Optical switch based on thermally-activated dye-doped biomolecular thin films

A new optical switch has been developed, based on laser-induced heating and the temperature-dependent fluorescence emission properties of biomolecular thin films comprised of the phospholipid 15OPC. For films doped with the Laurdan dye probe, a 200 mW CW Nd:YAG laser (1060 nm) was used to heat submicron thick films by /spl sim/5/spl deg/C, and induce switching between two phase states of the bilayer, at the peak emission wavelengths of 440 nm and 490 nm, with rise and fall times of 50 ms and 275 ms, respectively. The thermal switching times are shown to be dependent on the initial device setpoint temperature, and the thermal sensitivity of the film in the phase transition region.<
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