A supercontinuum source may include a seed source providing seed light, where the seed source includes one or more seed lasers to generate the seed light and a seed controller to adjust at least one of a temporal pulse profile or a wavelength of the seed light. The supercontinuum source may further include an optical fiber to receive the seed light, where the seed source pumps the optical fiber to induce the generation of supercontinuum output light, and where a spectrum of the supercontinuum output light is controllable by adjusting at least one of the temporal pulse profile or the wavelength of the seed light with the seed controller.

A method for generating gigahertz bursts of laser pulses is provided, where: 1) time delay T2 of the delayed part with respect to the undelayed part of the input pulse is longer than a time period T1 between said input pulse and the next input pulse; 2) the bursts of output pulses have an incrementally increasing number of pulses; 3) intra-burst pulse separation inside the formed bursts is equal to T3=T2−T1 and corresponds to an ultra-high pulse repetition rate higher than 100 MHz. In another embodiment: 1) T2 is longer than M*T1, where M=2, 3, etc.; 2) output train of bursts is composed of bursts of pulses wherein M adjacent bursts have identical number of pulses; 3) T3 is equal to T3=T2−M*T1. The laser apparatus for implementing the method is provided.

An optical semiconductor device outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The optical semiconductor device includes a separate confinement heterostructure layer positioned between the quantum well active layer and the n-type cladding layer. The optical semiconductor device further includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and the n-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The optical semiconductor device is applied to a ridge-stripe type laser.

A laser processing apparatus includes a semiconductor laser element, a waveform output unit for outputting input waveform data, a driver circuit for supplying a drive current having a time waveform according to the input waveform data to the semiconductor laser element, and a processing optical system for irradiating a processing object with laser light. The semiconductor laser element outputs the laser light in which two or more light pulse groups each including one or a plurality of light pulses are provided with a time interval therebetween. Time waveforms of at least two light pulse are different from each other. The time waveform includes at least one of a time waveform of each of the one or plurality of light pulses, a time width of each of the one or plurality of light pulses, and a time interval of the plurality of light pulses.

A seed laser is configured to emit seed laser light. A plurality of optical amplifiers is configured to generate amplified laser light by amplifying the seed laser light. Each of the optical amplifiers is configured to separately direct its respective amplified laser light to a medium without being optically combined within the laser assembly with any of the other amplified laser light emitted by other optical amplifiers in the plurality of optical amplifiers.

A Raman pumping device (10) for amplifying a data optical signal in a fiber optic transmission system, comprising first and second ports (12a, 12b) through which the data optical signal may respectively enter and exit the Raman pumping device (10), a Raman pump source (14) for generating a Raman pump signal, and at least one combiner (16) for combining the Raman pump signal with the data optical signal. The Raman pumping device (10) allows for selectively combining the Raman pump signal generated by the same Raman pump source (14), or at least parts of the same Raman pump source (14) codirectionally or counterdirectionally with the data optical signal.

An optically amplified repeater system includes optical transmission paths, a multi-channel optical amplifier, one or more Raman amplification pumping light sources, and a wavelength multiplexer. The multi-channel optical amplifier includes K simultaneous pumping light sources, N optical amplification media, and one or more optical couplers, and simultaneously amplifies, with the K simultaneous pumping light sources, light intensities of optical signals that pass through the N optical amplification media and propagate through the optical transmission paths. Light intensities of the wavelength band of the optical signals is Raman amplified by the Raman amplification pumping light. A light intensity of the Raman amplification pumping light output from the one or more Raman amplification pumping light sources is determined in accordance with characteristic differences between the optical signals passing through the optical transmission paths.

A rare earth-doped optical fiber comprises a fluorosilicate core surrounded by a silica cladding, where the fluorosilicate core comprises an alkaline-earth fluoro-alumino-silicate glass, such as a strontium fluoro-alumino-silicate glass. The rare earth-doped optical fiber may be useful as a high-power fiber laser and/or fiber amplifier. A method of making a rare earth-doped optical fiber comprises: inserting a powder mixture comprising YbF.sub.3, SrF.sub.2, and Al.sub.2O.sub.3 into a silica tube; after inserting the powder mixture, heating the silica tube to a temperature of at least about 2000° C., some or all of the powder mixture undergoing melting; drawing the silica tube to obtain a reduced-diameter fiber; and cooling the reduced-diameter fiber. Thus, a rare earth-doped optical fiber comprising a fluorosilicate core surrounded by a silica cladding is formed.

A measurement system is provided with an array of laser diodes with one or more Bragg reflectors. At least a portion of the light generated by the array is configured to penetrate tissue comprising skin. A detection system configured to: measure a phase shift, and a time-of-flight, of at least a portion of the light from the array of laser diodes reflected from the tissue relative to the portion of the light generated by the array; generate one or more images of the tissue; detect oxy- or deoxy-hemoglobin in the tissue; non-invasively measure blood in blood vessels within or below a dermis layer within the skin; measure one or more physiological parameters based at least in part on the non-invasively measured blood; and measure a variation in the blood or physiological parameter over a period of time.

A fiber amplifier is provided, including a pump laser (202), a pump and signal combiner (203), and a few-mode doped fiber (204). The pump laser (202) is configured to output pump light. The pump and signal combiner (203) is configured to couple input few-mode signal light and the pump light into the few-mode doped fiber (204). Refractive indexes of a fiber core of the few-mode doped fiber (204) are distributed to be gradient along a radial direction of a cross section, the fiber core is etched with periodic gratings along an axial direction, and periods of the gratings satisfy a phase matching condition. The fiber amplifier achieves strong coupling and co-amplification between optical signal modes, thereby reducing a differential gain between mode groups.