Widely phase-matched tunable difference-frequency generation in periodically poled LiNbO3 crystal

✍ Scribed by L.H. Deng; X.M. Gao; Z.S. Cao; W.D. Chen; Y.Q. Yuan; W.J. Zhang; Z.B. Gong

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 311 KB
• Volume: 281
• Category: Article
• ISSN: 0030-4018
• DOI: 10.1016/j.optcom.2007.11.058

✦ Synopsis

We report on the development of a laser source in the mid-infrared spectral region based on difference-frequency generation (DFG) in a periodically poled LiNbO 3 (PPLN) crystal. Continuously tunable coherent radiation from 2.75 to 4.78 lm was produced by optical parametric interaction between a diode-pumped monolithic continuous-wave (CW) Nd:YAG laser operating at 1.064 lm and a CW Ti:Sapphire laser tunable from 767 to 871 nm. Temperature-dependent quasi-phase-matched DFG wavelength acceptance bandwidth was studied and characterized. An empiric formula is given to estimate the phase-matched wavelength acceptance bandwidth as a function of the crystal temperature at K = 22.5 lm. A large frequency scan of 128 cm À1 (about 78 cm À1 above 1 lW) near 4.2 lm was achieved. The whole absorption spectrum of the P and R branches of the m 3 band of atmospheric carbon dioxide has been recorded with a single phase-matched frequency scan.