Abstract

We demonstrate an RF photonic fractional Hilbert transformer based on an integrated Kerr micro-comb source featuring a record low free spectral range of 48.9 GHz, yielding 75 microcomb lines across the C-band. By programming and shaping the comb lines according to calculated tap weights, we demonstrate that the Hilbert transformer can achieve tunable bandwidths ranging from 1.2 to 15.3 GHz, switchable centre frequencies from baseband to 9.5 GHz, and arbitrary fractional orders. We experimentally characterize the RF amplitude and phase response of the tunable bandpass and lowpass Hilbert transformers with 90 and 45-degree phase shift. The experimental results show good agreement with theory, confirming the effectiveness of our approach as a powerful way to implement the standard as well as fractional Hilbert transformers with broad and switchable processing bandwidths and centre frequencies, together with high reconfigurability and greatly reduced size and complexity.

Integrated frequency comb source based Hilbert transformer for wideband microwave photonic phase analysis

Thach G. Nguyen, Mehrdad Shoeiby, Sai T. Chu, Brent E. Little, Roberto Morandotti, Arnan Mitchell, and David J. Moss
Opt. Express 23(17) 22087-22097 (2015)

Integrated reconfigurable photonic filters based on interferometric fractional Hilbert transforms

C. Sima, B. Cai, B. Liu, Y. Gao, Y. Yu, J. C. Gates, M. N. Zervas, P. G. R. Smith, and D. Liu
Appl. Opt. 56(28) 7978-7984 (2017)

Terahertz-bandwidth photonic fractional Hilbert transformer based on a phase-shifted waveguide Bragg grating on silicon

Maurizio Burla, Ming Li, Luis Romero Cortés, Xu Wang, María Rosario Fernández-Ruiz, Lukas Chrostowski, and José Azaña
Opt. Lett. 39(21) 6241-6244 (2014)

Wideband and continuously-tunable fractional photonic Hilbert transformer based on a single high-birefringence planar Bragg grating

Zijing Zhang, Chaotan Sima, Bolan Liu, Binchen Cai, Yuan Gao, Minming Zhang, Li Shen, Yu Yu, Meng Huang, Zhenggang Lian, Matthew T. Posner, James C. Gates, Peter G.R. Smith, and Deming Liu
Opt. Express 26(16) 20450-20458 (2018)

Novel microwave photonic fractional Hilbert transformer using a ring resonator-based optical all-pass filter

Leimeng Zhuang, Muhammad Rezaul Khan, Willem Beeker, Arne Leinse, René Heideman, and Chris Roeloffzen
Opt. Express 20(24) 26499-26510 (2012)