Abstract
Ultrafast absorptive nonlinearity of excitons is enhanced in a Bragg reflector in which quantum wells are periodically distributed. Absorptive excitonic nonlinearity in the exciton Bragg reflector is characterised by femtosecond transient transmission and reflectance measurements with e–h pair density far above the exciton saturation density. The absorptive excitonic nonlinearity is dominated by two-photon absorption enhanced under the optical confinement in this Bragg reflector. Optical frequency shift caused by ultrafast refractive index change due to the enhanced two-photon absorption, is evaluated from frequency-resolved absorption transients. Spectral modulation of optical pulses and the resultant pulse chirping are produced by this frequency shift and the optical pulses reflected from the exciton Bragg reflector are compressed by compensating the pulse chirping.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.