Single-longitudinal-mode operation of DFB lasers in gain-switched operating conditions

Single-longitudinal-mode operation under a gain-switched condition, generating 20 ps optical pulses, has been attained in DFB lasers emitting at 1.3 mu m wavelength. It has been clarified that Delta lambda , which is the difference between the DFB wavelength and the gain peak wavelength, plays an important role in stable single-mode operation. The optimum range of Delta lambda wave found to be in the range from -15 nm to 0 nm.