Biedermann Benjamin R, Wieser Wolfgang, Eigenwillig Christoph M, Klein Thomas, Huber Robert
Lehrstuhl für BioMolekulare Optik, Fakultät für Physik, Ludwig-Maximilians-Universität München, Munich, Germany.
Opt Express. 2009 Jun 8;17(12):9947-61. doi: 10.1364/oe.17.009947.
We report on the effect of chromatic dispersion on coherence length and noise of Fourier Domain Mode Locked (FDML) lasers. An FDML laser with a sweep range of 100 nm around 1550 nm has been investigated. Cavity configurations with and without dispersion compensation have been analyzed using different widths of the intra-cavity optical band-pass filter. The measurements are compared to non-FDML wavelength swept laser sources. Based on these observations, a simple model is developed providing a connection between timing, photon cavity lifetime and characteristic time constant of the filter. In an optimized configuration, an instantaneous laser linewidth of 20 pm is observed, corresponding to a 10x narrowing compared to the intra-cavity optical bandpass filter. A relative intensity noise of -133 dBc/Hz or 0.2% at 100 MHz detection bandwidth during sweep operation is observed. For optimum operation, the filter drive frequency has to be set within 2 ppm or 120 mHz at 51 kHz.
我们报告了色散对傅里叶域锁模（FDML）激光器的相干长度和噪声的影响。研究了一种在1550nm附近具有100nm扫描范围的FDML激光器。使用不同宽度的腔内光学带通滤波器，分析了有无色散补偿的腔配置。将测量结果与非FDML波长扫描激光源进行比较。基于这些观察结果，建立了一个简单的模型，该模型提供了时间、光子腔寿命和滤波器特征时间常数之间的联系。在优化配置中，观察到瞬时激光线宽为20pm，与腔内光学带通滤波器相比，窄了10倍。在扫描操作期间，在100MHz检测带宽下观察到相对强度噪声为-133dBc/Hz或0.2%。为实现最佳操作，滤波器驱动频率必须设置在51kHz时的2ppm或120mHz范围内。
