Continuously tunable laser output at 60.4 nm in the range of 735.7 nm to 796.1 nm has been obtained in an alexandrite laser with a three-element quartz birefringent filter. The laser linewidth is about 0.001 nm when a LiF crystal as passive Q-switch is used for single pulse operation. The output energy does not decrease obviously while the oscillating threshold increases by only 5%.