How to use the single slit diffraction calculator
Find angle and position of the first dark fringe. Enter wavelength, slit width, screen distance in the fields above; the first minimum angle, first minimum position are computed instantly and plotted on the chart so you can see how the answer changes.
Formula
Variables
- lam — Wavelength (nm)
- a — Slit width (µm)
- L — Screen distance (m)
Worked example
With wavelength = 633 nm, slit width = 50 µm, screen distance = 2 m, the calculator gives first minimum angle ≈ 0.7253839 °; first minimum position ≈ 25.32203 mm.
Frequently asked questions
What is the formula for the single slit diffraction calculation?
First minimum angle (°) = asin(lam × 1e-9 / (a × 1e-6)). First minimum position (mm) = L × tan([First minimum angle]) × 1000. Here lam is wavelength (nm), a is slit width (µm), L is screen distance (m).
What inputs do I need for the single slit diffraction calculator?
You need wavelength in nm, slit width in µm, screen distance in m. Each field is pre-filled with a typical example so you can see how the result responds as you edit the numbers.
How do I use this calculator?
Type values into the input fields. Results and the chart update instantly. Use Reset to restore the example values, Copy results to paste them elsewhere, or Share to copy a link that preserves your inputs.
Is the result exact?
Calculations use standard formulas and double-precision arithmetic, then display about seven significant figures. Real-world measurements carry uncertainty, so treat results as estimates unless your inputs are exact.