region arranged to surround the grating coupler, and a second pattern region arranged to surround the grating coupler are included. The first pattern region and the second pattern region are arranged adjacently. In a periphery of the grating coupler, the first pattern region is formed in a region continuous in a circumferential direction. Similarly, in the periphery of the grating coupler, the second pattern region is formed in a region continuous in the circumferential direction.

Abstract: A mode converter for converting mode of propagating light is provided. The mode converter includes: a mode order conversion unit that includes an input-side first rib unit, an output-side first rib unit that extends along the input-side first rib unit, and a first slab unit arranged between the input-side first rib unit and the output-side first rib unit; and a rib channel conversion unit that includes an output-side second rib unit that is in contact with the output-side first rib unit, a second slab unit that is in contact with the first slab unit and a side surface of the output-side second rib unit, and a third slab unit that is in contact with another side surface of the output-side second rib unit.

Abstract: A fiber laser system includes a high power pump laser, an optical fiber that is aligned to receive output from the high power pump laser. The fiber laser system includes a first pair of orthogonally opposed, periodic electrode structures longitudinally aligned on opposite first and second sides of the optical fiber. The fiber laser system includes a controller that is communicatively coupled to the first pair of periodic electrode structures. The controller performs variable period poling of the first pair of periodic electrode structures to achieve quasi-phase matching (QPM).

Abstract: A waveguide for guiding an electro-magnetic wave comprises: a first waveguide part; and a second waveguide part; wherein the first waveguide part has a first width in a first direction (Y) perpendicular to the direction of propagation of the electro-magnetic wave and the second waveguide part has a second width in the first direction (Y), wherein the second width is larger than the first width; and wherein the first and the second waveguide parts are spaced apart by a gap in a second direction (Z) perpendicular to the first and second planes in which the waveguide parts are formed, wherein the gap has a size which is sufficiently small such that the first and second waveguide parts unitely form a single waveguide for guiding the electro-magnetic wave. The waveguide may be used in numerous applications, such as in a photonic integrated circuit, in a sensor or in an actuator.

Abstract: Large mode area optical fibers include cores that are selected to be smaller than a core size associated with a minimum mode field diameter of a lowest order mode. Cross-sectional shape of such cores can be circular or annular, and a plurality of such cores can be used. Gain regions can be provided in cores or claddings, and selected to produce a selected state of polarization.

Abstract: A photonic integrated circulator can be fabricated by including a plurality of polarizing beam splitters and optical polarization rotators such that two copies of the optical signal are output at a receiver in substantially aligned polarization states. The circulator can be used for facilitating bi-directional communications between photonic integrated circuit devices, which are inherently polarization sensitive, while reducing signal loss.

Abstract: A photodiode including a p-type region and an n-type region formed in a core of a grating coupler is provided. The p-type region and the n-type region are each formed as a region having a rectangular shape extending in an array direction of a grating as seen in plan view and are arranged in a direction orthogonal to the array direction of the grating and parallel to a plane of a substrate. A plurality of the p-type regions and a plurality of the n-type regions are formed and alternately arranged.

Abstract: An OCT system includes an OCT optical system and a reference attachment. The OCT optical system has a beam splitter for splitting light into a measurement optical path and a reference optical path, a photodetector, a first waveguide, a second waveguide, and first connectors provided at end portions of the first waveguide and the second waveguide respectively for indirectly or directly connecting the first waveguide and the second waveguide. The reference attachment has a third waveguide, and second connectors formed at both ends of the third wave guide and configured to be attachable to and detachable from the first connector, and is attached to and detached from the OCT optical system h attaching and detaching each of the second connectors to and from the first connector to change an optical path length of the reference optical path.

Abstract: A polarization controller comprising: (i) an optical fiber, and (ii) a carrier surrounding the optical fiber, the carrier comprising an off-center through hole with at least one collapsed region, such that the optical fiber is situated within the through hole and contacts the at least one collapsed region of the through hole, and the collapsed region exerts pressure on the optical 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.