Fabrication of 780-nm AlGaAs tunable distributed Bragg reflector laser diodes by using compositional disordering of a quantum well

AlGaAs tunable distributed Bragg reflector (DBR) laser diodes (LD's) with a lasing wavelength of 780 nm were fabricated by means of electron beam (EB) lithography, ion implantation, and two-step metalorganic vapor phase epitaxy (MOVPE). Active and passive waveguides were monolithically integrated by using silicon ion implantation for compositional disordering of quantum-well heterostructures. The optimum single-quantum-well (SQW) structure, with low threshold current and low internal loss, is about 5 nm thick and has an Al mole fraction of 0.06. The graded-index separate-confinement heterostructure (GRIN-SCH) with a carrier-blocking layer was also used to improve the characteristic temperature of a two-step-growth LD. A Iinewidth as narrow as 690 kHz and a frequency tuning of more than 1.7 THz were obtained.