Hilger & Watts Type Heavy Duty Michelson Interferometer

Main Features

• Heavy-Duty Construction: Designed for high-precision optical experiments.
• High-Quality Optics: Ensures sharp interference fringes.
• Fine Adjustment Mechanism: For precise control of mirror movement.
• Rigid Base and Housing: Minimizes vibrations and external disturbances.
• Beam-Splitting Optics: Produces two coherent beams for interference.
• Traveling Mirror System: Allows small path length variations for measuring wavelength differences.

Working Principle

The Michelson Interferometer works on the principle of wave interference:

1. Light from a monochromatic source (e.g., sodium lamp or laser) is split into two beams by a beam splitter.
2. One beam reflects off a fixed mirror, while the other reflects off a movable mirror.
3. The two reflected beams recombine at the beam splitter, creating an interference pattern.
4. The fringe pattern shifts when the movable mirror is adjusted, allowing measurements of wavelength, refractive index changes, or surface flatness.

Applications

1. Measurement of Wavelength ($\lambda$) of Monochromatic Light

   • By moving the adjustable mirror and counting fringe shifts, the wavelength can be calculated:

     λ=2dN\lambda = \frac{2d}{N}λ=N2d​

     where $d$ is the mirror displacement and $N$ is the number of fringes counted.

2. Refractive Index Measurement

   • Used to determine the refractive index ($n$) of gases or transparent materials by introducing them into one arm and observing the fringe shift.

3. Surface Flatness Testing

   • Used in precision engineering to check the flatness of optical components.

4. Determination of Small Displacements

   • Accurate to nanometer-level precision, making it useful in metrology and laser-based measurements.