Sum frequency generation of red light in QPM LiNbO/sub 3/ using a high-power Er/Yb fiber amplifier

Summary form only given. We describe a new type of coherent red light source which has the potential of low cost, high efficiency and multiwatt output powers. Red light was generated by sum frequency mixing of the outputs of a high-power Er/Yb co-doped fiber (EYDF) amplifier pumped by a 1064-nm Nd:YAG laser. The 9-m-long, single-mode EYDF copropagating amplifier had a gain peak near 1535 nm and was seeded by a laser diode. The fiber amplifier served as an efficient power converter of the 1064-nm pump light into 1.5-/spl mu/m emission. To generate sum frequency, the 1535 and 1064 nm radiation emerging from the angle-cleaved output end of the amplifier was focused directly into a nonlinear crystal using a dichroic lens. Two fiber polarization controllers were used to achieve polarization at both wavelengths, which was linear and parallel to the crystal c-axis. A 2.2-cm-long LiNbO/sub 3/ crystal was periodically poled to obtain a domain period of 11.2 /spl mu/m, calculated to produce sum frequency generation quasi-phase matching near 120/spl deg/C.