Ahe-ne laser, with the resonator length of 100 cm, has a doppler linewidth ∆νd = 1.5 ghz and midband gain coefficient γ(νo) = 2 x 10-3 cm-1. the length of the resonator d = 100 cm, and the reflectance of the mirrors are 98 % and 97% (all other resonator losses are negligible). assuming that the refractive index n = 1, determine the frequency spacing νf between the resonator modes and the number of laser modes