Demonstration of a 40-dB side mode suppression ratio hybrid laser built through an FP-laser diode with an antireflection coating whose thickness was controlled by direct observation of the laser emission spectrum

In this communication we demonstrate the implementation of an external cavity fiber grating laser with a side mode suppression ratio higher than 40 dB utilizing a Fabry-Perot laser diode with a facet containing an antireflection coating which thickness is controlled by a technique allowing the direct observation of the laser resonance behavior during the application process.