Novel Optogalvanic Spectroscopy of Semiconductor Atoms with a Frequency-tripled ns Ti:sapphire Laser Injection-seeded by a cw Frequency-scanning Ti:sapphire Laser

Abstract

Novel optogalvanic spectroscopy of silicon atoms was conducted with the narrow-linewidth nanosecond pulsed deep-ultraviolet coherent light source which was comprised of the frequency-tripled nanosecond pulsed Ti:sapphire laser injection-seeded by another frequency-scanning cw Ti:sapphire laser. Only when the laser frequency of the seed laser matched with the cavity frequency of the slave laser, signals increased remarkably. The individual spectral widths derived from the injection-seeding effect should be the tolerance for successful injection-seeding in the axial mode of the slave laser, and indicated the linewidth of the injection-seeded ns pulsed deep-ultraviolet laser. So the cavity performances of the slave laser can be seen from the spectrum. The envelope of these peaks indicated the absorption spectrum of silicon atoms. This spectral width had the FWHM of 4.8 GHz in the Gaussian fitting and was equivalent to nearly the pure Doppler width, which could not be measured with the system without the injection seeding.