74. consider the laser resonator cavity shown in the figure. r,-1 rg r > m m2 m and a is the gain coefficient of the if 7, is the intensity of the radiation at

74. Consider the laser resonator cavity shown in the figure. R,-1 Rg R > M M2 M and a is the gain coefficient of the If 7, is the intensity of the radiation at mirror medium between the mirrors, then the energy density of photons in the plane P at a distancee x from M, is A. (1,/c)e B. (1,/c)e -ax C. (1,/c)e te a )D. (1,/c)ea