Numerical study on lateral mode behavior of 660-nm InGaP/AlGaInP multiple-quantum-well laser diodes

Theoretical analysis for InGaP/AlGaInP laser diodes with different ridge waveguide structures is performed to investigate the lateral mode behavior using advanced device simulation. The internal physical mechanisms including temperature-induced changes in the refractive index profile, spatial hole burning effect, lateral carrier distribution, and gain profile variation with increasing input current are discussed by theoretical calculation to analyze the effects of different ridge structures on the lateral mode behavior of 660-nm AlGaInP laser diodes. The simulation results show that the use of narrow and shallow ridge geometry is the approach to obtaining single mode operation. Furthermore, it is found that the different values of the ridge height cause the lateral carrier distribution within the active region to be varied, which is also an important factor in determining the emergence of the first order lateral mode in addition to the geometry-dependent waveguide cutoff condition.