Introduction
This science experiment has two objectives. The first one is to design an optical instrument that polarizes light based on the selective subtraction theory. This instrument will be designed in such a way that it could be used as a platform for recording polarizing holographic optical elements. The second one includes the manipulation of holographic optical elements such that it polarizes specific wavelengths of light, scattering and absorbing all others.
Aim
To design an optical instrument that polarizes light based on the selective subtraction theory and to chemically manipulate the holographic optical element such that it polarizes specific wavelengths of light.
Theory
1. The electric field propagating in free space is perpendicular to the direction of propagation of light.
2. A light is linearly polarized along a fixed direction if the electric field remains parallel to that direction as time passes.
3. This is also called plane-polarized light.
4. A light is called unpolarized when the electric fields have different directions and keep changing with respect to time. For example, an electric lamp, a candle, the sun, a mercury tube, etc.
5. According to Brewster’s law, the maximum polarization can be achieved when the refracted ray of a transparent medium makes an angle of 90 degrees with the reflected ray of that medium.
Requirements
2. Standard Holographic Recording Material
3. Isolated Platform
4. Optical Mounts
5. A Helium-Neon Laser
6. Glass Substrates
7. High Resolution silver-halide holographic emulsion on polymer
Procedure
Step 1: Construct a glass-plate polariser to accomplish the first objective.
Step 2: Design the desired optical system using a method which is called selective subtraction via a glass-plate polarizer.
Step 3: This optical system consists of standard holographic recording materials, which include an isolated platform, a helium-neon laser, optical mounts, processing chemistry, and a high-resolution silver-halide holographic emulsion on polymer and glass substrate.
Step 4: Now, for the second objective, press well the holographic emulsion in a method called Presensitization.
Step 5: Record your observations.
Observation
From the experiment, we observed that using Brewster’s law, the polariser eliminated light that has undesired polarization.
For the second objective, we used Presensitization, which utilizes the chemical triethanolamine (TEA), which gets absorbed into the emulsion and decides the reconstruction frequency of the holographic optical element.
Results
1. We determined that on the basis of the state of polarization and initial wavelength of light, the utilized experimental method was the effective and innovative way to polarize it.
2. The polarizing holography optical element performed no less than the current polarizing technology.
VIVA Questions With Answers
Q.1 What was the aim of your experiment?
ANS. To design an optical instrument that polarizes light based on the selective subtraction theory and to chemically manipulate the holographic optical element such that it polarizes specific wavelengths of light.
Q.2 What do you understand about plane-polarized light?
ANS. A light is linearly polarized along a fixed direction if the electric field remains parallel to that direction as time passes. This is also called plane-polarized light.
Q.3 What do you understand about unpolarised light?
ANS. Light is called unpolarized when the electric fields have different directions and keep changing with respect to time.
Q.4 Give some examples of unpolarised light.
ANS. An electric lamp, a candle, the sun, a mercury tube, etc.
Q.5 What is Brewster’s law?
ANS. According to Brewster’s law, the maximum polarization can be achieved when the refracted ray of a transparent medium makes an angle of 90 degrees with the reflected ray of that medium.
Saquib Siddiqui is a Mechanical Engineer and a content creator. He has special interest in science experiments and teaches the same to school and college students. He is also a technical lead at RUDE LABS PVT. LTD.
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