Improvements to gratings for use in waveguides and methods of producing them are described herein. Deep surface relief gratings (SRGs) may offer many advantages over conventional SRGs and Bragg gratings, an important one being a higher S-diffraction efficiency. In one embodiment, deep SRGs can be implemented as polymer surface relief gratings or evacuated Bragg gratings (EBGs). EBGs can be formed by first recording a holographic polymer dispersed liquid crystal (HPDLC) grating. Removing the liquid crystal from the cured grating provides a polymer surface relief grating. Polymer surface relief gratings have many applications including for use in waveguide-based displays.

A temperature sensor and temperature sensing system for sensing changes m temperature up to a predetermined temperature is disclosed. The temperature sensor includes a microstructured optical fiber where the micro-structured optical fiber includes a plurality of longitudinal channels extending along the microstructured optical fiber. The sensor also includes a fiber Bragg grating formed in the microstructured optical, fiber by generating a periodic modulation in the refractive index along a core region of the microstructured optical fiber. The fiber Bragg grating is operable to produce band reflection at a reflection wavelength that varies in accordance with changes in temperature at the core region of the optical fiber.

There is provided a method for making an optical element having a textured surface. The method comprises the steps of: a) providing a plurality of primary optical fiber segments, each primary fiber segment comprising one or more cores; b) bundling the primary fiber segments into an assembly with the cores of said primary fiber segments extending parallely; c) transforming the assembly into a secondary structure comprising the parallely extending cores; and d) etching a surface of the secondary structure according to an etch profile of said secondary structure, the etch profile being defined by the parallely extending cores, thereby forming the textured surface of the optical element. An optical element having a textured surface is also provided.

An easy-to-fabricate and highly efficient single-mode optical fiber-to-single-mode optical waveguide coupler having relatively large horizontal and vertical alignment tolerances between the fiber and the waveguide coupler. The waveguide coupler also features ease of end-facet cleaving. The waveguide coupler can be used in ultra-broadband high coupling efficiency applications or other suitable applications. Single-mode on-chip waveguides incorporating such coupler(s) are also provided, as are methods of manufacturing the waveguide coupler and on-chip waveguide.

A reactor temperature measurement system includes a Fiber Bragg Grating sensor array arranged in a body of the reactor for monitoring temperatures at multiple positions in an axial direction of the body to obtain temperature sensing optical signals; and a fiber grating demodulator, connected to the Fiber Bragg Grating sensor array, and used to demodulate the temperature sensing optical signals. A method for preparing a Fiber Bragg Grating includes preparing a Fiber Bragg Grating by using a single-mode fiber and annealing the Fiber Bragg Grating, which includes heating the Fiber Bragg Grating to a temperature above 400° C. and maintaining for 100 to 200 hours.

The disclosed embodiments generally relate to extruding multiple layers of micro- to nano-polymer layers in a tubular shape. In particular, the aspects of the disclosed embodiments are directed to a method for producing a Bragg reflector comprising co-extrusion of micro- to nano-polymer layers in a tubular shape.

Embodiments relate to a polymer waveguide including a substrate, a cladding layer made of a first polymer, formed on the substrate, wherein a first monomer is polymerized into the first polymer, and the cladding layer has a groove for the waveguide by removing part of the cladding layer, and a core accommodating graphene therein, formed on the groove, a method for manufacturing the same, and a passively mode-locked laser based on the polymer waveguide.

An optoelectronic device includes a photonic component. The photonic component includes an active side, a second side different from the active side, and an optical channel extending from the active side to the second side of the photonic component. The optical channel includes a non-gaseous material configured to transmit light.

An optical fiber filter includes a fiber core, inner cladding, and outer cladding. A refractive index of the fiber core, a refractive index of the inner cladding, and a refractive index of the outer cladding progressively decrease in sequence. The fiber core is configured to transmit at least two mutually different first optical signal modes, the inner cladding is configured to transmit at least two mutually different second optical signal modes, and at least one fiber grating is etched on the fiber core. At least part of optical power of a target first optical signal mode is coupled to only a target second optical signal mode at the fiber grating. The target first optical signal mode is one of the at least two first optical signal modes, and the target second optical signal mode is one of the at least two second optical signal modes.

The disclosed embodiments generally relate to extruding multiple layers of micro- to nanopolymer layers in a tubular shape. In particular, the aspects of the disclosed embodiments are directed to a method for producing a Bragg reflector comprising co-extrusion of micro- to nanopolymer layers in a tubular shape.