Abstract: A system and method for determining information about an assay. In one embodiment the method includes positioning a filter assembly, having an assay disposed on its surface, relative to a light source such that light from the light source is incident on the filter assembly and at least a portion of the light incident on the filter assembly is reflected from the filter assembly, illuminating the filter assembly with light from the light source, receiving light reflected from the filter assembly in an optical element, analyzing one or more characteristics of the light received in the optical element to determine information about a reaction in the assay, wherein a reaction in the assay results in a change of one or more characteristics of the light received from the filter assembly.

Abstract: An optically active fiber (30) is disclosed for making a fiber laser (18) or an amplifier (16). This double-clad structured active fiber (30) has a core (34), doped with an optically excitable ion having a three-level transition. The core (34) has a core refractive index and a core cross-sectional area. An inner cladding (32) surrounds the core (34). The inner cladding (32) has an inner cladding refractive index less than the core refractive index, an inner cladding cross-sectional area between 2 and 25 times greater than that of the core cross-sectional area, and an aspect ratio greater than 1.5:1. An outer cladding (36) surrounds the inner cladding (32) and has an outer cladding refractive index less than the inner cladding refractive index.

Abstract: An optically active waveguide laser (30) includes a multimode portion (126) for carrying more than one spatial mode at a predetermined wavelength chosen from a bandwidth including a pump wavelength (64) and the lasing wavelength (66). The multimode portion (126) has a first refractive index. A cladding portion (386) is proximate the multimode portion (126). A multimode grating (60, 56, or 62) is written on at least one section (26) of the multimode portion for reflecting the predetermined wavelength.

Abstract: An optical amplifier includes a demultiplexer which separates a broadband optical signal into a plurality of banded optical signals; a plurality of ports, each of which outputs a selected one of the plurality of banded optical signals; and an amplifier section which is coupled to one of the plurality of output ports.

Abstract: An optically active phosporus-silicate glass when pumped to directly excite Er ions, provides gain in 1565 nm to 1620 nm range and comprises in weight percent: SiO2 50 to 92%; Er2O3 0.01 to 2%; P2O5 greater than 5%; and Al2O3 0.0 to 0.3%.

Abstract: A semiconductor laser having an external cavity including a single-mode optical fiber. A Bragg grating is written onto the fiber which defines the end of the optical cavity, selects the lasing wavelength, and discriminates against the lasing of higher-order transverse modes in the multi-mode gain region. In one embodiment, the semiconductor laser includes an optically active vertical-cavity semiconductor stack similar to a vertical-cavity surface emitting laser. The stack is optically pumped either from the front or the back over a relatively large area such a multi-mode beam is output. Optics couple the multi-mode beam to the single-mode input of the fiber. A partially transmissive mirror of reflectivity between 25 and 40% may be placed on the output surface of the semiconductor stack to form a coupled-cavity laser. A plurality of laser diodes can be angularly positioned around the area of the semiconductor stack being pumped to increase the total pump power.

Abstract: The disclosed invention includes an amplifier fiber and methods of making the amplifier fiber. One embodiment of the inventive fiber includes a glass core and a glass cladding layer surrounding the glass core. The cladding glass layer has a refractive index which is less than a refractive index of the glass core. The fiber also includes a glass overclad layer surrounding the cladding layer. The overclad layer has a refractive index which is greater than the refractive index of the cladding layer. In another embodiment of the inventive fiber, the overclad layer is doped with an absorber. The absorber strips a mode of light propagating in the cladding from the cladding layer.

Abstract: An optical transmission system is provided comprising a thulium doped optical fiber, a light emitting pump device optically coupled to the thulium doped fiber, and a Raman amplifier fiber optically coupled to the thulium doped optical fiber. The light emitting pump device in combination with the thulium doped fiber generates a first amplification pump wavelength and the Raman amplifier receives the first amplification pump wavelength. The first pump wavelength amplifies an optical signal in the Raman amplifier, the Raman amplifier operating at a signal wavelength in the range of about 1530 nm to about 1625 nm.

Abstract: An optically active waveguide laser (30) includes a multimode portion (126) for carrying more than one spatial mode at a predetermined wavelength chosen from a bandwidth including a pump wavelength (64) and the lasing wavelength (66). The multimode portion (126) has a first refractive index. A cladding portion (386) is proximate the multimode portion (126). A multimode grating (60, 56, or 62) is written on at least one section (26) of the multimode portion for reflecting the predetermined wavelength.

Abstract: An optically active fiber (30) is disclosed for making a fiber laser (18) or an amplifier (16). This double-clad structured active fiber (30) has a core (34), doped with an optically excitable ion having a three-level transition. The core (34) has a core refractive index and a core cross-sectional area. An inner cladding (32) surrounds the core (34). The inner cladding (32) has an inner cladding refractive index less than the core refractive index, an inner cladding cross-sectional area between 2 and 25 times greater than that of the core cross-sectional area, and an aspect ratio greater than 1.5:1. An outer cladding (36) surrounds the inner cladding (32) and has an outer cladding refractive index less than the inner cladding refractive index.

Abstract: An L-band optical amplifier has a rare earth doped gain medium including a filter distributed over a finite physical portion of the gain medium. The filter is distributed over between about 25% to substantially the entire length of the gain medium. The distributed filter substantially eliminates out-of-band light emission (C-band ASE, 1520 nm-1565 nm) and thus improves the performance of L-band amplification (1565 nm-1620 nm). Examples of distributed filters include discrete type filters such as long period gratings, or continuous type filters such as rare earth doped, twin core fibers, non-adiabatically tapered fibers and coaxial resonant ring fibers.

Abstract: An L-band optical amplifier has a rare earth doped gain medium including a filter distributed over a finite physical portion of the gain medium. The filter is distributed over between about 25% to substantially the entire length of the gain medium. The distributed filter substantially eliminates out-of-band light emission (C-band ASE, 1520 nm-1565 nm) and thus improves the performance of L-band amplification (1565 nm-1620 nm). Examples of distributed filters include discrete type filters such as long period gratings, or continuous type filters such as rare earth doped, twin core fibers, non-adiabatically tapered fibers and coaxial resonant ring fibers.

Abstract: The disclosed invention includes an amplifier fiber and methods of making the amplifier fiber. One embodiment of the inventive fiber includes a glass core and a glass cladding layer surrounding the glass core. The cladding glass layer has a refractive index which is less than a refractive index of the glass core. The fiber also includes a glass overclad layer surrounding the cladding layer. The overclad layer has a refractive index which is greater than the refractive index of the cladding layer. In another embodiment of the inventive fiber, the overclad layer is doped with an absorber. The absorber strips a mode of light propagating in the cladding from the cladding layer.

Abstract: A tapered fiber laser having a multi-mode section, a single-mode section, and either a tapered section or fundamental mode matching junction therebetween. The multi-mode section has a large core to directly receive pump light from a broad stripe laser or diode bar, and a length preferably longer than the absorption length of the pump light (so optical amplification occurs predominantly in the multi-mode section). Doping levels can be increased to reduce the multi-mode length. The taper angle is sufficiently small to produce adiabatic compression of the fundamental mode from the multi-mode to single-mode sections, and acts as a cutoff filter favoring lasing of the fundamental mode within the multi-mode section. Alternately, the step junction may have a mode field diameter matched to the lowest-order mode, with laser light output via the single-mode section.

Abstract: An optical amplifier for amplifying signals of different wavelengths throughout a spectral window modifies the amplification of each signal such that the output levels of the signals are more equal than the input levels thereof when the input levels differ by more than a predetermined amount. In one embodiment this is achieved by providing a dichroic reflector at one end of an amplifying fibre so that standing wave patterns are set up in the amplifying fibre by interference of the forward and reflected signal lights, at the different wavelengths, the signal at each wavelength preferentially decreasing its own gain with increasing signal level.