Microwave and RF photonic fractional Hilbert transformer based on a 50 GHz Kerr micro-comb

Mengxi Tan, Xingyuan Xu, Bill Corcoran, Jiayang Wu, Andreas Boes, Thach G. Nguyen, Sai T. Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, David J. Moss

Research output: Contribution to journalArticleResearchpeer-review

35 Citations (Scopus)


We report a photonic microwave and radio frequency (RF) fractional Hilbert transformer based on an integrated Kerr micro-comb source. The micro-comb source has a free spectral range (FSR) of 50 GHz, generating a large number of comb lines that serve as a high-performance multi-wavelength source for the transformer. By programming and shaping the comb lines according to calculated tap weights, we achieve both arbitrary fractional orders and a broad operation bandwidth. We experimentally characterize the RF amplitude and phase response for different fractional orders and perform system demonstrations of real-time fractional Hilbert transforms. We achieve a phase ripple of <0.15 rad within the 3-dB pass-band, with bandwidths ranging from 5 to 9 octaves depending on the order. The experimental results show good agreement with theory, confirming the effectiveness of our approach as a new way to implement high-performance fractional Hilbert transformers with broad processing bandwidth, high reconfigurability, and greatly reduced size and complexity.

Original languageEnglish
Pages (from-to)6097-6104
Number of pages8
JournalJournal of Lightwave Technology
Issue number24
Publication statusPublished - 15 Dec 2019


  • All-optical signal processing
  • Hilbert transform
  • integrated optics
  • Kerr frequency comb

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