Nano Archive

A nonvolatile plasmonic switch employing photochromic molecules

Pala, Ragip A. and Shimizu, Ken T. and Melosh, Nicholas A. and Brongersma, Mark L. (2008) A nonvolatile plasmonic switch employing photochromic molecules. NANO LETTERS, 8 (5). pp. 1506-1510.

Full text is not hosted in this archive but may be available via the Official URL, or by requesting a copy from the corresponding author.

Official URL: http://dx.doi.org/10.1021/nl0808839

Abstract

We demonstrate a surface plasmon-polariton (SPP) waveguide all-optical switch that combines the unique physical properties of small molecules and metallic (plasmonic) nanostructures. The switch consists of a pair of gratings defined in an aluminum film coated with a 65 nm thick layer of photochromic (PC) molecules. The first grating couples a signal beam consisting of free space photons to SPPs that interact effectively with the PC molecules. These molecules can reversibly be switched between transparent and absorbing states using a free space optical pump. In the transparent (signal ``on'') state, the SPPs freely propagate through the molecular layer, and in the absorbing (signal ``off'') state, the SPPs are strongly attenuated. The second grating serves to decouple the SPPs back into a free space optical beam, enabling measurement of the modulated signal with a far-field detector. In a preliminary study, the switching behavior of the PC molecules themselves was confirmed and quantified by surface plasmon resonance spectroscopy. The excellent (16%) overlap of the SPP mode profile with the thin layer of switching molecules enabled efficient switching with power densities of similar to 6.0 mW/cm(2) in 1.5 mu m x 8 mu m devices, resulting in plasmonic switching powers of 0.72 nW per device. Calculations further showed that modulation depths in access of 20 dB can easily be attained in optimized designs. The quantitative experimental and theoretical analysis of the nonvolatile switching behavior in this letter guides the design of future nanoscale optically or electrically pumped optical switches.

Item Type:Article
Subjects:Physical Science > Nanophysics
Physical Science > Nano objects
Analytical Science > Beam methods
ID Code:2386
Deposited By:Anuj Seth
Deposited On:17 Dec 2008 12:57
Last Modified:20 Jan 2009 10:25

Repository Staff Only: item control page