DBR Laser With Over 20-nm Wavelength Tuning Range

We report a widely tunable distributed Bragg reflector (DBR) laser, in which InGaAsP with 1.4-
$\mu \text{m}$
photoluminescence wavelength is butt-jointed as the DBR section material. A titanium (Ti) thin-film heater is integrated in the DBR section of the device. With the help of the tuning effect of the heater, an over 20-nm wavelength tuning range is obtained. The DBR laser is a promising light source for future wavelength division multiplexing passive optical networks.