Abstract

Integrated photonics technologies have allowed for the miniaturization of frequency comb sources unlocking cheap, compact, energy-efficient, and scalable platforms for frequency comb generation [1]. On-chip comb sources, however, suffer from an inherent trade-off between programmability and bandwidth. Broadband combs lack FSR and spectral envelope control, while programmable combs, e.g. EO-based combs, are limited in bandwidth [2]. Here, we present a novel approach that enables processing of a narrowband comb to extend its bandwidth. Exploiting the nonlinear dynamics of a multi-wavelength laser (MWL) subject to frequency comb injection, we show spectral multiplication of the original comb at programmable offset frequencies of 28 GHz, 56 GHz, and 1.304 THz. By relying then on a integrated optical feedback loop including a phase modulator, our technique allows simultaneous or selective emission of the different combs with a characteristic switching time between states of about τ_s = 7 ns. By adjusting the laser design, additional offset frequencies can be obtained, thus enabling the processing of broadband combs, such as selective amplification, for applications in spectroscopy, microwave signal generation, or Lidar.

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