Noise characteristic of sum-frequency mixing orange solid-state laser

A laser-diode-pumped Nd:YVO₄ orange solid-state laser is described in this paper. The fundamental wavelengths at 1064 and 1342 nm oscillate simultaneously and generate the 593.5 nm wavelength by intracavity sum-frequency mixing in a KTP crystal using type II phase matching. The noise characteristic of laser output has been measured and analyzed at different pumping powers. The relationship between the amplitude noise of sum-frequency mixing output and the longitudinal modes of fundamental frequency has been investigated. The results show that the sum-frequency mixing output has low noise if one of the fundamental wavelengths is single longitudinal mode. The experiment shows that amplitude noise of the intracavity sum-frequency mixing laser is lower than that of intracavity frequency doubled laser with the same structure.