The disclosure relates generally to optical systems, and more particularly, optical systems for temporal compression or stretching of optical pulses.

A sensing textile includes at least one assembly of optical fiber filaments, wherein the sensing textile has a main direction and a cross direction, and wherein the at least one assembly of optical fiber filaments is oriented at any angle measured relative to the cross direction.

An optical force sensor along with an optical processing apparatus and method are disclosed. The optical force sensor includes an optical fiber, a core included in the optical fiber, an instrument including the optical fiber, the instrument having a distal region, and a tubular structure encasing an end of the optical fiber and secured to the first conduit at the distal region of the instrument. When an optical interferometric system is coupled to the optical fiber, it processes reflected light from a portion of the core included within the tubular structure that does not include Bragg gratings to produce a measurement of a force present at the distal region of the instrument.

The optical fiber coupler array can be capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array can be configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. Advantageously, the refractive indices and sizes of both inner and outer core, and/or other characteristics of vanishing core waveguides in the optical coupler array can be configured to reduce the back reflection for light propagating from the plurality of the optical fibers at the coupler first end to the optical device at the coupler second end, and/or vice versa.

An opening and closing detection sensor of the present invention includes a fixed base, a moving base, an optical fiber, and a moving member. The moving base is disposed so as to be movable relative to the fixed base. The optical fiber includes an FBG part where a Bragg wavelength varies responding to an interval between the fixed base and the moving base. The moving member moves between a first position corresponding to either one of an opened state or a closed state of an object and a second position corresponding to the other state. The moving member includes a locking part. The locking part abuts on the moving base between a third position located between the first position and the second position, and the second position, thereby moving the moving base together with the moving member, and moving the moving base in a direction separated from the fixed base.

Shape sensing with a multi-core fiber can achieve high accuracy as well as accommodate small bend radii by measuring signals with peripheral waveguide cores placed at multiple different radial distances from the center axis of the fiber, and computing strain metrics from signals of cores selected based on the respective radial distances and a determination of whether the waveguide cores have strained out of range.

An optical fiber with one or more microgratings is disclosed. Methods and apparatus are described for making an optical fiber with one or more microgratings. Methods and apparatus are described for an optical fiber with one or more microgratings Optical sensing methods and an optical sensing system effectively decouple strain range from the laser tuning range, permit the use of a smaller tuning range without sacrificing strain range, and compensate for ambiguity in phase measurements normally associated with smaller tuning ranges.

A method for forming a pressure sensor is provided wherein an optical fibre is provided, the optical fibre comprising a core, a cladding surrounding the core, and a birefringence structure for inducing birefringence in the core. The birefringence structure comprises first and second holes enclosed within the cladding and extending parallel to the core. A portion of the optical fibre comprising of the core and the birefringence structure is encased within a chamber, wherein the chamber is defined by a housing comprising a pressure transfer element for equalising pressure between the inside and the outside of the housing. An optical sensor is provided along the core of the optical fibre. The cladding is internally etched by flowing an etchant through the first and second holes along a length of the portion of optical fibre which comprises the optical sensor so as to increase the width of the first and second holes. The chamber is filled with a substantially non-compressible fluid. Consequently, the etched cladding is shaped so as to convert an external pressure provided by the non-compressible fluid within the chamber to an anisotropic stress in the optical sensor.

Optical arrangements for processing a workpiece include a fiber laser arrangement for emitting laser radiation, a fiber arrangement directly coupled to the fiber laser arrangement and configured to guide the laser radiation in a direction to the workpiece to be processed, the fiber arrangement including a transport fiber having a fiber core and at least one fiber cladding surrounding the fiber core, and at least one coupling device for coupling a portion of the laser radiation guided in the fiber arrangement into at least one fiber cladding of the transport fiber. The coupling device has a spectral bandwidth of at least the same magnitude as a spectral bandwidth of the laser radiation. The fiber laser arrangement is configured to change a beam profile of the guided laser radiation to shift the spectral bandwidth of the laser radiation relative to the spectral bandwidth of the coupling device.

A curvature sensor includes a light source, a flexible light guide including cores, and FBG sensors that are provided in the cores and constitute FBG sensor groups at predetermined positions at predetermined positions along longitudinal axes of the cores. The curvature sensor includes a detector that detects an optical spectrum of light from the FBG sensors, and a processor that obtains a bend of the light guide. FBG sensors provided in a core include a first FBG sensor and a second FBG sensor next to it. The first and second FBG sensors include gratings having first and second pitches. The first pitch is shorter than the second pitch and is closer to the second pitch than other pitches of gratings of all FBG sensors that are provided in the core and include gratings having pitches shorter than the second pitch.