Complex third-order nonlinear optical susceptibility spectrum of a CdS film coat on a silver nanoparticle

We have fabricated a CdS-coated Ag nanoparticle using the reverse micelle method and observed the nonlinear optical response of the scattered light intensity caused by an individual particle. In addition, we succeeded in obtaining the complex third-order nonlinear susceptibility χ(3) spectrum near the energy band edge of the CdS film by comparing the experimental result and the result of the Mie calculation that considered the optical Kerr effect of the CdS. At ħωi = 2.43 eV, the χ(3) of the CdS was (1.1 + i0.6) × 10−17m2/V2. We conjecture that an increase in the carriers in the interband transition of the CdS originates from the increase in the χ(3) of the CdS at ħωi > 2.4eV.