Department of Electrical Engineering-Electrophysics, University of Southern California, Los Angeles, California 90089, USA.
Opt Lett. 2012 Jan 15;37(2):196-8. doi: 10.1364/OL.37.000196.
A wideband laser phase noise reduction scheme is introduced where the optical field of a laser is single sideband modulated with an electrical signal containing the discriminated phase noise of the laser. The proof-of-concept experiments on a commercially available 1549 nm distributed feedback laser show linewidth reduction from 7.5 MHz to 1.8 kHz without using large optical cavity resonators. This feed-forward scheme performs wideband phase noise cancellation independent of the light source and, as such, it is compatible with the original laser source tunability without requiring tunable optical components. By placing the proposed phase noise reduction system after a commercial tunable laser, a tunable coherent light source with kilohertz linewidth over a tuning range of 1530-1570 nm is demonstrated.
介绍了一种用于降低激光相位噪声的宽带方案，该方案通过单边带调制激光光场，利用包含激光鉴相相位噪声的电信号对其进行调制。基于商用的 1549nm 分布反馈激光器进行的原理性实验表明，无需使用大的光腔谐振器，即可将线宽从 7.5MHz 降低至 1.8kHz。该前馈方案可独立于光源实现宽带相位噪声消除，因此与原始激光源的可调谐性兼容，无需使用可调谐光学元件。通过在商用可调谐激光器之后放置所提出的相位噪声降低系统，展示了一种在 1530nm 到 1570nm 的调谐范围内具有千赫兹线宽的可调谐相干光源。
