Picosecond optical pulses have many scientific and instrumentation applications, such as lifetime measurements in chemistry, biology, and physics, optical probing of integrated circuits, testing of photodiodes and optoelectronic components, optical time domain reflectometry, etc. Currently, Q-switched lasers are limited by their energy storage (upper-state lifetime) to sub-Megahertz repetition rates and pulse widths on the order of a nanosecond. Mode-locked lasers generate picosecond and femtosecond pulses, but are normally limited to pulse rates above approximately 75 MHz because their cavity length becomes prohibitively long (greater than 2 meters) for lower pulse repetition rates. We propose to develop integrated fiber lasers with repetition rates in the range of 1- to 100-MHz for instrumentation and measurement applications, which benefit from these intermediate-range pulse rates. Such a laser would be very compact and require no user adjustments to optimize performance. Diodepumping of the laser provides high efficiency and long operating lifetime. By changing the length of the fiber cavity and the repetition rate to the modulator, the repetition rate could be easily changed. Adding a fiber amplifier at the output easily allows for higher average power where required. Solition pulse-shaping effects could be used to generate enhanced monomers. In Phase II, X(2) FLC polymers will be synthesized, characterized, and incorporated into a frequency doubling device containing a near-infrared diode laser or other device identified during Phase I.
