High-Power Semiconductor Laser Fabricated by Standard Photolithography for Direct Modulation

High-power semiconductor laser with an integrated master oscillator power amplifier (MOPA) based on the surface-slotted structure is demonstrated. The lasing wavelength of $1.5~\mu \text{m}$ is achieved by using a group of micron-level slots fabricated by standard photolithography. The laser exhibits continuous-wave output power of up to 225 mW in the single-mode operation at room temperature. At the maximum output power, the modulation bandwidth is larger than 7 GHz, demonstrating the excellent performance of the MOPA based on the surface-slotted structure.