Input data
Distance from the prism to the screen.
Positive or negative may be used to indicate the direction.
Example: BK7 ≈ 1.5168 at 587.6 nm.
Calculated values
Prism apex angle A
—
Enter the input data and press Calculate.
Beam deviation δ
—
Enter the input data and press Calculate.
Thin-prism approximation:
—
Calculation model
Beam deviation from the screen displacement
δ = atan(Δx / L)
Exact prism relation used by the calculator
δ = asin(n · sin A) − A
Assumption:
the incident laser beam is normal to the first prism surface.
The calculated angle A is therefore the prism apex angle
corresponding to the measured beam deviation.
The thin-prism approximation
A ≈ δ / (n − 1) is also displayed for comparison.