Large on-chip Brillouin net amplification in silicon-based nano-photonics

Hyeongpin Kim,Heedeuk Shin

doi:10.1063/1.5125699

Abstract

Recent developments in on-chip forward Brillouin scattering open up potential applications such as RF photonic signal processing, on-chip Brillouin amplification, and on-chip Brillouin lasers. The stimulated Brillouin scattering gain coefficients become significant with a small optical mode area, and the Brillouin net amplification has been believed to be strong with a small mode area, too. However, here, we present a theoretical study of higher net amplification with a large optical mode area than that with a small mode area and explain this counter-intuitive phenomenon by examining the contribution of various optical forces to Brillouin gain coefficients for various optical waveguide dimensions. The simulation results show that a waveguide with large optical waveguide dimensions can yield significant net amplification by high Brillouin gain coefficients and low optical losses at high pump power even if the Brillouin gain coefficients are lower than that with a small waveguide dimension. Therefore, it is necessary to optimize the optical waveguide dimensions to achieve maximum net amplification for the development of Brillouin lasers and amplifiers in silicon-based nanophotonics.

Highlights

Large nonlinear optical effects in silicon photonics have been of great interest to the physics and signal processing communities due to their wide range of applications.[1]
In Ref. 20, two Brillouin active membrane (BAM) waveguides with a fixed phononic dimension of 3.8 μm, but with different photonic waveguide widths of 313 nm and 950 nm, were experimentally examined; the results showed that the operational bandwidth is wider with the 313-nm BAM waveguide, but the stimulated Brillouin scattering (SBS) gain coefficients at low frequencies are comparable to each other
The operation bandwidth due to the SBS effect is examined for various photonic waveguide widths b = [250, 300, 500, 1000, 2000]

Summary

Introduction

Large nonlinear optical effects in silicon photonics have been of great interest to the physics and signal processing communities due to their wide range of applications.[1]. The contributions of electrostrictive (ES) forces and radiation pressure (RP) to the SBS gain coefficients and operation bandwidth are investigated numerically for different optical waveguide dimensions.

Results

Conclusion