A 1064- and 1074-nm Dual-Wavelength Nd:YAG Laser Using a Fabry–Perot Band-pass Filter as Output Mirror

We propose and demonstrate a 1064- and 1074-nm dual-wavelength Nd:YAG laser by exploiting a dielectric Fabry-Perot bandpass filter (FPF) as laser output mirror. A fiber-pigtailed 808-nm laser diode array is used to pump an <;111>-cut Nd:YAG crystal with a plano-plano resonator cavity. The dielectric FPF as output mirror is specially designed to balance the net gain of 1064 and 1074 nm to obtain a dual-wavelength laser. Simultaneous dual-wavelength lasing at 1064 and 1074 nm is successfully achieved. The maximum output power of the laser is 581 mW, and the slope conversion efficiency is 18.8% with the threshold pump power of 2.1 W. The design of the FPF used as output mirror, including the relationship between FWHM and spectral separation, peak wavelength location, and peak transmission, are discussed. Compared with the coupled-cavity, etalon, or specially coated mirror methods, the FPF method presented in this paper is both easy in the selection of oscillating wavelength and simple in design and fabrication.