基于色散波的1μm飞秒光纤啁啾脉冲放大系统

1μm Femtosecond Fiber Chirped Pulse Amplification System Based on Dispersion Wave

飞秒激光在工业加工、激光传感、军事国防、科学研究等领域有着重要的应用前景。报道了一个工作在1μm波段的飞秒光纤啁啾脉冲放大(FCPA)系统。该系统主要包括一个1.5μm全光纤被动锁模光源、一个1μm波段非线性频率转换装置、两级掺镱光纤放大器及一个基于透射式衍射光栅对的脉冲压缩器。掺铒锁模光源中心波长为1.55μm、3dB光谱带宽为12.9nm、重复频率为17.5MHz,经功率放大后注入一段9.5cm高非线性光纤中产生1μm波段色散波,其中心波长为1070nm,3dB光谱带宽为33nm。将此色散波脉冲作为种子源通过声光调制器选频后得到重复频率为1.09 MHz的脉冲输出。随后功率放大至11.4 W,压缩后得到平均功率为7.7 W、10dB光谱宽度为21.4nm、脉冲宽度为270fs、峰值功率为26 MW的飞秒脉冲激光输出。

Femtosecond laser has important applications in such fields as industrial processing, laser sensing, military defense, and scientific research. A femtosecond fiber chirped pulse amplification （FCPA） system operating at 1 μm is reported. This system consists of a 1.5 μm all-fiber passive mode-locked laser source, a 1 μm nonlinear frequency converter, a two-stage Yb-doped amplifier, and a transmission diffraction grating pulse compressor. The center wavelength of the erbium-doped mode light source is 1.55 μm, the spectral bandwidth of 3 dB is 12.9 nm and the repetition frequency is 17.5 MHz. After power amplification, a 9.5 cm high nonlinear fiber is injected to generate 1 μm band dispersion wave with center wavelength of 1070 nm and 3 dB spectral bandwidth of 33 nm. Moreover, using this dispersion wave pulse as the seed source, the pulse output with repetition rate of 1.09 MHz is achieved by using a frequency selector of acousto-optic modulator. After that, the power is amplified to 11.4 W, and with the femtosecond pulse laser output with average power of 7.7 W, spectral bandwidth of 21.4 nm at 10 dB, pulse duration of 270 fs, and peak power of 26 MW is achieved after compression.