Embodiments of the current disclosure include small diameter single-mode optical fibers having gratings and methods of forming thereof. In some embodiments, methods of forming a small diameter single-mode optical fibers having gratings include providing an optical fiber having a core and cladding with a combined outer diameter of 100 μm to 125 μm and a coating having a thickness of less than or equal to 20 μm, wherein the coating comprises one of: (i) a high-modulus coating layer surrounding the cladding region; or (ii) a low-modulus coating layer surrounding the cladding region and a high-modulus coating layer surrounding the low-modulus coating layer; and exposing the core, through the coating, to a pattern of ultraviolet radiation to form an optical grating within the core.

Fiber laser having a monolithic laser resonator having laser affected zones for providing laser beams having wavelengths below 800 nm and from between 400 nm to 800 nm. Methods of using femtosecond lasers to form fiber Bragg gratings, volume Bragg gratings, space gratings, and laser beam delivery patterns for changing the index of refraction within optical fibers.

Embodiments of the current disclosure include small diameter single-mode optical fibers having gratings and methods of forming thereof. In some embodiments, methods of forming a small diameter single-mode optical fibers having gratings include providing an optical fiber having a core and cladding with a combined outer diameter of 100 μm to 125 μm and a coating having a thickness of less than or equal to 20 μm, wherein the coating comprises one of: (i) a high-modulus coating layer surrounding the cladding region; or (ii) a low-modulus coating layer surrounding the cladding region and a high-modulus coating layer surrounding the low-modulus coating layer; and exposing the core, through the coating, to a pattern of ultraviolet radiation to form an optical grating within the core.

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.

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 shape sensing system for an anthropomorphic test device is disclosed that includes a plurality of body parts and at least one optical fiber that has a plurality of cores in a spaced and parallel relationship with one another that extend between ends of the optical fiber for sensing positions of the body parts. Each of the cores have a plurality of grating sensors disposed along a length thereof capable of determining a position and orientation of the body parts.

An optical fiber system for a body part of an anthropomorphic test device is disclosed that includes at least one body part and at least one optical fiber that has a plurality of cores in a spaced and helical relationship with one another that extend between ends of the optical fiber for sensing positions of the at least one body part. Each of the cores have a plurality of grating sensors disposed along a length thereof capable of determining a position and orientation of the body part.

An optical coupler device comprises an optical waveguide having a first edge and an opposing second edge that extend in a direction substantially parallel to a propagation direction of an input light beam injected into the optical waveguide. A grating structure is on a portion of the optical waveguide, with the grating structure having a first side and an opposing second side. The first and second sides of the grating structure extend in the same direction as the first and second edges of the optical waveguide. An optical slab adjoins with the first side of the grating structure and is in optical communication with an output of the grating structure. The grating structure includes an array of grating lines configured to diffract the input light beam into the slab at an angle with respect to the propagation direction, such that a diffracted light beam is output from the slab.

An optical coupler device comprises an optical waveguide having a first edge and an opposing second edge that extend in a direction substantially parallel to a propagation direction of an input light beam injected into the optical waveguide. A grating structure is on a portion of the optical waveguide, with the grating structure having a first side and an opposing second side. The first and second sides of the grating structure extend in the same direction as the first and second edges of the optical waveguide. An optical slab adjoins with the first side of the grating structure and is in optical communication with an output of the grating structure. The grating structure includes an array of grating lines configured to diffract the input light beam into the slab at an angle with respect to the propagation direction, such that a diffracted light beam is output from the slab.

Fiber laser having a monolithic laser resonator having laser affected zones for providing laser beams having wavelengths below 800 nm and from between 400 nm to 800 nm. Methods of using femtosecond lasers to form fiber Bragg gratings, volume Bragg gratings, space gratings, and laser beam delivery patterns for changing the index of refraction within optical fibers.