EXTREMELY STABLE, SPECTRALLY NARROW, HIGH REPETITION RATE RATE DYE LASER SYSTEM

THE FEASIBILITY OF DEVELOPING AN EXTREME STABLE, SPECTRALLY NARROW (150 MEZ), HIGH REPETITION RATE (30 KHZ) TUNABLE DYE LASER OSCILLATING IN A SINGLE LONGITUDINAL MODE OVER THE ENTIRE RANGE OF THE DYE IS EXAMINED. THE EXTREME SHORT CAVITY (5 CM), LONGITUDINAL PUMPED GRAZING INCIDENCE DYE LASER DESIGN OF THE PROPOSED SCHEME PROVIDES MANY DISTINCT ADVANTAGES. THE SHORT CAVITY DESIGN NOT ONLY SUPPORTS MULTIPLE CAVITY ROUND TRIPS THROUGH A HOMOGENEOUSLY BROADENED LASER MEDIUM DURING THE SHORT INVERSION TIME BUT ALSO MAKES THE SPACING BETWEEN ADJANCENT LONGITUDINAL MODES VERY LARGE. THIS RESULTS IN AN EXTREME REDUCTION OF THE AMPLIFIED SPONTANEOUS EMISSION, SINGLE MODE OPERATION OF THESYSTEM AND GREAT STABILITY IN THE FREQUENCY OUTPUT. THE GRAZING INCIDENCE DESIGN OF THE GRATING ELIMINATES THE NEED OF INTERACAVITY BEAM EXPANDING OPTICS, YET PROVING HIGH RESOLUTION AND SPECTRALLY NARROW LINEWIDTH (150 MHZ) OVER THE ENTIRE TUNING RANGE OF THE DYE. THE MINIMUM NUMBER OF OPTICAL ELEMENTS USED NOT ONLY REDUCES THE UNDESIRABLE REFLECTION LOSSES BUT ALSO MAKES THE UNIT LESS SENSITIVE TO TEMPERATURE CHANGE, LESS VULNERABLE TO HIGH POWER BEAM, AND EXTREMELY EASY TO ALIGN. MOREOVER, USING THE MIRROR (NOT THE GRATING) AS A TUNING ELEMENT, ENSURES THAT THE MODE NUMBER AND LINEWIDTH ARE PRECISELY PRESERVED DURING THE SCANNING PROCESS.