The development of high power, pulsed fiber laser systems and their applications
Due to the recent renewal in interest in fiber laser technology, continuous wave (c.w.) laser technology using rare-earth doped silica fibers has developed rapidly in the past few years. In the late 80s, Erbium Doped Fiber Amplifiers were commercialised and became widely used in the telecommunications industry. Yb-doped silica fiber is particularly attractive as its broad gain bandwidth and high optical efficiency make it a preferred choice for both pulsed and c.w. high power fiber laser and amplifier applications. With the advent of cladding pump technology, low cost, high power broad-stripe semiconductor laser diodes with multimoded radiation could be efficiently used to produce high power Yb-doped silica fiber lasers with either single (~ 1 kW) or multimode (~ 10 kW) emission. Finally, the development and demonstration of a novel gain switched laser diode operating at 1 µm is reported. Using this gain switched laser diode as a seed source; the output gain switched pulses were compressed to 20 ps using a fiber compressor and thereafter amplified to achieve an output average power of 11.1 W at 1 GHz repetition rate using an YDFA cascade. Additional novel work was carried out later where a linearly dispersive CFBG was used to compress the pulses to 16.6 ps. These pulses were later amplified to average powers of 321 W at 1 GHz. This we believe is the highest output power ever achieved for a short pulse fiber laser system.