ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels, Barcelona, Spain.
Opt Lett. 2011 Aug 15;36(16):3236-8. doi: 10.1364/OL.36.003236.
We report a compact, efficient, high-energy, and high-repetition-rate mid-IR picosecond optical parametric oscillator (OPO) based on the new nonlinear material CdSiP(2) (CSP). The OPO is synchronously pumped by a master oscillator power amplifier system at 1064.1 nm, providing 1 μs long macropulses constituting 8.6 ps micropulses at 450 MHz, and it can be tuned over 486 nm across 6091-6577 nm, covering the technologically important wavelength range for surgical applications. Using a compact (∼30 cm) cavity and improved, high-quality nonlinear crystal, idler macropulse energy as high as 1.5 mJ has been obtained at 6275 nm at a photon conversion efficiency of 29.5%, with >1.2 mJ over more than 68% of the tuning range, for an input macropulse energy of 30 mJ. Both the signal and idler beams are recorded to have good beam quality with a Gaussian spatial profile, and the extracted signal pulses are measured to have durations of 10.6 ps. Further, from the experimentally measured transmission data at 1064 nm, we have estimated the two-photon absorption coefficient of CSP to be β=2.4 cm/GW, with a corresponding energy bandgap, E(g)=2.08 eV.
我们报告了一种基于新型非线性材料 CdSiP(2) (CSP) 的紧凑型、高效率、高能量和高重复率中红外皮秒光参量振荡器 (OPO)。该 OPO 由 1064.1nm 的主振荡器功率放大器系统同步泵浦，提供 1μs 长的宏观脉冲，构成 450MHz 的 8.6ps 微脉冲，可在 6091-6577nm 范围内调谐 486nm，覆盖了手术应用的重要技术波长范围。使用紧凑型（约 30cm）腔和改进的高质量非线性晶体，在 6275nm 处获得了高达 1.5mJ 的闲频光宏观脉冲能量，在超过 68%的调谐范围内，光子转换效率为 29.5%，输入宏观脉冲能量为 30mJ。信号和闲频光束都记录到具有良好的高斯空间分布的光束质量，并且提取的信号脉冲的持续时间为 10.6ps。此外，根据 1064nm 处的实验测量传输数据，我们估计了 CSP 的双光子吸收系数为 β=2.4cm/GW，相应的能带隙为 E(g)=2.08eV。
