Microwave frequency measurement using a finite impulse response system that incorporates Lorentzian profile-weighted optical taps

Abstract

We propose an advanced photonic microwave processing scheme useful for the accurate measurement of incoming microwave signal frequency over a wide frequency bandwidth. Our scheme is based on a finite impulse response system using Lorentzian profile-weighted multiple optical wavelength taps. Unlike the conventional schemes based on two optical taps, our scheme allows for well-defined, linear mapping of the incoming microwave frequency onto the output electrical power utilizing a log scale. In order to verify the principle, an experimental demonstration was carried out by using a multiwavelength channel beam, which was produced by the combination of a broadband, continuous wave supercontinuum and a digital micromirror device-based spatial light modulator. An excellent frequency measuring performance over a range of 1-9 GHz was achieved.

Decoherence and equilibration under nondestructive measurements

“…Lorentzian distribution arises when measurement is realized by means of optical beams [40]. Two usually considered types of measurements are instantaneous [39,40] and continuous [39,41,55] measurements.…”

“…Because of this, the effect density of measuring devices is commonly represented by Gaussians [39,[54][55][56]. Lorentzian distribution arises when measurement is realized by means of optical beams [40]. Two usually considered types of measurements are instantaneous [39,40] and continuous [39,41,55] measurements.…”

“…Throughout the paper, the word "measurement" is used as a conditional term describing time-dependent influence on the system of an external nonequilibrium source. In addition, two limiting cases of the source influence, instantaneous and continuous, which will be analyzed in the paper, have the forms that are commonly associated with measurements [39][40][41]. Therefore the interpretation of the time-dependent source influence as measurement seems to be justified.…”