Bending Light With Light For Mini-Devices

Combining surface plasmon polaritons with non-linear liquids is a promising way of controlling the polarization of light.

AsianScientist (Jul 23, 2014) – Scientists have developed a method of filtering polarized light that can enhance transmission thousand-fold, paving the way for miniaturization of optical devices. This research has been published in Modern Physics Letters B, a journal by World Scientific Publishing Co.

Optical circuits have attracted the attention of scientists for their increased bandwidth and lower interference as compared to traditional electrical circuits. Although light has been used for data transmission (fiber optics), the use of light in circuitry has been limited by impracticalities including the inability to control the direction of light at the nanoscale.

One common method of shifting the polarization direction of linearly polarized light is the use of the half-wave plate, which constructed out of a birefringent material such as quartz or mica. The behaviour of a half-wave plate depends on the thickness of the crystal and the wavelength of light. However, half-wave plates are difficult to integrate on circuits due to the complexity of fabricating the crystal required.

Surface plasmon polaritons (SPPs) are an alternative approach to controlling polarization at the nanoscale. SPPs are electromagnetic waves that can be guided along a metal surface. Because SPPs are able to breach the diffraction limit, some devices based on SPPs are superior to traditional optical components for integrated optical circuits.

In the present study, led by Dai Jin from the Beijing University of Posts and Telecommunications, a SPP-based polarization filter composed of a nanocavity array filled with non-linear medium is proposed. Theoretical calculations and simulations showed that the structure can realize polarization separation as well as filtering, enhancing the transmission of low intensity light thousand fold.

Furthermore, the authors showed that the transmission peak output could be modulated by varying the incident light intensity. Taken together, these findings demonstrate a feasible method for constructing nanoscale optical logical gates and all-optical switches; this ability to control light with light might be helpful for integrated optical circuits and on-chip optical interconnects.

The article can be found at: Dai et al. (2014) Plasmon-Enhanced Polarization-Selective Filter Based On Multiple Holes Array Filled With Nonlinear Medium.


Source: World Scientific Scientific Co.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

Asian Scientist Magazine is an award-winning science and technology magazine that highlights R&D news stories from Asia to a global audience. The magazine is published by Singapore-headquartered Wildtype Media Group.

Related Stories from Asian Scientist