Ultralow Noise And Supermode Suppression For High-Speed Photonic Sampling With A Semiconductor Diode Ring Laser

Ultralow noise and supermode suppression for high-speed photonic sampling with a semiconductor diode ring laser were discussed. High dynamic range measurements out to Nyquist offsets were presented which show strong supermode suppression to levels below -140 dBc/Hz. The loss-modulated laser geometry is such that the free-space section contains extensive isolation and polarization-controlling optics surrounding an InGaAsP SOA. For supermode suppression, a high-finesse fiber Fabry-Perot filter and 3-ring polarization controller are inserted before the Mach-Zehnder modulator