Abstract: The invention provides a self-modulating input electrical power laser control system and method. After the laser is turned on for a period of time, the control module reduces the initial electrical power to the operating power of the laser, and it maintains the operating power until the laser is turned off, which can reduce the extra power consumption and achieve the energy-efficiency.

Abstract: A modal instability of a fiber amplifier may be reduced by coupling, e.g. splicing, a length of passive multimode optical fiber to an active multimode optical fiber of the fiber amplifier. Upon launching light into the passive optical fiber, some higher order transversal modes may be excited in the passive optical fiber. The higher-order modes may interfere with the fundamental mode in the passive multimode optical fiber. However, the intermodal interference of the launched modes does not cause thermal gradients in the passive optical fiber. Upon propagation in the passive multimode optical fiber, the excited optical modes may lose mutual coherence, causing a reduction of contrast of the intermodal interference pattern along the doped core of the active optical fiber, effectively reducing modal instability in the active optical fiber.

Abstract: A modal instability of a fiber amplifier may be reduced by coupling, e.g. splicing, a length of passive multimode optical fiber to an active multimode optical fiber of the fiber amplifier. Upon launching light into the passive optical fiber, some higher order transversal modes may be excited in the passive optical fiber. The higher-order modes may interfere with the fundamental mode in the passive multimode optical fiber. However, the intermodal interference of the launched modes does not cause thermal gradients in the passive optical fiber. Upon propagation in the passive multimode optical fiber, the excited optical modes may lose mutual coherence, causing a reduction of contrast of the intermodal interference pattern along the doped core of the active optical fiber, effectively reducing modal instability in the active optical fiber.

Abstract: An optical power monitoring device includes a photodetector disposed in close proximity to the cladding of an optical fiber for measuring Rayleigh scattered light from the core of the optical fiber. To ensure only Rayleigh scattered light is measured, a cladding stripper is provided to remove any cladding light prior taking a reading with the photodetector.

Abstract: An optical power monitoring device includes a photodetector disposed in close proximity to the cladding of an optical fiber for measuring Rayleigh scattered light from the core of the optical fiber. To ensure only Rayleigh scattered light is measured, a cladding stripper is provided to remove any cladding light prior taking a reading with the photodetector.

Abstract: High efficiency reflective volume Bragg gratings with chirped gratings recorded in photo-thermo-refractive glass having an absolute diffraction efficiency exceeding 95% in transmitting and reflecting modes are used to stretch and/or compress ultrashort laser pulses with high efficiency. Robustness, compactness, thermal and laser stability along with placement of multiple elements in the same space provides femtosecond laser system with high efficiency of stretching and re-compression of femtosecond pulses.

Abstract: High efficiency reflective volume Bragg gratings with chirped gratings recorded in photo-thermo-refractive glass having an absolute diffraction efficiency exceeding 95% in transmitting and reflecting modes are used to stretch and/or compress ultrashort laser pulses with high efficiency. Robustness, compactness, thermal and laser stability along with placement of multiple elements in the same space provides femtosecond laser system with high efficiency of stretching and re-compression of femtosecond pulses.