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Liquid Crystal Lenses Presentation On By: Dheeraj Kumar

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Presentation on theme: "Liquid Crystal Lenses Presentation On By: Dheeraj Kumar"— Presentation transcript:

1 Liquid Crystal Lenses Presentation On By: Dheeraj Kumar
M.Tech (Nanotechnology)

2 Rigid Fixed Shape Fixed Volume Not Rigid No Fixed Shape Fixed Volume Not Rigid No Fixed Shape No Fixed Volume

3 Solid LC Liquid

4 Why Liquid Crystal? Molecular re-orientation under the influence
of an electric field Deformation in shape of LC under field induced

5 Applications of LC LC Lenses Displays and Projectors Thermometers
Light Modulators and Switched Material Testing Chemical Probes Rewritable Optical Data Storages

6 Liquid Crystal Lenses Principle:
In 1977 by Bricor Principle: Change in the electric field applied to the LC, leads to the change in the refractive index of material

7 Working Conventional: If the surface of the isotropic medium is polished with a spherical shape, then it functions as a Lens Positive Lens: Incident ray experiences a gradually increment in refractive index from the border to center Negative Lens: Incident ray experiences a gradually decrement in refractive index from the border to center

8 Conventional: If the surface of the isotropic medium is polished with a spherical shape,
then it functions as a Lens

9 Positive Lens: Incident ray experiences a
gradually increment in refractive index from the border to center Negative Lens: Incident ray experiences a Gradually decrement in refractive index from the border to center

10 Types of LC Lenses Larger than 1mm aperture Smaller than 1mm aperture
Pico Projectors Cell Phones Screen Endoscopic Systems Ophthalmic Lenses Smaller than 1mm aperture Micro-lens arrays Optical Communication Lab on a Chip Switchable 2D/3D displays

11 Real-Time Liquid Crystal Fabrication
By: University of Central Florida (At Optical Society of America in 2007) Put a drop of photosensitive polymer on the top of the substrate Turn the substrate up-side down Coat a conductive polymer layer as electrode Flatten the lens surface by the same polymer

12 Photosensitive polymer is NOA81 (Norland Optical Adhesive), Ref
***Photosensitive polymer is NOA81 (Norland Optical Adhesive), Ref. Index = 1.52

13 Observation of interference rings of lens cell using a microscope
Sample was placed between two Cross polarizers The rubbing direction of the lens cell was oriented at 45°

14

15 Conventional vs LC

16 Advantages of LC Lenses
Tunable Focusing Low Power Consumption Compact Structure Good Stability Simple Fabrication Voltage Actuation Planar Simple Structure

17 Disadvantages of LC Lenses
Polarization Dependent Slow Response Time

18 References: 1. https://lcp.elis.ugent.be/tutorials/lc/lc1
2. Liquid crystal lens with large focal length tunability and low operating voltage Hongwen Ren, David W. Fox, Benjamin Wu, and Shin-Tson Wu College of Optics and Photonics, University of Central Florida, Orlando, Florida 32816 3. Micromachines 2014, 5, ; doi: /mi 4. An Electrically Tunable Liquid Crystal Lens for Fiber Coupling and Variable Optical Attenuation Michael Chen, Chyong-Hua Chen, Yin-Chieh Lai, and Yi-Hsin Lin* Department of Photonics, National Chiao Tung University, Hsinchu, 30010, R O C, Taiwan 5. Liquid Crystal Lens for Focusing and Zooming Systems Dr. Susumu SATO (Akita Prefectural R & D Center )


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