掺镱光子晶体光纤飞秒激光器噪声的测量

Measurement of the Noise of Yb-Doped Femtosecond Photonic Crystal Fiber Laser

小型化、低成本和低噪声的激光器有助于实用化非经典光源的实现。掺镱光子晶体光纤锁模激光器与钛宝石激光器相比,具有系统结构简单、体积小和价格低的优点,但其噪声特性还有待深入研究。采用一套适用于测量脉冲激光器噪声的自零拍探测系统,对掺镱光子晶体光纤飞秒激光器的噪声进行了测量分析。结果表明掺镱光子晶体光纤飞秒激光器的振幅噪声显著高于其散粒噪声基准,说明该激光器的输出不是理想的相干态光场,其噪声特性有待进一步提高。

Lasers with compact size, low cost and low noise are desirable for developing practical non-classical sources. Compared with Ti.＂ sapphire mode-locked laser, Yb-doped photonic crystal fiber （PCF） based mode-locked laser has the advantages of simple structure, compact size and low cost, but its noise characteristics need to be further investigated. The noise of an Yb-doped PCF based femtosecond laser is measured and analyzed by a homemade self-homodyne detection system which is suitable for measuring the noise of pulsed laser. The results show that the amplitude noise of the PCF based laser is much higher than that of the shot noise level, which means that the output of the laser is not in the ideal coherent state, and its noise characteristics should be further imnroved.