title: Periodic modulation-based spectral and temporal superresolution with a single measurement.
abstract: In a superresolution technique, based on periodic modulation of the signal to be tested, high resolution is obtained for a large number of modulation harmonics. However, the number of measurements, required for measuring one quantity, is equal to the number of harmonics. Two techniques of spectral and temporal superresolution with a single measurement, based on replication of the signal, are proposed and numerically demonstrated. In the first one, replication and modulation lead to sampling and compression in the Fourier transform domain. It is shown that an optical spectrum analyzer with a resolution of 0.01 nm (1.25 GHz) is capable of measuring 1 MHz spectral lines with a resolution of 60 kHz, using the superresolution technique proposed. The spectrum is magnified by a factor of 10,000. Similarly, the measurement of 1.7 ps optical pulses with a resolution of 44 fs can be performed with a 30 GHz real-time oscilloscope. The magnification factor is 160. In the second proposed method, the parts of the signal Fourier transform for each replica are shifted into the system passband. This method is useful for measurement of very long single-shot ultrafast temporal waveforms.
authors.forename: Naum K
authors.initials: NK
authors.lastname: Berger