深圳大学电子科学与技术学院 三输出功率与能量 In section 4.1 we derived an expression for the threshold population inversion at which the laser gain becomes equal to the losses. We would expect that as the pumping intensity is increased beyond the point at which N -=m the laser will break into oscillation and emit power. In this section we obtain the expression relating the laser power output to the pumping intensity. We also treat the problem of optimum coupling-that is. of the mirror transmission that results in the maximum power output深圳大学电子科学与技术学院 三 输出功率与能量 • In section 4.1 we derived an expression for the threshold population inversion at which the laser gain becomes equal to the losses. We would expect that as the pumping intensity is increased beyond the point at which N2 -N1 =Nt the laser will break into oscillation and emit power. In this section we obtain the expression relating the laser power output to the pumping intensity. We also treat the problem of optimum coupling-that is, of the mirror transmission that results in the maximum power output