Monolithically integrated 650 nm and 780 nm semiconductor lasers with aluminum-free active areas

Summary form only given. The digital versatile disk (DVD) has been increasingly prevalent for high-density data storage and readout applications. To meet the requirements of being able to read not only the DVD signals but also the signals from the traditional compact disc (CD), the conventional DVD pickup heads are typically equipped with two separate laser diodes with wavelengths at 650 nm and 780 nm for DVD and CD read-out respectively. It would be most desirable and advantageous to integrate two separate lasers into one single chip that can allow the reduction of the optical components, the pick-up head size, the assembling time, and the over-all costs. Integration of red and infrared laser was reported but the infrared wavelength is not suitable for CD application. In the work we report the realization of monolithic integration of two wavelength laser diodes in a single chip with two emission wavelengths at 650 nm and 780 nm using two substantially different laser material structures with aluminum-free active areas and MOCVD re-growth technique.