Abstract

Wavelength-tunable laser diodes will be important components in future photonic network systems based on WDM technologies.^1,2 Broadly tunable lasers^3–5 are capable of addressing any wavelength over a range of 30–60 nm, which exceeds the gain bandwidth of an Er-doped fiber amplifier (EDFA). Application of these devices in a photonic network system requires precise control of the oscillation wavelength and mode stability. In DBR-type tunable lasers, any change in the device characteristics may cause not only wavelength shifts, but also mode-hopping. The wavelength change caused by the mode hopping is so large that the wavelength could move out of the locking range if a conventional feedback circuit is used. Therefore, reflectivity-control of DBR is necessary in order to stabilize the oscillation mode.

© 2002 Optical Society of America