試題詳解

25. You need 14 W of infrared laser light power with wavelength 1270 nm to bore a hole in a diamond. How many downward atomic transitions per second must occur in the laser if all of them result in light directed onto the diamond? (c = 3.00 x 10⁸m/s, h=6.62610^-34J·s)
(A)2.7 x 10¹⁸,
(B) 8.9 x 10¹⁹,
(C) 9.8 x10¹⁸,
(D) 5.9 x 10¹⁹,
(E) 1.4 x 10¹⁸