FEMTOSECOND PULSES FROM THE ULTRAVIOLET TO THE INFRARED - OPTICAL PARAMETRIC PROCESSES IN A NEW LIGHT

Authors
Citation
Hm. Vandriel et G. Mak, FEMTOSECOND PULSES FROM THE ULTRAVIOLET TO THE INFRARED - OPTICAL PARAMETRIC PROCESSES IN A NEW LIGHT, Canadian journal of physics, 71(1-2), 1993, pp. 47-58
Citations number
70
Categorie Soggetti
Physics
Journal title
ISSN journal
00084204
Volume
71
Issue
1-2
Year of publication
1993
Pages
47 - 58
Database
ISI
SICI code
0008-4204(1993)71:1-2<47:FPFTUT>2.0.ZU;2-F
Abstract
Although the optical parametric oscillator (OPO) is more than 25 years old, it has not seen widespread use unlike other tunable sources such as the dye laser. Part of the reason for this is the low-gain - high- threshold associated with the weak conversion mechanism in the nonline ar optical crystals. Pump lasers with high peak intensities are usuall y required, which, unfortunately, run the risk of damaging the crystal s, especially if their pulse duration is nanoseconds or picoseconds. R ecently, however, the emergence of new, more efficient, nonlinear crys tals and the development of continuously mode-locked, solid-state lase rs, such as the Kerr-lens mode-locked Ti:sapphire laser, has led to a renaissance for OPOs. For example, the Ti:sapphire laser with an avera ge power of over 1 W, with pulses less-than-or-equal-to 100 fs long at a 100 MHz repetition rate, has allowed us to construct a stable, low- noise, synchronously pumped OPO. The output pulses are as short as 60 fs and can be produced in the wavelength range from 1 to 4 mum with av erage power as high as 200 mW. Harmonic generation of the OPO or the T i:sapphire laser beams provides wavelength coverage from 200 nm to 4 m um. Through difference-frequency-mixing of the two output beams of the OPO in chalcopyrite or proustite crystals we anticipate being able to generate femtosecond pulses at wavelengths from 200 nm to beyond 20 m um. This broad-band, stable light source will open up new areas of inv estigation in physics, chemistry, and engineering.