Strained multiquantum-well corrugation-pitch-modulated distributed feedback laser with ultranarrow (3.6 kHz) spectral linewidth

Abstract
Introducing a 1% compressive strained multiquantum-well (MQW) active layer into a corrugation-pitch-modulated distributed feedback (CPM-DFB) laser reduces the linewidth floor (residual linewidth for extrapolated infinite output power) to 2 kHz and results in a linewidth-power product of 140 kHz mW. Strained MQW CPM-DFB lasers produced a 55 mW output with a spectral linewidth of only 3.6 kHz.