A two-wavelength, passively self-injection locked, CW Ti/sup 3+/:Al/sub 2/O/sub 3/ laser

We have demonstrated that passive self-injection control is very effective in a CW Ti/sup 3+/:Al/sub 2/O/sub 3/ laser to produce high efficiency (/spl eta//spl sim/15%), narrow-line, two-wavelength emission. Light reinjection is achieved with an original high-resolution two-wavelength selector combining an interference wedge and a grazing incidence grating. The device operates outside the main nonselective laser cavity; thus avoiding insertion losses and optical damage problems. A 1.5 W, background free, total output power has been obtained simultaneously at two narrow laser lines (fwhm: 8 pm), independently tunable over 50 mn. The two laser lines can be emitted in a single beam or in two separated beams. Self-injection wavelength control has been demonstrated both for linear and for ring laser cavities. In the latter case, unidirectional behavior is also obtained in the same way. Single-step (5s/sup 2/S/sub 1/2/-5P/sup 2/P/sub 1/2,3/2/) and two-step (5s/sup 2/S/sub 1/2/-5p/sup 2/P/sub 3/2/-5d/sup 2/D/sub 3/2,5/2/) excitation of atomic rubidium vapor has been performed with our original laser device.>