<p>A high-frequency signal sampling approach by combining with compressive sensing and random equivalent sampling technology is proposed. The proposed sampling method achieves ∼10 times faster equivalent sampling rate by utilizing three parallel sub-Nyquist low-rate analog-to-digital converters (TPSL-ADC). By the union of the optical electric-field sensor with wide dynamic range and the proposed TPSL-ADC sampling method, a complete high-frequency electric-field signal measurement system has been realized. The high-frequency electric-field signal with an equivalent sampling rate of 1 GS / s is captured by utilizing three parallel ADCs with sampling rates of ∼32.3, 31.3, and 30.3 MS / s, respectively. The effectiveness of the proposed electric-field sensing and detecting system has been experimentally demonstrated.</p>
As for the issue of the rapid wavelength interrogation of optical fiber wavelength-encoded sensor, a demodulation method combining spectrum-to-time domain information mapping and photonics time stretch technology is proposed. Using group velocity dispersion effect of dispersive elements, the spectrum of optical pulse will be mapped to a temporal waveform whose intensity mimics the spectrum. The temporal waveform is further stretched in timescale so that it is slow enough to be captured by electronic analog-to-digital converter. The performance of the proposed demodulation method is experimentally demonstrated to demodulate a wavelength-encoded sensor.