Time-dependent measurement of the mode-competition phenomena among longitudinal modes in longwavelength lasers

Modal behaviors of an InGaAsP-InP Fabry-Perot laser emitting in a long-wavelength region were experimentally examined. The authors had predicted theoretically that the mode-competition phenomena induce quasi-periodic hopping among several longitudinal modes, which reveal multimode-like output spectra as the time-averaged spectra in long-wavelength lasers. In this paper, experimental measured data of the time variations of photon number and their frequency spectra in addition to the longitudinal mode spectra are reported together with theoretically simulated results. The previous theoretical predictions were well proved by these experimental measurements.