Optical metasurfaces are inscribed in surface relief on azobenzene molecular glass thin films following double and triple sequential exposures to laser interference patterns with very close periodicities, resulting in two-fold and three-fold hierarchical Moiré gratings respectively. These metasurfaces formed due to the unique photomechanical effect in azobenzene materials, in which molecules migrate from zones of high to low laser irradiance. The laser interference patterns were obtained using a Lloyd mirror interferometer and a continuous wave laser having a wavelength of 532 nm and an irradiance of 200 mW/cm2. The resulting optical metasurfaces, which resembled surface features of a Peruvian lily flower petal, were characterized using atomic force microscopy, optical microscopy and surface profilometry techniques. It was found that the highly-customizable surface characteristics of the resulting metasurfaces can significantly alter their hydrophobicity.
Chirped-pitch crossed surface relief gratings (CP-CSRGs) were fabricated on photoactive azobenzene thin films using a simple two-step procedure. The resulting gratings had a constant pitch in one direction and a varying (chirped) pitch in the orthogonal direction. They were coated with silver and tested for their ability to excite surface plasmon resonance (SPR). It was observed that incident light can be transmitted or blocked on different locations of the CP-CSRG device only as a function of the light’s wavelength. These SPR-based sensors were used to detect changes in the refractive index of aqueous sucrose solutions and a maximum sensitivity of 778.6 nm/RIU was obtained.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.