MULTIPLICATION OF SPECTRAL-LINES GENERATED BY 2-COLOR STIMULATED RAMAN EFFECT

A dye laser emitting at four different frequencies separated by 293.5 (=587/2) cm(-1) is made by inserting an etalon in the resonator cavity of the laser. This laser beam is focused into molecular hydrogen (rot ational Raman shift frequency, 587 cm(-1)) to generate a multicolor la ser beam consisting of more than 10 rotational lines in the vicinity o f the fundamental lines by four-wave Raman mixing. Such rotational lin es also occur in the vicinity of the vibrational Raman lines. Thus mor e than 25 emission lines appear simultaneously. This approach is usefu l to multiply the line density, i.e., the emission lines within a spec ified wavelength region.