Abstract: Certain exemplary embodiments can provide a system, machine, device, and/or manufacture adapted for and/or resulting from, and/or a method for, activities that can include and/or relate to, providing a photonic crystal fiber that includes an elongated solid core that extends a length of the photonic crystal fiber and defines a fiber longitudinal axis and an elongated annular cladding extending the length of the photonic crystal fiber and is co-axial with the core.

Abstract: Certain exemplary embodiments can provide a system, machine, device, manufacture, circuit, and/or composition of matter, and/or a method for activities, that can comprise and/or relate to, a polarization-maintaining photonic crystal fiber comprising an elongated guiding core and/or an elongated photonic crystal cladding surrounding the core, the cladding defining a plurality of holes.

Abstract: Certain exemplary embodiments can provide a system, machine, device, manufacture, circuit, and/or composition of matter, and/or a method for activities, that can comprise and/or relate to, a polarization-maintaining photonic crystal fiber comprising an elongated guiding core and/or an elongated photonic crystal cladding surrounding the core, the cladding defining a plurality of holes.

Abstract: A hollow-core fiber with a single layer of robust anti-resonant optical arches is disclosed, which is designed and made of infrared soft glass and allows the transmission of mid- to long-infrared wavelengths (1-15 microns). Each curved arch is solidly attached at two locations on the outer solid region surface and together the arches define the core diameter. The thickness and spacing between the arches are selected to minimize the fiber transmission loss <1 dB/m at wavelengths in the mid- to long-infrared where the infrared soft glass has high absorption >30 dB/m. A hollow-core preform with anti-resonant arches is made by extrusion of infrared soft glasses through a die specifically designed to produce the hollow-core fiber with anti-resonant arches.

Abstract: A hollow-core fiber with a single layer of robust anti-resonant optical arches is disclosed, which is designed and made of infrared soft glass and allows the transmission of mid- to long-infrared wavelengths (1-15 microns). Each curved arch is solidly attached at two locations on the outer solid region surface and together the arches define the core diameter. The thickness and spacing between the arches are selected to minimize the fiber transmission loss <1 dB/m at wavelengths in the mid- to long-infrared where the infrared soft glass has high absorption >30 dB/m. A hollow-core preform with anti-resonant arches is made by extrusion of infrared soft glasses through a die specifically designed to produce the hollow-core fiber with anti-resonant arches.

Abstract: A fiber-optic termination with Brewster angled tip is disclosed, which allows minimizing the reflection loss of a polarized light while maximizing the coupling of the refracted polarized light along the axis of the optical fiber. In a preferred embodiment, the fiber-optic termination has a Brewster angled tip which is free standing in air. The holding fixture may be water cooled to evacuate any heat that can occur at the input end of the optical fiber. Further embodiments include fiber array made of multiple fiber-optic terminations with Brewster angled tips for switching applications for example.

Abstract: A laser beam delivery system is disclosed, which allows transmission of high-power infrared light through a hollow core photonic band gap (HC-PBG) fiber made of non-silica-based glass. In this system, the infrared beam first passes through input coupling optics which focus the beam onto the hollow core of the HC-PBG fiber. In front of the input end of the HC-PBG fiber, there is provided a mask with a hole aligned with the hollow core, and the infrared beam first passes through this hole before entering the hollow core of the HC-PBG fiber. This protects the photonic band gap structure from being damaged by the beam. After passing through the HC-PBG fiber, which may be from one to several hundred meters in length, the infrared beam exits at the output end of the fiber and passes through output coupling optics which collimate and focus the beam onto a desired target.

Abstract: A large mode field diameter optical fiber is disclosed. It is a single mode optical fiber which has a core and a cladding. The core of this fiber has two regions, an inner core region and an outer core region which has a refractive index lower than that of the inner core region. The inner core region is doped with a rare-earth element, such as Er2O3, and a co-dopant, such as Al2O3, and the outer core region is doped with a dopant such as GeO2. The types and amounts of the dopants and co-dopants are adjusted to obtain a fiber with a mode field diameter greater than 5.5 ?m at a wavelength of 1550 nm.

Abstract: A large mode field diameter optical fiber is disclosed. It is a single mode optical fiber which has a core and a cladding. The core of this fiber has two regions, an inner core region and an outer core region which has a refractive index lower than that of the inner core region. The inner core region is doped with a rare-earth element, such as Er2O3, and a co-dopant, such as Al2O3, and the outer core region is doped with a dopant such as GeO2. The types and amounts of the dopants and co-dopants are adjusted to obtain a fiber with a mode field diameter greater than 5.5 ?m at a wavelength of 1550 nm.

Abstract: Disclosed is an optical device which combines a controlled level of attenuation, a high degree of wavelength insensitivity and a substantial decrease in modal interference problems. The optical device has a core having a core diameter and a core refractive index; an inner cladding having an inner cladding outer diameter less than ten times the core diameter and a refractive index less that the core refractive index; and an outer cladding having a refractive index higher that the inner cladding refractive index. At least one part of the core, the inner cladding or the outer cladding is doped with at least one absorbing element. Preferably, the core is doped with cobalt in an appropriate concentration, providing the same degree of attenuation at 1310 nm and 1550 nm, while also considerably reducing modal interference. The optical device can be used as an attenuator between a transmission fiber and a detection fiber or can be used to couple a transmission fiber directly to a detector.