Ultrahigh free-electron Kerr nonlinearity in all-semiconductor waveguides for all-optical nonlinear modulation of mid-infrared light

Abstract

Nonlinear optical waveguides, particularly those harnessing the optical Kerr effect, are promising for advancing next-generation photonic technologies. Despite the Kerr effect`s ultrafast response, its inherently weak nonlinearity has hindered practical applications. Here, we explore free-electron-induced Kerr nonlinearities in all-semiconductor waveguides, revealing that longitudinal bulk plasmons (inherently nonlocal excitations) can generate exceptionally strong Kerr nonlinearities. We specifically develop a nonlinear eigenmode analysis integrated with semiclassical hydrodynamic theory to compute the linear and nonlinear optical responses originating from the quantum behavior of free electrons in heavily doped semiconductors. These waveguides achieve ultrahigh nonlinear coefficients exceeding 10${}^7$ W${}^{-1}$km${}^{-1}$ and support long-propagating modes with propagation distances over 100 $\mu$m. Additionally, we confirm the robustness of the nonlinear response under realistic conditions by considering viscoelastic and nonlinear damping mechanisms. Finally, we implement our all-semiconductor waveguides in a Mach-Zehnder interferometer, demonstrating efficient nonlinear modulation of the transmittance spectrum via the free-electron Kerr effect. This work evidences the transformative potential of free-electron nonlinearities in heavily doped semiconductors for photonic integrated circuits, paving the way for scalable on-chip nonlinear nanophotonic systems.

References in corpus (18)

• All-optical signal processing platforms for CMOS compatible integrated nonlinear optics
• Breaking the Loss Limitation of On-chip High-confinement Resonators
• Resonance shifts and spill-out effects in self-consistent hydrodynamic nanoplasmonics
• Unusual resonances in nanoplasmonic structures due to nonlocal response
• Second and Third Harmonic Generation in Metal-Based Nanostructures
• Quantum Hydrodynamic Theory for Plasmonics: Impact of the Electron Density Tail
• Nonlocal Response of Metallic Nanospheres Probed by Light, Electrons, and Atoms
• Quantum Effects in the Nonlinear Response of Graphene Plasmons
• Transition from plasma- to Kerr-driven laser filamentation
• Nonlocal response in thin-film waveguides: loss versus nonlocality and breaking of complementarity
• Kerr nonlinearity and plasmonic bistability in graphene nanoribbons
• Current-dependent exchange-correlation potential for non-local absorption in quantum hydrodynamic theory
• Nonlocal response in plasmonic waveguiding with extreme light confinement
• An electronic-based model of the optical nonlinearity of low-electron-density-Drude materials
• Free electron nonlinearities in heavily doped semiconductors plasmonics
• Nonlinear optical heating of all-dielectric super-cavity: efficient light-to-heat conversion through giant thermorefractive bistability
• Theory of coherent optical nonlinearities of intersubband transitions in semiconductor quantum wells
• Omnidirectional field enhancements drive giant nonlinearities in epsilon-near-zero waveguides