A single-longitudinal-mode sum-frequency 593.5 nm laser was developed using a Fabry-Perot etalon as the frequency selector. For a single Nd:YVO

4

crystal

stable dual-wavelength operation of 1 064 nm and 1 342 nm was obtained in a linear cavity by optimally designing the films on the output mirror of a cavity. The sum-frequency generation was realized using a type-I phase-matching LBO crystal for the sum-frequency mixing of 1 064 nm and 1 342 nm. Under the pump power of 2 W

52 mW yellow-orange light at 593.5 nm was generated with a RMS noise of 6.8%. Then a 400 μm thick fused quartz was inserted into the cavity for frequency selection

34 mW single-longitudinal-mode light with a linewidth of about 600 MHz at 593.5 nm was obtained by tuning the tilt angle of the etalon. The noise of the output light was remarkably reduced to the RMS noise of 0.3%. The results show that it is an easy and efficient way to employ a single Fabry-Perot etalon as the frequency selector to obtain single-longitudinal operation of the sum-frequency light in the process of sum-frequency generation.