The master equation of a three-level atomic system interacting with a two-mode field at two-photon resonance is given. The two-photongain coefficient formula is deduced.
给出了阶梯型三能级原子系统在相等偏调情况下的运动主方程，得到了双光子增益系数公式。
2
Analyzing the carrier density and photon density of VCL in active region, the physical mechanism of gain clamping was revealed.
分析有源区内载流子和VCL光子密度的变化，揭示了增益钳制的物理机理。
3
Using rate equation theory, the equation group including the population inversion density of the gain medium, photon density and the absorber ground state population density is acquired.