We propose and demonstrate the operation of a new 1.3‐&mgr;m wavelength GaInAsP semiconductor laser: the double active layer (DAL) crescent laser and compared its device performances with regular single active layer (SAL) crescent laser fabricated under similar procedures. While the regular SAL crescent lasers (∼250 &mgr;m cavity) tested were in general multilongitudinal moded, the DAL crescent lasers (both 300 and 125 &mgr;m) were highly single‐longitudinal moded for the entire current range tested (up to 3Ith), even under transient fast pulse excitation (high‐bit rate modulation) and showed stability to mode hopping. DAL crescent lasers with short cavity (∼125 &mgr;m) operated stably in the same single‐longitudinal mode under fast constant current pulse excitation at all time starting from the onset of optical pulse and approach the characteristics of distributed Bragg reflector lasers in spectral purity and stability.