Beschreibung:
The growing demand for bandwidth and energy efficiency requires new solutions for signal detection and processing. We demonstrate a concept for high-bandwidth signal detectionwith low-speed photodetectors and electronics. The method is based on the parallel optical sampling of a high-bandwidth signal with sincpulse sequences provided by a Mach-Zehnder modulator. For the electronic detection and processing this parallel sampling enables to divide the high-bandwidth optical signal with the bandwidth B intoN electrical signals with the baseband bandwidth ofB/(2N). In proof-of-concept experiments with N = 3, we present the detection of 24 GHz optical signals by detectors with a bandwidth of only 4 GHz. For ideal components, the sampling and bandwidth down-conversion does not add an excess error to the signals and even for the non-ideal components of our proof-of-concept setup, it is below1%.Thus, the rms error for the measurement of the 24GHz signal was reduced by a factor of about 3.4 and the effective number of bits were increased by 1.8.