Active mode locking in an yttrium erbium aluminum garnet crystal laser (λ = 2.94μ)

A constant-temperature yttrium erbium aluminum garnet crystal laser was actively mode locked by resonant modulation of the resonator losses using a lithium niobate electrooptic modulator with Brewster faces without any polarizers. This gave a modulation depth 2.6 times greater than that for a modulator with an ideal polarizer. A spike energy of ~1 mJ was obtained with an estimated duration of 200 psec in the 1.7 mm diameter TEM₀₀ mode. The laser radiation was elliptically polarized. It was found that three-micron radiation could be recorded using an SNF-T photomultiplier.