How to measure the speed of light with this setup

This is an experiment I’ll be undertaking for labs.

Given the following equipment:
– laser with modulation input
– lenses and mirrors
– function generator
– high-speed photo detectors
– oscilloscope

and the setup as shown in the picture (the function generator is connected to the laser power, the laser power’s connected to the laser, the laser sends a beam of light towards a mirror, the mirror reflects the beam of light, the beam of light then goes through a lens and into the photodiode, which is hooked up to the oscilloscope via a variable resistor), how would you measure the speed of light?

From this source* (looks like a similar experiment, though I’m struggling to understand it), the function generator would be turning the laser on and off, so it’ll be arriving at the detector in pulses.
I’m not sure how the oscilloscope is used in this – if each pulse creates a peak then the wavelength would just be related to the frequency at of the function generator, though I’m not sure how that comes in either.

Attached Images
File Type: png setup.png (33.7 KB)

Leave a comment

Your email address will not be published.


Show Buttons
Hide Buttons