Accurate wavelength spacing from absorption-coupled DFB laser arrays

Six-element absorption-coupled distributed-feedback (DFB) arrays have been fabricated by means of holographic lithography. Using a simple current injection scheme in two-section devices, a standard deviation of 0.11 nm from a uniform wavelength channel spacing of 2 nm has been achieved. This value is easily obtained using standard lithography technologies for fabrication, and coarse current control for operation. It allows the use of complex-coupled DPB lasers as sources in photonic integrated circuits.