Device, in particular a semiconductor device, for processing two waves, in particular light waves

A device, in particular a semiconductor device, for processing two waves, in particular light waves, said device including:

• a first processing member which operates such that desired processing is performed on waves having a first wavelength;
• a second processing member which operates such that desired processing is performed on waves having a second wavelength, operation of said second processing member requiring protection to be provided for said second member against waves having the first wavelength;
• and
• a separator absorbing the waves having the first wavelength, which separator is interposed between the first processing member and the second processing member in order to provide said second member with said protection;
• said device further including absorption measurement means delivering an absorption measurement signal representative of the power of the waves absorbed by said separator so as to include information on operation of said first processing member.