Three common laboratory laser pointers emit monochromatic light at the wavelengths…
PHYSICS · Multi-part · A Level · Physics · Particles and radiation · Particles and radiation
Problem
Three common laboratory laser pointers emit monochromatic light at the wavelengths listed in the table.
Laser Pointer
Wavelength (nm)
I (violet)
405
II (green)
532
III (red)
650
Answer the following questions about the individual photons produced by these lasers.
(a) Calculate the frequency, in Hz, of the photons emitted by each laser pointer. Show your work for one calculation; the others may be reported directly if your method is clear.
(b) Determine the energy, in J, of a single photon from each laser pointer. Report your answers to three significant figures.
(c) Rank the three lasers from highest to lowest photon energy. State the numerical factor by which the most energetic photons exceed the least energetic photons.
(d) A researcher needs photons of at least 3.70×10−19J each for a fluorescence experiment. Indicate which, if any, of the three laser pointers meets this requirement and justify your choice with quantitative evidence.