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.

A terahertz hollow core waveguide includes several successively cascaded waveguide units, and the waveguide units includes fiber core and cladding. The fiber core is composed of air, and the cladding is composed of dielectric rings, air rings, support strips, and an outer cladding. The medium rings and the air rings are successively surrounded on the outside of the fiber core, and the outer cladding is surrounded on the outside of the outermost air ring. All support strips in the same air ring of the same waveguide unit form a support strip group, and the support strips in the support strip group are arranged along the circumferential direction to connect two adjacent dielectric rings in the same waveguide unit or to connect the outermost dielectric ring and the outer cladding in the same waveguide unit.

An optical fiber has corrugations on an outer surface to dissipate a portion of an input light beam, allowing the remaining portion of the light beam to be coupled to the optical fiber. By dissipating the portion of input light, damage to the optical fiber by uncoupled light is reduced.

The present disclosure discloses a polarization-maintaining hollow-core antiresonant fiber. An inner layer of the polarization-maintaining hollow-core antiresonant fiber includes first thin walls, second thin walls, and third thin walls. The present disclosure introduces high birefringence through the wall thickness difference between the first thin wall and the second thin wall, and effectively amplifies a birefringence effect achieved by the wall thickness difference through quasi multi-symmetric structures of the first thin walls and the second thin walls. In addition, the present disclosure reduces the transmission loss and suppresses the leakage of light through the inner layer, particularly, the third thin walls of the inner layer, so that the fiber of the present disclosure realizes polarization maintaining, and meanwhile, reduce the loss as far as possible.

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.

A hollow core fiber (HCF) link is characterized by structural properties selected to support and sustain light propagation in a fundamental mode and in at least one higher-order mode. Connected to a proximal end of the HCF link, there is a mode coupler configured to couple a data signal into the fundamental mode and to couple an obfuscating signal into the at least one higher-order mode for simultaneous propagation of the data signal and the obfuscating signal on the HCF link, where the obfuscating signal substantially overlaps the data signal in spectral content. At a distal end of the HCF link, there is a mode splitter configured to split a first optical signal detected in the fundamental mode from a second optical signal detected in the at least one higher-order mode.

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.

An optical fiber has corrugations on an outer surface to dissipate a portion of an input light beam, allowing the remaining portion of the light beam to be coupled to the optical fiber. By dissipating the portion of input light, damage to the optical fiber by uncoupled light is reduced.

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.

A terahertz hollow core waveguide includes several successively cascaded waveguide units, and the waveguide units includes fiber core and cladding. The fiber core is composed of air, and the cladding is composed of dielectric rings, air rings, support strips, and an outer cladding. The medium rings and the air rings are successively surrounded on the outside of the fiber core, and the outer cladding is surrounded on the outside of the outermost air ring. All support strips in the same air ring of the same waveguide unit form a support strip group, and the support strips in the support strip group are arranged along the circumferential direction to connect two adjacent dielectric rings in the same waveguide unit or to connect the outermost dielectric ring and the outer cladding in the same waveguide unit.