Optical system and method for performing analog to digital conversion
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorsLars Thylén, Sverker Hård, Urban Westergren, Mehran Mokhtari
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Abstract
An opto-electronic A/D converter includes a tunable laser for wavelength modulating a narrowband coherent electromagnetic beam by the amplitude of the analog signal. A grating transforms the wavelength modulated beam into a corresponding angularly modulated beam. A set of kinoforms diffract the angularly modulated beam into a bundle of diffracted beams. Detectors determine the digital signal by repeatedly sampling the spatial power distribution of the diffracted beams.
Claims12
An opto-electronic method of converting an analog signal into a digital signal, comprising the steps of:
- wavelength modulating a narrowband coherent electromagnetic beam such that the wavelength variation is a monotonic function of the amplitude of said analog signal;
- transforming said wavelength modulated beam into a corresponding angularly modulated beam;
- diffracting said angularly modulated beam into a bundle of diffracted beams;
- and
- determining said digital signal by repeatedly sampling the spatial power distribution of said diffracted beams.
An opto-electronic apparatus for converting an analog signal into a digital signal, comprising:
- means for wavelength modulating a narrowband coherent electromagnetic beam by a monotonic function of the amplitude of said analog signal;
- means for transforming said wavelength modulated beam into a corresponding angularly modulated beam;
- means for diffracting said angularly modulated beam into a bundle of diffracted beams;
- and
- means for determining said digital signal by repeatedly sampling the spatial power distribution of said diffracted beams.
Dependencies are inferred from the claim text.