Mid-infrared Continuous-wave Optical Parametric Oscillator with a Fan-out Grating MgO:PPLN Operating Up to 5.3 μm
- Resource Type
- Academic Journal
- Authors
- In-Ho Bae; Jae-Keun Yoo; Sun Do Lim; Seung Kwan Kim; Dong-Hoon Lee
- Source
- Current Optics and Photonics. 2019-12 3(6):577-582
- Subject
- Optical parametric oscillator
Mid-infrared laser
PPLN crystals
- Language
- Korean
- ISSN
- 2508-7266
2508-7274
We report on a continuous-wave (cw) optical parametric oscillator (OPO) optimized for mid-infrared emission above 5.0 μm. The OPO is based on a magnesium-oxide-doped periodically poled LiNbO₃ (MgO:PPLN) crystal with a fan-out grating design. A linear two-mirror cavity resonating both at the pump and signal wavelengths is stabilized to the pump laser by using the modified Pound-Drever-Hall (PDH) method. The idler wavelength is continuously tunable from 4.7 μm up to 5.3 μm by varying the poling period of the fan-out grating crystal. Pumped by a diode-pumped solid state (DPSS) laser with a power of 1.1 W at 1064 nm, the maximum idler output power is measured to be 5.3 mW at 4.8 μm. The output power above 5.0 μm is reduced to the hundreds of μW level due to increased absorption in the crystal, but is stable and strong enough to be measured with a conventional detector.