The active medium in a particular laser that generates laser light at a wavelength of 694 nm is 6.00 cm long and 1.00 cm in diameter.
(a) Treat the medium as an optical resonance cavity analogous to a closed organ pipe. How many standing-wave nodes are there along the laser axis?
(b) By what amount f would the beam frequency have to shift to increase this number by one?
(c) Show that f is just the inverse of the travel time of laser light for one round trip back and forth along the laser axis.
(d) What is the corresponding fractional frequency shift Δf/f? The appropriate index of refraction of the lasing medium (a ruby crystal) is 1.75.