Fabrication and characterization of an electrically variable, nanospring based interferometer

The authors report on an electrically variable Fabry-Pérot interferometer constructed from the organic material tris(8-hydroxyquinoline) aluminum (Alq3). A two-turn helical Alq3 film with a 300nm pitch is deposited via glancing angle deposition. Electrostatic compression of the nanosprings between parallel, partially reflective mirrors controls the peak transmission wavelength. Contact mode atomic force microscope measurements using a conductive tip indicate a spring compression of 1.2nm when a voltage of 6V is applied across the structure. Spectroscopic measurements show a 1.6nm shift in the peak transmission wavelength. These results demonstrate precise control of the transmission wavelength of an electrically variable nanometer scaled interferometer.