Low latency microwave photonic RTFT processing based on bandwidth slicing and equivalent dispersion

Microwave photonic real-time Fourier transformation (RTFT) processing based on optical dispersion is a promising solution for microwave spectrum analysis. However, it usually brings the drawbacks of limited frequency resolution and large processing latency. Here, we demonstrate a low-latency microwave photonic RTFT processing based on bandwidth slicing and equivalent dispersion. The input RF signal is first divided into different channels with the help of bandwidth slicing technique, and then finely analyzed by the fiber-loop based frequency-to-time mapping. In the proof-of-concept experiment, a 0.44-m fiber-loop offers an equivalent dispersion as high as 6x10(5) ps/nm with a small transmission latency of 50 ns. As a result, we can realize a wide instantaneous bandwidth of 1.35 GHz, a high frequency resolution of approximately 20 MHz, and a high acquisition frame rate of approximately 450 MHz, together with a total latency of less than 200 ns. (c) 2023 Optica Publishing Group

Automated summary

This study demonstrates a low-latency microwave photonic real-time Fourier transformation (RTFT) processing technique based on bandwidth slicing and equivalent dispersion. It achieves wide bandwidth spectrum analysis, high frequency resolution, high acquisition frame rate, and total latency of less than 200 ns.