ABSTRACT
A ›ber ampli›er can be converted into a laser by placing it inside a cavity designed to provide positive optical feedback. Such lasers are called ›ber lasers. A ›ber laser is an important element in all optical ›ber communication systems, sensors, and photonic switching systems. There are a number of potential operating characteristics that make the ›ber lasers particularly attractive. The lasers have been shown to have quantum-limited noise, narrow pulse width, both active and passive MLFLs, higher repetition rate (active MLFL), transform-limited pulses, etc. Comparing with laser diodes, ›ber lasers have many advantages, such as low threshold value, high average optical power, low timing jitter, low pulse dropout ratio, wide wavelength tunable range, high ef›ciency, and compatibility with ›ber devices [1,2]. Despite the advantages of the ›ber lasers, there are also some dif›culties, such as environmental sensitivity, rare components, unpredictable pulse spacing, bistable operation, and extra spectral components. As a result, a large number of designs have been examined, attempting to optimize the laser operation to suit desired applications.
