Abstract. One of the best ways achieving to strong coupling, is nano particles embedded in nano-cavity of photonic crystals. In this paper, Hamiltonian of the interaction of nano-particle - photon, based on semiclassical approach was computed. Then total Hamiltonian of this nano system, by Rotating Wave Approximation (RWA) is calculated. By solving this Hamiltonian in Schrödinger equation, eigen values of this system, energy level shift factor and the strong coupling regime conditions for InAs/GaAs quantum dots embedded in the photonic crystal is obtained. For three cavities by decay rates of 200μeV, 600μeV and 1000μeV and drawing diagram (ΔE- γc-g) presents that when cavity decay rate decreasing, both coupling constant and energy level shift are increased. This means that, only for high quality factor cavities, Strong-coupling will occur. Actually slope of coupling constant diagram more than slope of decay rate of cavity. This means that coupling constant plays more important role for achieving to strong coupling regime.
