Thermal dissipation is critical for any semiconductor lasers, because heat will lead to their performance degradation, such as wavelength shift, output power decrease, and even device damage. For InP-based InGaAsP semiconductor lasers, heat affection induced by their Auger recombination is so strong that thermal-electronic-controller must be adopted for these lasers operation. Therefore, heat dissipation from up (flip-chip method) and down (heat sink) of these InP-based InGaAsP semiconductor laser has been thoroughly investigated. cladded by the passivation material with high thermal resistance. In this paper, we built two-dimension heat dissipation model by finite-element-method for InP-based InGaAsP FP lasers and investigated the influence of lateral waveguide structure, passivation material, and filling material on the lateral heat dissipation. Our simulation results shows that both the passivation material with low thermal resistance and two-channel waveguide filled with high thermal conductivity material indeed benefit the lateral heat dissipation of these edge-emitting semiconductor lasers. The maximum temperature decrease of 6.8°C in this InP-based InGaAsP ridge waveguide laser with the output power of 18 mW has been achieved in the optimized waveguide structure, where, double-channel waveguide with channel radius of 17 μm and filled with graphene was adopted, the active region is cladded by 300 nm-thick AlN, and then the filling layer of graphene is designed near the InP ridge, and a layer of gold coating with 3.5 μm thickness is deposited on the ridge of the semiconductor laser. Such investigation shows that lateral heat dissipation is possible for these channel waveguide semiconductor lasers. © 2018 SPIE.