Photonic crystal reflectance switching by dye electrophoresis
My paper was published in Applied Physics Letters on August 2, 2010.
Reflectivity of a photonic crystal device fabricated by glancing angle deposition may be reversibly
altered by infiltration with an absorbing dye solution. An electric field controls the dye ion motion
through the photonic crystal. Rapid reflectance changes up to 0.4 in the crystal’s optical band gap
are demonstrated. The time evolution of the dye movement process is examined and its operation
described. This work may have applications for a passive optical display. © 2010 American Institute
of Physics. doi:10.1063/1.3473827
The figures follow:
FIG. 1. (a) Bragg stack photonic crystal microstructure fabricated using GLAD. (b) Schematic representation of assembled cell, not to scale. Reflectance is measured from the top surface.
FIG. 2. (a) Reflectance ranges achieved when driving the cell with 800 mV. Negative polarity yields a reflectance minimum, whereas positive polarity drives dye out of the crystal for a reflectance maximum. (b) Maximal reflectance variation (λ = 715 nm) driven at three voltages. Same reflectance scale as left.
FIG. 3. (a) A reflectance time response of the cell at 715 nm when addressed with a driving voltage of 1000 mV. (b) The calculated characteristic time constants of the optical response. Driving voltages of 600 mV, 800 mV, and 1000 mV are shown in light, medium, and dark gray, respectively. Gray borders indicate wavelengths where rise or fall behavior resembled a clipped exponential.
If you’re interested in a copy of the .pdf of this paper and cannot download it from the internet you’re welcome to contact me and I will pass it along via email.