Abstract

Passive self-injection locking (PSIL) laser control yields efficiency close to that in the optimized non-selective cavity [1]. The principle of PSIL lies in the spectrally selective reinjection through the one of the outputs in two-outputs cavity. Its main problem is the wideband free lasing at high pump levels. We show (theory, experiment) that die background emission in a PSIL-controlled dye or Ti:Al₂O₃ laser can be reduced drastically by dual-pulse pumping when the laser is pumped first by a near threshold pulse and second by the main pulse which is X=30+50 times the threshold. The scheme of the dual-pulse pumped PSIL-controlled two-wavelength dye laser is presented in Fig.1. The cavity is formed by the laser output mirror M₁ (R=0.9) and two interference structures - M₂ (R=0.7), IW₁ and M₃ (R=1) selects λ₁ and M₂ IW₁ as an intermediate reflector, IW₂ as a selector and M₄ (R=1) selects λ₂- The IW_1,2 are interference wedges (thickness 5µm, reflectivity of the coatings 0.9, wedge angle 3.10^-5 rad).

© 1996 IEEE