FM and AM mode locking of the homogeneous laser - Part II: Experimental results in a Nd:YAG laser with internal FM modulation

In Part I of this paper [1], a theoretical analysis of the mode-locked homogeneous laser was given. In this part we present experimental results for the Nd:YAG laser with internal phase modulation. LiNbO3was used as the modulator crystal, and a method to measure the single-pass phase retardation of the modulator accurately at 1.06 μ is described in detail. The pulsewidth and spectral width of the mode-locked laser were measured as a function of depth of modulation, and good agreement with theory was obtained. Etalon effects in the laser were observed, and the results agreed very well with the theory. Mode-locked spectral bandwidths of up to 16 GHz, implying mode-locked pulses as short as 40 ps, were obtained.