高功率,红光至中红外可调谐腔内和频光学参量振荡器

本文利用高重复频率,高平均功率大模场面积飞秒光纤激光器作为同步抽运源,抽运以多周期极化掺氧化镁铌酸锂为非线性晶体的单共振光学参量振荡器,获得了高功率可调谐红光至中红外光,信号光调谐范围为1450—2200 nm,闲频光调谐范围为2250—4000 nm,在2 W的抽运功率下,信号光输出波长为1502 nm时获得最大输出功率374 mW,转换效率为18.7%,脉冲宽度为144 fs,此时中红外输出中心波长为3.4μm,平均功率为166 mW.再利用BBO晶体对信号光进行腔内和频,获得和频光输出波长调谐范围为610—668 nm,在4.1 W抽运的情况下,最高平均功率为615 nm处的694 mW,转换效率达16.9%.

High power red to mid-infrared laser source from intracavity sum frequency optical parametric oscillator pumped by femtosecond fiber laser

A femtosecond laser source tuned from red to mid-infrared is demonstrated. It is based on intracavity sum frequency generation of a MgO-doped periodically poled LiNbO₃ optical parametric oscillator synchronously pumped by mode-locked Yb large-mode-area photonic crystal fiber, which has high average power and high repetition rate. The optical parametric oscillator has a wide spectral tuning range from 1450–2200 nm (for the signal) and 2250–4000 nm (for the idler) while the wavelength of the pump is 1040 nm. In the experiment, the output power of 374 mW at 1502 nm is achieved when the pump power is 2 W and the slope efficiency is 18.7%. In addition, 166 mW idler at 3.4 μm are achieved. By using a β-BaB₂O₄ for intracavity sum frequency generation, the femtosecond pulse over 610–668 nm is obtained. A 694 mW average output power of sum frequency generation is achieved for 4.1 W pump, representing 16.9% conversion efficiency at 615 nm.
Keywords： optical parametric oscillator fiber laser mid-infrared intracavity sum frequency generation