FOL - MZM Mach Zehnder Interferometer

Optical Breadboard with Support
i) Dimensions: 800 mm × 600 mm
ii) Material: Stainless Steel
iii) Quantity: 1 No.
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Beamsplitter Mount
i) Degrees of Freedom: 2 degrees
ii) Material: Black anodized Aluminium alloy
iii) Quantity: 1 No.
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Mirror Mount with Precision Translation
i) Adjustment Range: ±3 degrees
ii) Material: Black anodized Aluminium alloy
iii) Least Count (Micrometer): 0.01 mm
iv) Quantity: 1 No.
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Screen with Mount
i) Dimension: 75 mm × 75 mm
ii) Quantity: 1 No.
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Mirror with Cell
i) Diameter: 25 mmThickness: 6 mm
ii) Material: Borofloat
iii) Coating: Aluminium
iv) Quantity: 2 Nos.
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Glass Slide
i) Dimensions: 75 mm × 25 mm
ii) Thickness: 1 mm
iii) Quantity: 5 Nos.
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Diode Laser with Power Supply (Green)
i) Wavelength: 532 nm
ii) Optical Power: 5 mW
iii) Quantity: 1 No.
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Kinematic Laser Mount
i) Material: Black anodized Aluminium alloy
ii) Adjustments: Using 80 TPI lead screws
iii) Adjustment Range: ±3 degrees
iv) Quantity: 1 No.
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Mirror Mount with Translation
i) Adjustment Range: ±3 degreesFine
ii) Adjustments: Using 80 TPI lead screws
iii) Material: Black anodized Aluminium alloy
iv) Quantity: 1 No.
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Rotation Stage
i) Resolution: 2° per division
ii) Material: Black anodized Aluminium alloy
iii) Quantity: 1 No.

Pressure Cell
i) Length: 10 cm
ii) Pressure Range: 0 – 300 mm Hg
iii) Quantity: 1 No.
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Beamsplitter
i) Dimensions: 50 mm × 50 mmThickness: 6 mmR/T
ii) Ratio: 50/50
iii) Material: N-BK7
iv) Coating: Aluminium
v) Quantity: 1 No.
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Diode Laser with Power Supply (Red)
i) Wavelength: 650 nm
ii) Optical Power: 5 mW
iii) Quantity: 1 No.

1) To determine wavelength of laser beam.
The wavelength of laser is calculated by,
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λ = (2d / N) Δ

where ‘d’ is the change in position that occurs for ‘N’ fringes to pass and Δ is the calibration constant of the micrometer.

2) To find refractive index of a transparent material.
The light passes through a greater length of glass as the plate is rotated. The change in the path length of the light beam as the glass plate is rotated relates the change in path length with the laser beam through air.
The refractive index of glass slide,
N = (2t − Nλ) (1 − cosθ) / [2t (1 − cosθ) − Nλ]
Where t is the thickness of the glass slide, N is the number of fringes counted, λ is the wavelength of light used and θ is the angle turned for N fringes.

3) To study refractive index change in air under different pressures and determine refractive index of air.
When a piece of material of thickness d is placed in one arm of the interferometer, the change in optical path length is given by 2d(n − 1), where n is the difference in refractive index between the sample and the material it replaced (usually air). In other words, 2d(n − nair) / λ extra wavelengths are introduced if air is replaced by a sample of refractive index n.