Abstract
In this paper we present a physical discussion of the indirect two-photon absorption (TPA) occuring in silicon carbide with either cubic or wurtzite structure. Phonon-electron interaction is analyzed by finding the phonon features involved in the process as depending upon the crystal symmetry. Consistent physical assumptions about the phonon-electron scattering mechanisms are proposed in order to give a mathematical formulation to predict the wavelength dispersion of TPA and the Kerr nonlinear refractive index n2. The TPA spectrum is investigated including the effects of band nonparabolicity and the influence of the continuum exciton. Moreover, a parametric analysis is presented in order to fit the experimental measurements. Finally, we have estimated the n2 in a large wavelength range spanning the visible to the mid-IR region.
Highlights
There are over two hundred chemically stable semiconducting polytypes of silicon carbide (SiC) that have a high bulk modulus and a generally wide band gap
The first demonstration of the self-phase modulation (SPM) effect in a 4H-SiC channel waveguide has been reported in ref. 15, where the Kerr nonlinear refractive index n2 = 8.6 × 10−15 cm2/W has been estimated for a pump beam centered at 2360 nm
The goal of this section is to evaluate the theoretical wavelength dispersion for the third-order absorption occurring in 3C, 4H and 6H SiC polytypes
Summary
There are over two hundred chemically stable semiconducting polytypes of silicon carbide (SiC) that have a high bulk modulus and a generally wide band gap. The ability to grow epitaxially high-quality SiC crystal on different substrates, most notably on silicon, provides advantages that facilitate the fabrication of nanophotonic cavities2,3 For these reasons and because of its unique physical properties and mechanical/chemical stability, SiC is considered to be a promising platform for electronic and photonic applications. Heretofore, none of Group IV platforms based on CMOS-compatible exhibits simultaneously a large bandgap, a bulk second-order susceptibility χ(2), a high third-order χ(3) susceptibility and a refractive index above 2.0 This desired combination of characteristics could be realized in the SiC platform, especially devices enabled by “SiC-on-insulator” wafers (SiC/ SiO2/Si) that would offer linear and nonlinear photonic devices at visible wavelengths. The nonlinear optical (NLO) response of 3C, 4H and 6H SiC structures could open up a wide range of applications such as four-wave mixing, wavelength conversion, third harmonic generation, infrared parametric amplification, frequency comb generation, continuum generation, and self-phase modulation, covering the optical spectrum from the visible through the mid infrared
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
