Investigation of Wavelength Switching Performance of a SSG-DBR-LD for Optical Packet Switch Application

摘要

The wavelength switching performance of a superstructure-grating DBR laser (SSG-DBR-LD) has been investigated. The lasing wavelength could be selected by directly modulating the wavelength tuning region with the switching time of less than a few nanoseconds. We observed that the pulse width of the output signal in each lasing wavelength monotonically changed with increasing the injection current amplitude when the low level of injection current was fixed. This is considered to be due to the increase of transient time from high level to low level of injection current when the amplitude increases and time duration for carrier density to satisfy the lasing mode at the low level of injection current decreases. For improving the stability of the pulse width of the output signal, a novel method of the mean level of injection current pulse fixed is proposed. Almost the same pulse width for wavelength switching from one supermode to another has been realized because the low level of injection current becomes lower than the conventional method and the time duration for carrier density to satisfy the lasing mode at the low level of injection current increases.