Abstract: An apparatus for generating short optical pulses is provided having a storage medium capable of storing optical energy, a first module for delivering pumping optical pulses or continuous beam into the storage medium to energize the storage medium, and a second module for delivering one or more trigger optical pulses to the optical storage medium. Each of the trigger optical pulses has a rising edge which causes a cascade release of the energy stored in the storage medium in an output optical pulse having a greater power and narrower in width or duration (at full width at half maximum) than the trigger optical pulse that caused the output pulse. A control module in the apparatus controls the operation of the pump module and trigger module so as to provide the desired characteristics of output optical pulses from the apparatus.

Abstract: An apparatus for generating short optical pulses is provided having a storage medium capable of storing optical energy, a first module for delivering pumping optical pulses or continuous beam into the storage medium to energize the storage medium, and a second module for delivering one or more trigger optical pulses to the optical storage medium. Each of the trigger optical pulses has a rising edge which causes a cascade release of the energy stored in the storage medium in an output optical pulse having a greater power and narrower in width or duration (at full width at half maximum) than the trigger optical pulse that caused the output pulse. A control module in the apparatus controls the operation of the pump module and trigger module so as to provide the desired characteristics of output optical pulses from the apparatus.

Abstract: An apparatus for generating short optical pulses is provided having a storage medium capable of storing optical energy, a first module for delivering pumping optical pulses or continuous beam into the storage medium to energize the storage medium, and a second module for delivering one or more trigger optical pulses to the optical storage medium. Each of the trigger optical pulses has a rising edge which causes a cascade release of the energy stored in the storage medium in an output optical pulse having a greater power and narrower in width or duration (at full width at half maximum) than the trigger optical pulse that caused the output pulse. A control module in the apparatus controls the operation of the pump module and trigger module so as to provide the desired characteristics of output optical pulses from the apparatus.

Abstract: The disclosed fiber Raman device comprises means for coupling pump radiation of a first wavelength &lgr;1 and a second wavelength &lgr;2 into a length of silica-based fiber, with &lgr;1 being different from &lgr;2, and with both of &lgr;1 and &lgr;2 being less than an output radiation &lgr;0 of the fiber Raman device. The Raman device further comprises at least a first and a second wavelength-selective element disposed to provide one or more optical cavities for Raman shifting of light in the fiber. At least one of the optical cavities is selected such that at least one of &lgr;1 and &lgr;2 is off resonance. Exemplarily, the Raman device is a topologically linear or circular Raman laser or amplifier, and the wavelength selective element is a fiber Bragg grating or a WDM. The Raman device is advantageously used in an optical fiber communication system.

Abstract: An optical isolator which is suitable for array assembly and may be produced by lithographically-defined means comprises a sandwich of layers. These layers include a substrate having two waveguides for transmission of a signal having two parts, each part being comprised of two rays; a walk-off plate for spatially displacing or recombining the rays of both parts; a half-wave plate of birefringent material for reciprocal rotation of the polarization of the rays of only one part of the signal; a non-reciprocal rotator for rotating the polarization of the rays of both parts of the signal at a predetermined angle; a lens for collimating the rays transmitted through the walk-off plate, the half-wave plate, and the rotator, and for focusing the rays opposite the rotator at a common region along an end surface; and an end surface for interconnection of the rays of the two parts of the signal.

Abstract: A heater system for heating an erbium-doped fiber amplifier (EDFA) of a fiber optic communication system operable in an environment. The heater system includes a pump laser for providing optical power to an erbium fiber in the EDFA. The pump laser is cooled by a thermoelectric cooler (TEC) when a predetermined maximum temperature is reached to maintain the temperature of the laser below the maximum temperature value. The temperature of the laser is sensed by a temperature sensor and is conveyed to a control circuit for generating a control signal. A heater unit is thermally connected to the erbium fiber and is controlled by the control signal in the event that the sensed temperature falls below a predetermined minimum value to maintain the temperature of the fiber above the minimum temperature value. A switch is connected between the control circuit, the TEC and the heater to automatically direct current to either the heater or the TEC depending on the sensed temperature.

Abstract: An optical multiplexer is formed that overcomes the polarization dependence of conventional DWDM routers and is also significantly smaller than prior art routers. A reflective router is formed that utilizes one-half of a star coupler, with a reflective surface formed along the planar face of the coupler so as to form a "folded" arrangement. First and second waveguide arrays are coupled to opposing quadrants of the folded coupler, with the reflective surface providing the coupling therebetween. A quarter wave plate (or Faraday rotator) and reflective surface are disposed at the output of the second waveguide array and are used to provide a TE/TM mode conversion to the optical signals exiting the second array (thereby canceling out any polarization-dependent effects). The reflective surface beyond the quarter wave plate re-directs the optical signal back through the second waveguide array. The signal will then again reflect through the folded coupler and exit the multiplexer through the first waveguide array.

Abstract: In an optical fiber light source a section of multimode fiber is interposed between an energizing laser (e.g,, a diode laser) and a single mode fiber active medium. In a preferred embodiment the single mode fiber active medium is surrounded by a multimode cladding coupled to the multimode fiber. The source may serve as a pump laser for a fiber amplifier or as an amplified spontaneous emission source. Arrangements for coupling several energizing lasers to the active medium are also described.