Development of a Tunable Ultrashort Dye Laser System by Using Molecular Photonic Processes and a Nanosecond Pumping Laser

Abstract

The paper presents the physical processes and operational characteristics of an original subpicosecond dye laser system which is designed and successfully developed at our laboratory basing on the combination use of three photonic processes of dye molecules: 1) Fast spectrotemporal evolutions in the broadband dye laser emissions; 2) Generation of a chain of ultrashort pulses (spikes) from low-Q micro-cavity dye lasers; and 3) Non-linear resonant interaction between ultrashort laser pulses and highly-saturated dye media. Such a laser system provides a stable generation of single 500 fs pulses with a peak power of 300 MW at 606 nm. Particularly, the whole sub-picosecond laser system is pumped by a single nanosecond laser (Q-switched Nd:YAG laser). The spectral and time processes involved in these pulse-shortening methods are analyzed with a rate-equation model extended to wavelengths. A white light continuum generation was obtained by focusing the 500 fs pulses into 2 cm water cell. As a result, it enables us to produce widely tunable ultrashort laser pulses with a spectral selection and amplification of the supercontinuum spectrum.