All-fiber high-energy yb-doped fiber amplifier

We report a robust, all-fiber amplifier seeded by a fiber oscillator. Seed pulses at 1 MHz repetition rate are amplified up to 3 μJ, delivering 1 μJ-energy, 170 fs-long pulses. Duration reduces to 120 fs at 1 μJ amplifier output. These are the highest peak powers from an integrated fiber source. © 2009 IEEE

Fiber amplification of pulse bursts at low repetition rates via synchronous pulsed pumping

We report, for the first time, amplification of pulse-bursts in Yb-doped fiber at repetition rates as low as 200 Hz for applications to accelerators and material processing. Synchronous pulsed pumping allows suppression of ASE generation. © 2011 Optical Society of America

Burst-mode Yb fiber amplifier producing 30 μJ individual pulse energy

We report 30-μJ individual pulse energy for 150-ns long amplified bursts of 0.4 mJ total energy from a 1-kHz Yb-fiber amplifier. Non-uniformity of pulse energy distribution inside amplified bursts is significantly reduced. ©2012 Optical Society of America

Fluence of thulium laser system in skin ablation

Tm:YAP laser system at power levels up to 1.2 W at 1980 nm was established in both continuous-wave and modulated modes of operation. The fluence effect of the laser system for skin ablation was analyzed by histology analysis with Wistar rat skin tissues. Thermally altered length, thermally altered area, ablation area, and ablation depth parameters were measured on histology images of skin samples just after the laser operation and after four-day healing period. Continuous-wave mode of operation provided higher thermal effects on the skin samples. Lower fluence levels were found for efficient ablation effect. © 2010 IEEE

Doping management for high-power fiber lasers: 100 W, few-picosecond pulse generation from an all-fiber-integrated amplifier

Thermal effects, which limit the average power, can be minimized by using low-doped, longer gain fibers, whereas the presence of nonlinear effects requires use of high-doped, shorter fibers to maximize the peak power. We propose the use of varying doping levels along the gain fiber to circumvent these opposing requirements. By analogy to dispersion management and nonlinearity management, we refer to this scheme as doping management. As a practical first implementation, we report on the development of a fiber laser-amplifier system, the last stage of which has a hybrid gain fiber composed of high-doped and low-doped Yb fibers. The amplifier generates 100 W at 100 MHz with pulse energy of 1 μJ. The seed source is a passively mode-locked fiber oscillator operating in the all-normaldispersion regime. The amplifier comprises three stages, which are all-fiber-integrated, delivering 13 ps pulses at full power. By optionally placing a grating compressor after the first stage amplifier, chirp of the seed pulses can be controlled, which allows an extra degree of freedom in the interplay between dispersion and self-phase modulation. This way, the laser delivers 4.5 ps pulses with ∼200 kW peak power directly from fiber, without using external pulse compression. © 2012 Optical Society of America

Microjoule pulse energies at 1 MHz repetition rate from an all-fiber nonlinear chirped-pulse amplifier

We report a 1-MHz robust, all-fiber amplifier-oscillator system. Amplified pulses of 3 μJ are externally compressed to 140 fs. The highest peak power from an integrated fiber source, up to 50 kW, is obtained. © 2010 Optical Society of America