Megahertz-frequency large-area optical modulators at 1.55 μm based on solution-cast colloidal quantum dots

We report the realization of large-area, communications-wavelength electro-optic modulators made via simple solution-casting onto an arbitrary substrate. The devices employ colloidal quantum dots synthesized in, and processed from, the solution phase. Devices exhibit greater than 30% modulation depth at the 1.55 mu m eye-safe wavelengths of interest in free-space optical communications. The devices retain considerable modulation depth beyond 1 MHz. (C) 2008 Optical Society of America.