A DBR LASER EMPLOYING PASSIVE-SECTION HEATERS, WITH 10.8 NM TUNING RANGE AND 1.6 MHZ LINEWIDTH

A novel wavelength-tunable, three-section, distributed Bragg reflector (DBR) laser diode is demonstrated. The refractive indices of the DBR section and the phase-control section are thermally controlled by thin -film heaters embedded on these passive sections. This structure enabl es wide-range wavelength tuning without the spectral linewidth broaden ing accompanying conventional tuning by current injection into the pas sive sections. A tuning range of 10.8 nm and a linewidth of less than 1.6 MHz have been achieved in the 1.5 mum wavelength region. The tempe rature increase in the active layer is held to within a few degrees, e ven when the DBR-section temperature reaches 90-degrees-C.