Dual-wavelength laser source monolithically integrated with Y-junction coupler and isolator using quantum-well intermixing

A dual-wavelength laser source monolithically integrated with an isolator and a Y-junction coupler is fabricated by using a new quantum-well intermixing technique. The technique employs a buried Ge layer between the sample surface and the spin-on silica film to control the bandgap tuning in selective areas across a wafer. The integrated isolator can avoid the crosstalk between the two channels of the device. Two distinct lasing wavelengths of 950 and 969 nm are coupled into one single output port through the transparent Y-junction coupler. The two channels have similar threshold current and slope efficiency.