An optical micro-comb with a 50GHz free spectral range for photonic microwave true time delays

Abstract

We demonstrate significantly improved performance of a microwave true time delay line (TTDL) based on an integrated micro-ring resonator (MRR) Kerr optical comb source with a channel spacing of 49GHz, corresponding to 81 channels over the C-band. The broadband microcomb, with a record low free spectral range of 49GHz, results in a large number of comb lines for the TTDL, greatly reducing the size, cost, and complexity of the system. The large channel count results in a high angular resolution and wide beam steering tunable range of the phased array antenna (PAA). The enhancement of PAA performance matches well with theory, corroborating the feasibility of our approach as a competitive solution towards implementing compact low-cost TTDL in radar and communications systems.

6 pages, 3 figures, 56 references, to be published in OSA Photonics Research journal special issue on integrated nonlinear optics

References in corpus (3)

• Generation of very flat optical frequency combs from continuous-wave lasers using cascaded intensity and phase modulators driven by tailored radio frequency waveforms
• Parametric gain and wavelength conversion via third order nonlinear optics a CMOS compatible waveguide
• Integrated Fabry-Perot cavities as a mechanism for enhancing micro-ring resonator performance