Abstract
We report the ultrafast and large third-order nonlinear optical properties of CdS nanocrystals (NCs) embedded in a polymeric film. The CdS NCs of 2 nm radius are synthesized by an ion-exchange method and highly concentrated in the two layers near the surfaces of the polymeric film. The two-photon absorption coefficient and the optical Kerr coefficient are measured with laser pulses of 250 fs duration at 800 nm wavelength. The one-photon and two-photon figures of merit are determined to be 3.1 and 1.3, respectively, at irradiance of 2 GW/cm2. The observed nonlinearities have a recovery time of ∼1 ps. The two-photon-generated free carrier effects have also been observed and discussed. These results demonstrate that CdS NCs embedded in polymeric film are a promising candidate for optical switching applications.
| Original language | English |
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| Pages (from-to) | 4373-4376 |
| Number of pages | 4 |
| Journal | Journal of Physical Chemistry B |
| Volume | 109 |
| Issue number | 10 |
| DOIs | |
| State | Published - 17 Mar 2005 |
| Externally published | Yes |