Passively Q-switched laser based on Nd:YAG/YAG Polygonal Active Mirror with timing jitter improvement

We demonstrate a passively Q-switched laser based on Polygonal Active Mirror (PAM). Cr:YAG with different initial transmittance were used as saturable absorber (SA). To improve the output timing jitter, an intracavity aperture was used. Without the intracavity aperture, the maximum average output power of 726 mW was obtained with SA initial transmittance of 98%, and the corresponding optical-to-optical efficiency was 23.3%. With 92% initial transmittance SA, the maximum slope efficiency of 49.9% was obtained, and the maximum single pulse energy was 132.8 uJ. By applying the intracavity aperture, the output beam quality and timing jitter were improved. With 98% initial transmittance Cr:YAG SA, the beam quality (M2) was improved from 1.40×1.22 to 1.33×1.19 after applying the aperture, while timing jitter was improved from 18.4μs(31.68%) to 4.8μs(8.61%).