Using a solar cell as a qualitative test of laser intensity

[trini]

so I am testing out different designs on a nitrogen laser, and wanted a quick way to test whether or not one design had a more intense output than the other. without having to buy a sensor, my idea was to direct the beam onto a solar cell, then measure the output current. higher current wud mean higher intensity. is this a reasonable assumption for the test?

 

[trini]

nothing? =(

 

[cbetanco]

so I am testing out different designs on a nitrogen laser, and wanted a quick way to test whether or not one design had a more intense output than the other. without having to buy a sensor, my idea was to direct the beam onto a solar cell, then measure the output current. higher current wud mean higher intensity. is this a reasonable assumption for the test?

Yes, that is the easiest way. I work with silicon detectors for ATLAS, and they are essentially solar cells. This is what we do to measure the intensity of a laser in the lab.

 

[trini]

great thanks =)

 

[NobodySpecial]

If it's a very small spot you might want to diffuse it a little - solar cells have structures on the surface (electrodes etc) so the response might depend on exactly where on the cell you hit.

Try moving the sensor around by a few mm as you measure and see if there is any difference in the current

 

[Dr Lots-o'watts]

so I am testing out different designs on a nitrogen laser, and wanted a quick way to test whether or not one design had a more intense output than the other. without having to buy a sensor, my idea was to direct the beam onto a solar cell, then measure the output current. higher current wud mean higher intensity. is this a reasonable assumption for the test?

Knowing the wavelength, here's what you may expect as a response:
http://en.wikipedia.org/wiki/File:Response_silicon_photodiode.svg

If ever you need accurate measurements of average cw power or single pulse energy, google "laser power meter".