Abstract

Wavelength tunable semiconductor lasers are promising for wavelength division multiplexing (WDM) and optical cross connection systems.^1-5 In particular, distributed Bragg reflector (DBR) lasers are attractive because of their fast wavelength tunability and capability of integration with other optical elements such as electro-absorption modulator. Only drawback for tunable DBR lasers is that it is necessary to control two independent currents to avoid mode jumping within the whole tuning range. Therefore, an attempt has been made for single current continuous wavelength tuning in the DBR laser by adding a control circuit for balancing injection currents into phase control (PC) and DBR regions.³ However, complete continuous tuning was so difficult to be achieved that mode jumping still limited tuning range because the nonlinear relation existed between the injection current and the refractive index variation in PC and DBR regions.

© 1995 IEEE