Simultaneous cw red, yellow, and green light generation, “traffic signal lights,” by frequency doubling and sum-frequency mixing in an aperiodically poled LiTaO3

We demonstrate simultaneously efficient generation of cw red, yellow, and green coherent radiations, “traffic signal lights,” by multifrequency conversions from a diode-pumped Nd:YVO4 dual-wavelength laser with a single-pass aperiodically poled LiTaO3. The 1.8 mW red at 671 nm and 0.64 mW green at 532 nm are, respectively, generated by frequency doubling of fundamental waves at 1342 and 1064 nm, and 0.79 mW yellow at 593 nm is produced by sum-frequency mixing of the two fundamental waves, under two fundamental waves of 970 mW at 1342 nm and 940 mW at 1064 nm.