Wideband excitation of Fano resonances and induced transparency by coherent interactions between Brillouin resonances

Abstract

Wideband excitation and control of Fano resonance and electromagnetically induced transparency (EIT), both of which rely on coherent interaction between two excitation paths, is challenging. It requires precise control and tuning of interacting resonances or coupling between different resonant structures over a wide frequency range. Gain (Stokes) and absorption (anti-Stokes) resonances associated with the stimulated Brillouin scattering (SBS) process can be excited and controlled over a wide frequency range by tuning the pump frequency, its power and profile. We exploit coherent interaction between the Brillouin Stokes and anti-Stokes resonance, in radio frequency domain, to demonstrate Fano and EIT-like resonance over a wide frequency range and control their shape and strength optically and electrically. For the Fano resonance, the asymmetry and polarity are electrically controlled over an unprecedented frequency range (100 MHz–43 GHz) by varying the bias to the intensity modulator whereas, the strength is varied by tuning the Brillouin pump power and/or the bias. The depth and 3 dB linewidth of the transparency window in the EIT-like resonance are controlled using pump and probe parameters. The flexibility of the SBS process that allows wideband electrical and optical control of Fano and EIT-like resonance opens up the potential for applications that range from low-power switching, sensing to tunable RF delay.

Mitigation of Dispersion Induced Impairments in Brillouin-Based Microwave Photonic Bandpass Filter

“…The working principle remains the same as that of the DSB-PM based MPBF except the introduction of a bias dependent phase shift tan −1 α. The optical filed at the output of a z-cut IM is given as [43],…”

Microwave photonics applications of stimulated Brillouin scattering

“…SBS is one of the strongest non-linear optical processes. Extensive control over the SBS parameters makes it desirable in a wide range of applications such as signal processing [13,14,42,[75][76][77][78], sensors [79][80][81][82], Brillouin dynamic grating [83][84][85][86], frequency measurements [87][88][89][90] and slow-light [91][92][93]. Frequencies ranging from 300 MHz to 300 GHz in the electromagnetic spectrum are generally termed as microwave.…”