title: Photonic generation of low phase noise arbitrary chirped microwave waveforms with large time-bandwidth product.
abstract: We present a photonic approach for generating low phase noise, arbitrary chirped microwave waveforms based on heterodyne beating between high order correlated comb lines extracted from frequency-agile optical frequency comb. Using the dual heterodyne phase transfer scheme, extrinsic phase noises induced by the separate optical paths are efficiently suppressed by 42-dB at 1-Hz offset frequency. Linearly chirped microwave waveforms are achieved within 30-ms temporal duration, contributing to a large time-bandwidth product. The linearity measurement leads to less than 90 kHz RMS frequency error during the entire chirp duration, exhibiting excellent linearity for the microwave and sub-THz waveforms. The capability of generating arbitrary waveforms up to sub-THz band with flexible temporal duration, long repetition period, broad bandwidth, and large time-bandwidth product is investigated and discussed.
authors.forename: Weilin
authors.initials: W
authors.lastname: Xie
authors.forename: Zongyang
authors.initials: Z
authors.lastname: Xia
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhou
authors.forename: Hongxiao
authors.initials: H
authors.lastname: Shi
authors.forename: Yi
authors.initials: Y
authors.lastname: Dong
authors.forename: Weisheng
authors.initials: W
authors.lastname: Hu