Stimulated Rayleigh–Bragg Scattering From a Two-Photon Absorbing CdSe–CdS–ZnS Quantum-Rods System: Optical Power Limiting and Phase-Conjugation

This work reports the properties of stimulated Rayleigh–Bragg scattering (SRBS) from a two-photon absorbing CdSe–Cds–ZnS quantum-rods (QRs) solution in chloroform, excited by 1064-nm and $\sim$13-ns laser pulses. The two-photon absorbing capability of the scattering medium, as well as the pump threshold, spectral structure, and pulse waveforms of the backward stimulated scattering were measured. Comparing to a pure solvent or an organic dye-solution, the semiconductor QR system has many advantages such as the lower pump threshold, higher energy transfer efficiency, and better photo-physical and photo-chemical stability. The measured output/input characteristic curve shows that the backward SRBS can enhance the optical power limiting performance that is based on two-photon absorption, backward stimulated scattering, and other nonlinear absorption mechanisms. In addition, the backward SRBS beam from our sample medium exhibits a fairly good optical phase-conjugation capability, so that the distortion influence from an inserted aberrator can be automatically removed.