where a stationary detector at D, intersects the wave fronts at,
\(f=\cfrac{v}{\lambda_s}\)
For a piece of metal with photoelectric threshold frequency of \(f_T\), embedded in a low resistance semiconductor, \(v\) is the speed of light in the semiconductor, then
\(\lambda_s=\lambda_T\)
where \(\lambda_T\) is the corresponding threshold wavelength. We have,
\(f=f_T\)
The problem with this is being totally confused with particle wave duality.
However;
Given a small enough metal surface area, are the electrons emitted/detected at \(f\)? Only if the light is pulsed at \(f\). So, given a wave train pulsed at \(f_p\),
\(f_p=\cfrac{v}{\lambda_p}\)
\(n_s=\cfrac{\lambda_p}{\lambda_s}\)
where \(n_s\) is the refractive index at the detector.
\(f=f_pn_s\)
\(f\) can then be modulated by changing \(n_s\).
If \(n_s\) changes with gravity as in an aerogel or the like, we then have an instantaneous gravity detector. No more swinging pendulum, LPPL indeed.
