Photonic generation of linearly chirped millimeter wave based on comb-spacing tunable optical frequency comb

Abstract

We demonstrated a photonic approach to generate a phase-continuous frequency-linear-chirped millimeter-wave (mm-wave) signal with high linearity based on continuous-wave phase modulated optical frequency comb and cascaded interleavers. Through linearly sweeping the frequency of the radio frequency (RF) driving signal, high-order frequency-linear-chirped optical comb lines are generated and then extracted by the cascaded interleavers. By beating the filtered high-order comb lines, center frequency and chirp range multiplied linear-chirp microwave signals are generated. Frequency doubled and quadrupled linearchirp mm-wave signals of range 48.6 to 52.6 GHz and 97.2 to 105.2 GHz at chirp rates of 133.33 and 266.67 GHz∕s are demonstrated with the AE1st and AE2nd optical comb lines, respectively, while the RF driving signal is of chirp range 24.3 to 26.3 GHz and chirp time 30 ms.

The design of a flexible RF generator for driving Acousto-Optical devices in space applications

“…Additionally, the AOFS can be utilized to delay an optical signal applied in a fiber [8]. This can be used to investigate the behavior of a cavity semiconductor laser, by applying the delayed self-heterodyne interferometric technique [9].…”