Patent ID: 7826062

Claim:
A device for detecting optical signals at a certain optical wavelength with a high resolution, the optical signals to be detected modulating an optical carrier having a freely selectable carrier wavelength , the device comprising: means structured and arranged for generating at least one reference light ray, which is at least one of a frequency shifted, frequency modulated, phase shifted, phase modulated or time displaced relative to said optical carrier; means ( 20 , 30 ) structured and arranged for aligning said optical carrier modulated by the signals to be detected with said at least one reference light ray such that said at least one of the optical carrier modulated by the signals to be detected and said at least one reference light ray are brought to interference in such manner that the period of spatial modulation of a resulting spatial interference pattern occurring at a detector is larger than a detected portion of the resulting interference pattern detected by said detector; and a detector ( 40 ) with a demodulator ( 50 ) being structured and arranged to detect intensity modulation of a resulting signal from said interference; wherein an angular dispersive element ( 11 , 12 , 14 ) is structured and arranged to change an angle of at least one of the optical signals and said at least one reference light ray being brought into interference depending upon wavelength; and said detector ( 40 ) is structured and arranged to measure a modulation of intensity of at least part of cross-section of the resulting detected signal.