Patent ID: 8686712

Claim:
An apparatus for recovering signals and removing distortion in a photonic Time Stretched Analog-to-Digital Converter (TS-ADC), comprising: a modulator configured for receiving a pulsed optical source and configured for modulating sequential segments of a received electrical input signal over a pulsed optical source; a plurality of dispersion elements configured for receiving segments of said pulsed optical source from said modulator and stretching them in the time domain into a plurality of stretched optical pulses containing the stretched analog signal; a plurality of optical detectors coupled to analog-to-digital converters (ADC) adapted for converting the stretched analog signal into a digital signal configured for receiving each of said stretched optical pulses and converting each of them into a digital signal; a digital multiplexer configured for combining each of the sequential segments of said digital signal into a single digital output; a processor coupled to said digital multiplexer; programming executable on said processor for performing one or more of the following digital signal processing steps to remove distortion as selected from the group of distortion removal processing consisting of: (a) performing broadband linearization by emulating a transfer function of the physical system under test which is subtracted from a scaled version of the captured waveform; (b) performing envelope correction by obtaining pulse envelope, common mode noise, and differential, then subtracting common mode noise from the differential and dividing by the envelope; (c) performing time warp removal to eliminate distortions resulting from non-uniform stretching across the optical spectrum based on interpolation of a model of time warp magnitude; and (d) performing bias offset removal in response to determining a second harmonic amplitude and subtracting a function of the harmonic amplitudes from the uncorrected signal.