Title :
Dispersion of phonon-assisted nonresonant third-order nonlinearities
Author_Institution :
Bell Labs., Holmdel, NJ, USA
Abstract :
An analysis of the dispersion of two-photon absorption and Kerr nonlinearity of indirect semiconductors below the indirect bandgap is presented. Similar to the case of linear absorption, third-order nonlinear processes are found to be mediated by phonon-assisted transitions. The Kerr coefficient n2 is positive below the indirect gap, and the dispersion of the third-order nonlinearities is reduced relative to direct semiconductors. The results are compared with existing experimental data in silicon.
Keywords :
electron-phonon interactions; elemental semiconductors; energy gap; infrared spectra; optical Kerr effect; optical dispersion; semiconductors; silicon; transparency; two-photon spectra; Kerr nonlinearity; Si; dispersion; indirect bandgap; indirect semiconductors; near-infrared wavelengths; phonon-assisted nonresonant third-order nonlinearities; positive Kerr coefficient; silicon; third-order nonlinear processes; transparency region; two-photon absorption; two-photon absorption spectrum; Absorption; Nonlinear optical devices; Nonlinear optics; Optical devices; Optical filters; Optical refraction; Optical ring resonators; Photonic band gap; Silicon; Ultrafast optics;
Journal_Title :
Quantum Electronics, IEEE Journal of
DOI :
10.1109/JQE.2003.818277
