200mW 405nm single-frequency laser diodes based on a GaN DFB-MOPA architecture

We present novel 405 nm DFB LDs that are monolithically integrated with an amplifier section in a master oscillator power amplifier (MOPA) architecture. By employing this efficient two-section DFB MOPA architecture, single-lateral-mode and single-longitudinal-mode operation with large side mode suppression ratios exceeding 40 dB is demonstrated at output power levels up to 200 mW in continuous mode and up to 400 mW in pulsed operation. The two-section chip design allows driving the DFB LD section in its optimal single-frequency window while the output power is controlled by current injection in the amplifier section, thereby further enhancing the optimum control of the wavelength/power parameters of these single-frequency lasers.