Abstract: A laser system is configured with at least one light amplifying device sequentially outputting a light signal at first and at least one additional operating wavelengths over respective time intervals. Each time interval is shorter than the predetermined lifespan of the light amplifying device. The total useful life of the light amplifying device, operating at a plurality of wavelengths, is 3-10 times longer than the predetermined lifespan.

Abstract: A laser system and method. In one example, the laser system includes an optical pulse stretcher configured to stretch pulse durations of an input train of input pulses to produce a train of stretched laser pulses, a pulse replicator module configured to increase a pulse repetition rate of the train of stretched laser pulses to produce a modified pulse train of laser light, a fiber power amplifier configured to amplify the modified pulse train to produce amplified laser pulses, and a pulse compressor that temporally compresses the amplified laser pulses to produce amplified and compressed laser pulses. The system may further include a nonlinear frequency conversion stage comprising at least one nonlinear crystal.

Abstract: In a particular embodiment, a relatively high-energy thulium fiber laser operating at the wavelength ?=2 ?m may be used to selectively modify a front and/or a back surface of silicon and gallium arsenide wafers. The processing regime was studied in terms of the process parameters variation, and the corresponding modification fluence thresholds were determined. The results revealed considerable differences in morphology between front and back surface modifications, and that the back surface modification threshold of Si is significantly higher than at the front surface. Basic analytic modeling and z-scan measurements were performed to study the absorption mechanisms. In a broader embodiment the processing regime is not specifically limited to a thulium fiber laser.