Dual-wavelength InGaAs-GaAs ridge waveguide distributed Bragg reflector lasers with tunable mode separation

The design and operation of integrated dual-wavelength sources are reported . These InGaAs-GaAs ridge waveguide (RW) distributed Bragg reflector (DBR) lasers consist of a common gain section and two, separate DBR sections. Mul tiple current injection is not necessary for these lasers to operate in dua l-wavelength, Dual-wavelength operation is easily achieved by simply biasin g the gain section. A relatively low coupling coefficient kappa in the fron t grating reduces the added cavity loss for the back grating mode. Therefor e, the back grating mode reaches threshold easily. Also, the addition of a spacing section lowers the current induced thermal interaction between the two uniform grating sections, significantly reducing the inadvertent wavele ngth drift. As a result, biasing the front DBR section results in tunable m ode pair separations (Delta lambda) as small as 0.3 nm and as large as 6.9 nm.