Analysis of Self-Homodyne and Delayed Self-Heterodyne Detections for Tunable Laser Source Linewidth Measurements

Abstract

The linewidth characteristic of a commercial tunable laser source (TLS) is experimentally demonstrated with two different linewidth measurement methods; homodyne and heterodyne detections. With 25km of SMF as a delay fiber and wide mode operation, the linewidths of 124 MHz, 114 MHz and 176 MHz are obtained at operating wavelengths of 1530 nm, 1540 nm and 1560 nm, respectively. The linewidth of the TLS is obtained at around 10 MHz and 150 MHz for narrow and wide modes, respectively with heterodyne technique.