Semiconductor Laser Using Multimode Interference (MMI) Principle

Multimode interference (MMI) structure is introduced in semiconductor laser to realize higher power and shorter device length. We use BPM simulation in the device design. MMI-LD was fabricated and realized in InGaAsP/InP based material and output power of up to 2.296 mW was achieved. The implemented MMI-LD exhibits stable single-mode output operating at a wavelength of 1.52 mum at 10degC. As a comparison, conventional semiconductor laser using straight waveguide is also fabricated in the same wafer and the output power is 0.534 mW. MMI-LD also shows better temperature tolerance due to the MMI wavelength selecting function.