Spectral characteristics of InGaAsP/InP injection C3 lasers

An investigation was made of the frequency tuning range and the longitudinal mode discrimination in a C³ (cleaved-coupled-cavity) laser with a variable gap. The conditions for maximum discrimination of spurious modes were obtained. For any gap, the mode discrimination in a C³ laser was higher than that in a laser with a plane–plane resonator. The amplitude mode noise was maximal when the operating point was selected to ensure equal intensities of the modes between which switching took place and was minimal when tuned to the single-mode regime.