High-performance two-photon absorption optical limiter and stabilizer based on phase-pure thick-shell CdSe/CdS core/shell quantum dots

Abstract

Abstract To achieve high-sensitivity two-photon absorption (2PA) optical limiters and stabilizers, two-photon active materials need to have large 2PA cross-sections. Phase-pure wurtzite (WZ) CdSe/CdS core/shell quantum dots (QDs) with a shell thickness of 11 CdS monolayers were prepared by a high-temperature pyrolysis method, which possess a large volume and nearly defect-free core/shell interfaces. The 2PA cross-section of QDs is measured to be as large as 1.5 × 105 GM by the nonlinear transmittance method. Due to the large 2PA cross-section of phase-pure thick-shell WZ CdSe/CdS core/shell QDs, we successfully explored their application in the field of optical limiting and stabilization. Finally, we successfully fabricated a high-sensitivity optical stabilizer made of a polymer (polymethylmethacrylate) matrix comprising phase-pure thick-shell WZ CdSe/CdS core/shell QDs, which can reduce the amplitude fluctuation by ∼67%. In addition, the device reduces the input energy by ∼40%, indicating that the device can also be applied as an optical limiter. This work promotes the application of optical limiters and stabilizers based on QDs in practical work to a certain extent.