Real-time Fourier transformer using one acousto-optical cell

摘要

An optical Fourier transformer comprising a laser which is modulated by the signal to be analyzed, a beam splitter for dividing the beam into two beams which are directed by optical means to opposite sides of a Bragg cell with the corresponding rays in the two beams striking opposite ends of the Bragg cell. A chirp signal impressed upon the Bragg cell causes each of the beams incident thereon to produce a diffracted beam. The diffracted beams are recombined by optical means with the corresponding rays becoming coincident and the recombined beams are directed to a time-integrating photo-detector array. The distribution of intensities on the array is related to the Fourier transform.