New discovery by the Utha Engineers who have created the new metamaterial polarizing filter which is used in low light.

1. A
PRESENTATION ON
METAMATERIAL NOVEL POLARIZING FILTER
PREPARED AND SUBMITTED BY
VIRENDRA KUMAR
ELECTRICAL ENGINEERING (3rd YEAR)
ROLL NO: - 1273420059
SEMINAR GUIDE HEAD OF DEPARTMENT
Er. SONALI BARONIYA Dr. DEEPAK NAGARIA
DEPARTMENT OF ELECTRICAL ENGINEERING
Dr. BHIMRAO AMBEDKAR ENGINEERING COLLEGE OF INFORMATION
TECHNOLOGY,BANDA (U.P.)(MENTORED BY B.I.E.T., JHANSI)
AFFILIATED TO UTTAR PRADESH TECHNICAL UNIVERSITY, LUCKNOW
SESSION-2014-15

2. INDEX
Introduction
Metamaterial
Polarizing filter
Working principle of filter
Design of filter
Application
Advantages
Disadvantages
Conclusion
References

3. INTRODUCTION
This new concept in light filtering can perform the same function as a
standard polarizer but allows up to nearly 30% more light to pass
through it.
A new approach to designing a metamaterial polarizer that rotates one
polarization by 90 degree.
It’s a boon for mobile display devices which takes very low power for
operating and also capable for shooting photographs in dim light.
Etching a silicon wafer with nanoscale pillars and holes using a
focused gallium-ion beam.

4. METAMATERIAL
Metamaterials are materials to have properties that have not yet
been found in nature used for filtering light.
They are made from assemblies of multiple elements fashioned
from conventional materials such as metals or plastics.
The materials are usually arranged in repeating patterns.
Their precise shape, geometry,size, orientation and arrangement
gives them their properties.
Metamaterials textured with nanoscale wrinkles could control
sound or light signals.

5. WHAT IS POLARIZING FILTER
A polarizer or polariser is an optical filter that passes light of a
specific polarization.
It can convert a beam of light of undefined or mixed polarization into a
beam with well-defined polarization, polarized light.
Polarizing filters can increase color saturation and decrease reflections.
Polarizers are placed in front of your camera lens, and work by
filtering out sunlight.
This is beneficial because the remaining light is often more diffuse and
colorful.

7. WORKING PRINCIPLE OF FILTER
In order to ensure ease of fabrication, we applied a constraint on the
maximum aspect ratio (defined as the ratio of the maximum etch depth to
the pixel size).
For the fabricated device, the maximum aspect ratio was 2.6.
As the aspect ratio is increased, the transmission efficiency at Ex under
unpolarized input can increase to almost 80%.
The simulated electric-field distributions in the X–Z and Y–Z planes
after transmission through the metamaterial polarizer are shown in Fig.

8. (a) Scanning-electron micrograph of the metamaterial polarizer. One unit cell is 4 μm×4 μm (yellow dashed lines). (b) Magnified
view shows pixels with a period of 400 nm. (c) Measured transmitted power as a function of position in the X–Y plane. The left two
images correspond to the Ey source, while the right two images correspond to the Ex source. Within the device area (dashed white
square), Ey is rotated to Ex. (d) Comparison of the measured peak transmitted power in Ex and Ey between unpatterned silicon and
the metamaterial polarizer

9. DESIGN OF FILTER
The design is composed of etched square pixels in silicon.
We constrained our pixel size to 200 nm×200 nm to enable
fabrication.
Periodic boundary conditions were applied along the X and Y
directions that allowed the unit to be repeated in 2D.
Only 13% of the incident light is reflected, while 74% of the incident
light is transmitted into the desired polarization.

10. (a) High-efficiency metamaterial polarizer. The design (left) is composed of etched square pixels in silicon.
(b)–(e) Simulated light intensity distributions after transmission through the polarizer for (b) Ey and (c) Ex under Ey input
and for (d) Ey and (e) Ex for Ex input. The white dashed lines in (b)–(e) indicate the boundaries of the finite device.

11. APPLICATION’S OF POLARIZING FILTER
Polarizer is used for increasing the colour saturation of pictures.
Since polarizers reduce direct reflections,
This often has the consequence of also reducing image contrast.
It is capable for taking pictures in dim light while using in camera.
It also used for making display devices.

12. ADVANTAGES OF POLARIZING FILTER
Removes haze and gives the sky a deep blue colour.
Cuts off reflections from glass, metals or shiny surfaces, like a sandy
beach on a sunny day, giving clearer, glare-free photos.
Cuts reflections from surfaces like leaves or walls, making colours
appear saturated, and shadows appear blacker.
Can be used as an effective ND filter (neutral density filter), especially
in bright sunlight.

13. DISADVANTAGES OF POLARIZING FILTER
At high altitudes, over-polarization may cause extreme darkening of
the sky and photos may look unnatural
Each photo gets polarized differently and the final ‘stitched’ photo
would have very unevenly coloured skies.
Linear polarizing filters often give focus errors with modern auto-focus
cameras with TTL (through the lens) metering. The way out is to only
use circular polarizing filters with such cameras.
Polarizing filters work best in bright sunny conditions. They’re not of
much use in cloudy, overcast weather or indoors.

14. CONCLUSION
By above analysis we conclude that only 13% light is reflected back
and 74% goes to desired polarization
Appropriate design of these devices can achieve absolute transmission
efficiencies.
Although this device is smaller than the normal conventional
polarizers.
The metamaterial polarizer could be useful where transmission
efficiency is particularly important.

15. REFRENCES
1. J. N. Damask, Polarization Optics in Telecommunications (Springer,
2004).
2. D. S. Kliger, J. W. Lewis, C. E. Randall, Polarized Light in Optics
and Spectroscopy (Academic, 1990).
3. V. V. Tuchin, L. V. Wang, D. A. Zimnyako, Optical Polarization in
Biomedical Applications (Springer, 2006).
4. Y. P. Svirko, N. I. Zheludev, Polarization of Light in Nonlinear
Optics (Wiley, 1998).

16. THANK YOU
FOR
WATCHING