Precise in-band OSNR and spectrum monitoring using high-resolution swept coherent detection

Abstract

We propose and demonstrate a novel in-band optical signal-to-noise-ratio (OSNR) and spectrum monitoring technique based on swept coherent detection. This technique measures the signal and the in-band amplified spontaneous emission spectra by properly adjusting the polarization states of the signal and the local oscillator. A high resolution of 0.002 nm is achieved. By integrating the detected spectra of the signal and the noise, the in-band OSNR can be obtained in a very precise manner. We monitor the OSNR values with high accuracy in the range of 10-30 dB.