Metamaterial is electrically switched from reflector to absorber

Sept. 1, 2010
An electrically controllable metamaterial developed by a group at Nanjing University (China) can be switched to independently reflect or absorb light for either or both TE and TM polarizations; the effect is valid for incidence angles ranging from 0° to 50°.

An electrically controllable metamaterial developed by a group at Nanjing University (China) can be switched to independently reflect or absorb light for either or both TE and TM polarizations; the effect is valid for incidence angles ranging from 0° to 50°. Like many metamaterial prototypes, this structure was fabricated for use at microwave wavelengths, where the unit cell size is on the order of 10 mm and thus easy to make. Also like many of the prototypes, the researchers say the concept can potentially be applied at optical frequencies, where the unit size would shrink to much less than a micron.

The metamaterial actually contains two independent layers, one to switch each polarization. Each layer contains an array of electric-LC (inductor-capacitor) resonators on top of a dielectric, with a metallic film underneath. The wave impedance of the metamaterial matches that of free space; a resonance causes absorption of the microwaves. A forward-bias voltage on the diodes created in the structure causes the resonance to be destroyed, boosting reflection. The reflection is continuously tunable from zero to maximum. The figures show reflection of the metamaterial for the two orthogonal polarizations (TE and TM) at various incidence angles with the diodes either on (applied voltage) or off (no voltage). Contact Yijun Feng at [email protected].

Sponsored Recommendations

March 31, 2025
Enhance your remote sensing capabilities with Chroma's precision-engineered optical filters, designed for applications such as environmental monitoring, geospatial mapping, and...
March 31, 2025
Designed for compatibility with a wide range of systems, Chroma's UV filters are engineered to feature high transmission, superior out-of-band blocking, steep edge transitions...
March 31, 2025
Discover strategies to balance component performance and system design, reducing development time and costs while maximizing efficiency.
March 31, 2025
Explore the essential role of optical filters in enhancing Raman spectroscopy measurements including the various filter types and their applications in improving signal-to-noise...

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!