Question

Exercise 6 The upper laser level lifetime of Nd:YAG and Nd:glass Lasers are respectively 230 μs and 320 us. Assume that both Nd:YAG and Nd:glass laser materials are doped to the same Nd concentration of 1026 /m3. Assume they are both pumped identically, so that they have approximately 0.1% of Nd3+ ions in the upper level. Compare the radiated power of a cubic volume 10 mm on a side from each of these materials. Assume that both materials radiate at approximately the same wavelength of 1.06 μm

Answer 1

The radiative power of Nd: YAG = P = E/t E = total energy emitted by laser life time of energy level = t concentration of Nd + 3ions = 1. 0e + 26/m^3 energy of each photon = hc/ lambda = 1.8740e - 019J h = planks constant = 6.626le - 034 J.sec c = light velocity = 3.0e + 08 m/s lambda = laser wavelength = 1.06e - 6 m the energy emitted from 10 mm cube volume = E E = 10^26 /m^3 times (10e - 3)^3 times 0.001 times hc/ lambda = 1.8740e + 004 J life time of Nd + 3ions in Nd1.8740e + 004: YAG t = 230e - 6s power of radiation = P = E/t = 1.8740e + 004 J/230e - 6s = 8.1478e + 007 W similarly radiative power of Nd: glass = P' = E/t' = 1.8740e + 004 J/320e - 6s = 5.8562e + 007 W ratio of the power emitted by Nd: YAG with ND: glass = P/P' = 1.3913