# How do you calculate the wavelength of a helium-neon laser that says 95mW on it?

## I have already done a diffraction grating but would like to double check that my results are accurate. I thought that calculating the wavelength of the laser I had used would give me more marks. Is it even possible to calculate the wavelength like this? Thanks

632.8 nm is the normally quoted wavelength, giving a frequency of 4.74 x ${10}^{14}$ Hz.