Patent ID: 8379223

Claim:
A device ( 10 , 20 ) for detecting a phase difference between two light beams, said device including: a diffraction grating ( 2 ) which can generate an interference field between said two light beams; a photodiode ( 1 , 5 ) which is arranged to receive the interference field; said diffraction grating being integrated to said photodiode, characterised in that said diffraction grating is an amplitude grating ( 2 ), wherein said amplitude grating is a metallic grating positioned on said photodiode; and lower ( 6 ) and upper ( 3 ) metallic contacts, a voltage generator ( 9 ) being liable to be connected between the lower ( 6 ) and upper ( 3 ) metallic contacts, so as to generate a difference in potential within said photodiode with the amplitude grating ( 2 ) being at least partially in electric contact with the upper contacts ( 3 ).