A surgical laser with a wavelength of $10 nm delivers 250 m.W of power on the retina of a patient. It produces a 1.5 msec duration pulse of light. 1. What is the energy of each photon? (30%) E=h* v=h *c / wavelength (6.6 * 10%-34) (3 * 10 9) / 810 * 10"-9 =2.44 *10"-19 J 2. What is the laser energy per pulse? (30%) Epulse = Pt Epulse = (250 * 10^-3) (1.5 * 10^-3) =3.75 *10"-4 J 3. How many photons does it produce? (30%) (3.75 *10%-4 )) / (2.44 * 10"-19 J) = 1.53 * 10 15 4. In what region of the spectrum is this light? (10%) The infrared region