A microheater comprises an optical fiber including a rare earth-doped glass core surrounded by a glass cladding. The rare earth-doped glass core comprises a rare earth dopant at a concentration sufficient for luminescence quenching such that, when the rare earth dopant is pumped with light at an absorption band wavelength, at least about 90% of absorbed pump light is converted into heat.

A microheater comprises an optical fiber including a rare earth-doped glass core surrounded by a glass cladding. The rare earth-doped glass core comprises a rare earth dopant at a concentration sufficient for luminescence quenching such that, when the rare earth dopant is pumped with light at an absorption band wavelength, at least about 90% of absorbed pump light is converted into heat.

A photoirradiation device includes an insertion path for inserting a wire rod; a first reflector having a circular arc shape centered on a point shifted from a center of the insertion path by a first distance, one side of the first reflector facing the insertion path being a reflective surface; a second reflector disposed adjacent open edges of the first reflector and having a circular arc shape centered on a point shifted from the center of the insertion path by a second distance that is different from the first distance, one side of the second reflector facing the insertion path being a reflective surface; and a light source that is positioned on an opposite side of the insertion path from the first reflector and that projects light toward the wire rod.

A microheater comprises an optical fiber including a rare earth-doped glass core surrounded by a glass cladding. The rare earth-doped glass core comprises a rare earth dopant at a concentration sufficient for luminescence quenching such that, when the rare earth dopant is pumped with light at an absorption band wavelength, at least about 90% of absorbed pump light is converted into heat.

A microheater comprises an optical fiber including a rare earth-doped glass core surrounded by a glass cladding. The rare earth-doped glass core comprises a rare earth dopant at a concentration sufficient for luminescence quenching such that, when the rare earth dopant is pumped with light at an absorption band wavelength, at least about 90% of absorbed pump light is converted into heat.

Methods and systems for localized strengthening of features of a component formed from a sapphire material include a combination of holistic heating and localized surface heating. In one example, the localized heating may occur via laser thermal, flame polishing, hot wire heating, plasma etching, or chemical treatment. By combining the localized surface heating with holistic heating, near-melt or melt processing in a localized area can be achieved while avoiding overheating of well-polished areas, and therefore minimizing defects that would otherwise be caused by excessive heating. This may be used for strengthening features of components formed from sapphire material that are difficult to polish, such as non-planar features.

A method for producing a protected optical fiber with distributed sensors includes heating an optical fiber preform and drawing the heated optical fiber preform to form a drawn optical fiber. The method also includes coating the drawn optical fiber with a carbon coating after the optical fiber is drawn to provide a carbon coated optical fiber and then writing a series of fiber Bragg gratings (FBGs) into the carbon coated optical fiber to provide a carbon coated optical fiber with FBGs. The method further includes coating the carbon coated optical fiber with FBGs with one or more layers of a polymer to provide the protected optical fiber with distributed sensors, wherein the heating, drawing, carbon coating the drawn optical fiber, writing, coating the carbon coated optical fiber are performed in that sequence while the protected optical fiber is being produced.

A method for obtaining transient Bragg gratings in optical waveguides and several different applications of the transient Bragg gratings obtained using this method are presented. The basic mechanisms for obtaining the transient gratings in the waveguides are refractive index change due to Kerr nonlinearity, free carrier generation, and gratings formed by linear or non-linear absorption of thermal energy. The exemplary applications include an ultra-fast fiber laser source at any central wavelength, a fast spectral switch/modulator, transient pulse stretchers based on transient chirped gratings, Q-switching based on transient gratings, and time reversal of ultra-short pulses and low power sub-nanosecond pulse generations.

A device for coating a fiber includes a fiber receiving arrangement and a coating arrangement which includes an application unit which wets the fiber with a coating agent, and a curing unit arranged downstream of the application unit which optically cures the coating agent. The curing unit includes a lamp which emits at least one light beam which is aimed directly or indirectly at a surface of the fiber. A main radiation direction of the lamp includes a beam angle between the main radiation direction and a longitudinal direction of the fiber of less than 40. The fiber receiving arrangement and the application unit are movable relative to each other in the longitudinal direction of the fiber via a translational motion arrangement so that a wetting process is implemented substantially along an entire length of the fiber.

A UVLED apparatus (and related system and method) provide efficient curing of an optical-fiber coating on a drawn glass fiber. The apparatus employs one or more UVLEDs that emit electromagnetic radiation into a curing space. An incompletely cured optical-fiber coating, which is formed upon a glass fiber, absorbs emitted and reflected electromagnetic radiation to promote efficient curing.