Two continuous-wave lasers operate simultaneously in a physics laboratory
PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
Two continuous-wave lasers operate simultaneously in a physics laboratory. Laser A emits photons with a wavelength of 500 nm, while Laser B emits photons with a wavelength of 250 nm. Both lasers operate in vacuum.
Assume any fundamental constants needed are available on the exam information sheet.
(a) Without performing numerical calculations, state which laser produces photons with greater energy and justify your answer qualitatively.
(b) Derive an algebraic expression for the ratio EB/EA of the energy of a photon from Laser B to that from Laser A in terms of their wavelengths only.
(c) If the energy of a single photon from Laser A is measured to be 2.48 eV, calculate the energy of a photon from Laser B.
(d) A third laser, Laser C, is designed to emit photons whose frequency is exactly twice that of Laser A. Determine the wavelength of photons emitted by Laser C.