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Young’s Double Slit


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All products are fully customizable including materials, please contact us with requests.


Named for Thomas Young’s classic proof of the wave theory of light in 1803. While Young’s original experiment used sunlight and calculated the average wavelength to be 550 nm, today using monochromatic and coherent light one can calculate wavelength with the following formula:

In which, λ is the wavelength of the light
d is the separation of the slits
n is the order of maximum observed (for first order n=1)
x is the distance between the bands of light and the central maximum (also called fringe distance)
L is the distance from the slits to the screen centerpoint

These elements may be used to demonstrate Young’s Interference Fringes, Michelson’s Stellar Interferometer (for measuring the separation between double stars) or other applications requiring measurement of the separation between point sources.

Contact us for Custom Quoted Slit Width and Spacing

9.5mm +0.025 / -0.050mm
(0.374in +0.000984 / -0.00197in)
Center Spacing
3 µm slits : 9 µm Spacing (Center to center)
50 µm slits : 150 µm Spacing (Center to Center)
100 µm slits : 300 µm Spacing (Center to Center)
Stainless Steel (SS-302/304) (50µm or 100µm)
Molybdenum (3µm)
Slit Tolerances


Tolerance +/-
3 µm
± 1µm
50 µm
± 5µm
100 µm+
± 10µm


Additional information

Slit Width

3µ ± 1 / 9µ Separation, 50µ ± 5 / 150µ Separation, 100µ ± 10 / 300µ Separation

The following prices are for online purchases and credit cards only.
Product Slit WidthSKUPrice
3µ ± 1 / 9µ SeparationY-SLIT-3/8-DISC-3USD 278.90
50µ ± 5 / 150µ SeparationY-SLIT-3/8-DISC-50USD 119.50
100µ ± 10 / 300µ SeparationY-SLIT-3/8-DISC-100USD 78.90
Product Slit WidthSKUPrice