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US 9,438,263 B1Granted
Controllable opto-electronic time stretcher, an electro-optical analog to digital converter having non-uniform sampling using the same, and related methods of operation
AssigneeHRL Laboratories, LLC
InventorsWillie W. Ng, Mohiuddin Ahmed, Troy Rockwood
Life of this patent
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Abstract
A controllable opto-electronic time stretcher comprising a first wave guide and a second waveguide coupled to the first waveguide along a coupling portion; wherein at least one of the first and second waveguides in the coupling portion has a controllable refractive index.
Claims21
A method of sampling an analog signal having a predetermined spectrum, the method comprising:
- when said analog signal corresponds to a K sparse vector of N coefficients, with K<<N, using one or more opto-electronic devices, spreading in time said analog signal according to a predetermined pseudo-random pattern into a pseudo-randomly time-spread signal;
- on a predetermined time period, taking M samples by sampling the pseudo-randomly time-spread signal at a predetermined rate, said predetermined rate being lower than the Nyquist rate, where M≧K.log(N/K);
- associating the M samples to the time at which they would have been taken if said analog signal had been spread uniformly during said time period by a spread factor equal to the mean of the pseudo-randomly spread factor on said time period;
- and
- determining iteratively the closest output signal that would have allowed extracting the M samples at their associated times.
2 more elements
An electro-optical analog to digital converter having non-uniform sampling, comprising:
- a source of light arranged for generating at least one light pulse having a first spectral width;
- a chirp element arranged for spreading in time the wavelengths of said at least one light pulse;
- an electro-optic modulator arranged for modulating the time-spread light pulse with an input analog signal into a modulated optical signal;
- at least one controllable opto-electronic time stretcher arranged for variably spreading in time the modulated optical signal according to a predetermined non-uniform pattern;
- at least one sampler arranged for sampling at a predetermined rate the out put of the at least one controllable opto-electronic time stretcher;
- and
- a calculator arranged for constructing a digitized image of the input analog signal based on the samples generated by the at least one sampler and based on said predetermined non-uniform pattern.
4 more elements
A method of converting an analog input signal into a digital output signal, the method, comprising:
- generating at least one light pulse having a first spectral width;
- spreading in time wavelengths of said at least one light pulse;
- modulating the time-spread light pulse with said input analog signal into a modulated optical signal;
- controllably time stretching the modulated optical signal according to a predetermined non-uniform pattern;
- sampling at a predetermined rate an output of a first and a second waveguide;
- and
- constructing a digital output signal corresponding to a digitized image of the analog input signal, based on the samples generated by the sampling and based on said predetermined non-uniform pattern.
4 more elements
Dependencies are inferred from the claim text.