Photostimulated nonlinear optical switching materials based on CdBr_0·95Cl_0.1 nanocrystalline layers

New types of crystalline materials based on CdBr_0·95Cl_0.1 nanolayers have been fabricated. Due to the layered structure, it is possible to achieve nanolayers by cleaving layers of CdBr₂ single crystals. These layers anisotropy opens a principal opportunity for fabricating thin CdBr_0·95Cl_0.1 nanocrystals with a thickness up to several nanometers without additional treatment. We have prepared the samples within a 3–30 nm thickness range. The phototreatment has been performed by bicolor coherent Nd: YAG laser with wavelengths 1540 nm/770 nm. The third-harmonic generation (THG) was detected for a fundamental 20 ns Er-glass laser beam at wavelength 1540 nm with a frequency reception of ~10 Hz. The phototreatment was done for 2–3 min and was controlled by cw He–Ne laser-induced diffraction patterns. The maximal photoinduced changes have been found for the thinnest film possessing thickness about 3 nm. The THG effect at 1540 nm was maximal at ambient temperature. The effect is explained within a framework of the phenomenological consideration. The principal role of the space electron charge density anisotropy is discussed.