A low bias stabilization method for deeply-modulated analog photonic links

In this paper, we propose and experimentally demonstrate a novel dither-free low bias stabilization method with circulators-assisted in deeply-modulated analog photonic links. The stabilization is achieved by reversely transmitting and power locking a lightwave along the Mach-Zehnder modulator (MZM). Using this technique, bias locking at a low bias position with less than ±0.3 degree phase deviations is achieved even when the input RF voltage is as high as 1.4 V_π. This low bias stabilization method is relatively simple and convenience but effective and accuracy, so that it is potentially to be applied in radio-over-fiber links.