Open AccessTheoretical and experimental study of hybrid optical computing engine for arbitrary-order FRFT
Author(s) -
Jiaying Hong,
Xi Zhou,
Nian Xin,
Zhengyu Chen,
Bin He,
Zhangwei Hu,
Ning Zhang,
Li Qin,
Ping Xue,
Xiao Zhang
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.443223
Subject(s) - fractional fourier transform , chirp , demodulation , computer science , fourier transform , algorithm , optics , signal processing , frequency domain , discrete fourier transform (general) , telecommunications , physics , mathematics , fourier analysis , computer vision , mathematical analysis , laser , channel (broadcasting) , radar
Fractional Fourier transform (FRFT) is the generalization of Fourier transform. It provides many significant advantages, such as fractional order as the new degree of freedom and high efficiency and great performance for non-stationary signal analysis/processing, that other operations including Fourier transform cannot. Here, we report a hybrid optical system for computation of arbitrary-order FRFT of temporal signals. In experiment, the fractional-domain information of input temporal signals could be directly acquired by detector. In addition, the optical computing results are in good agreement with numerical results. Then we apply the optical computing engine to demodulation of chirp spread spectrum signals. Using sub-Nyquist sampling, the proposed technology could greatly save the number of measurements in demodulation. The compression ratio could be as low as 0.4%, because of the high compression performance of chirp signals in FRFT domain. As a result, the proposed technology has unique advantages in analysis and information extraction for non-stationary signals, especially for chirp-like signals, and may become a powerful optical time-frequency analysis tool for temporal signals.