Quick Answer: Optical Plane Glass Slab is a rectangular glass slab with two parallel plane faces for showing refraction and the sideways shift of a ray that leaves parallel to its incident direction.
Last updated: October 2026
Key Features
Rectangular slab with opposite parallel plane faces
Glass construction
Demonstrates lateral displacement of a light ray
Works with pins, a ray box or another narrow-beam source; the slab needs no power
Technical Specifications
Specification
Value
Shape
Rectangular, opposite parallel plane faces
Material
Glass
Power
None for the slab
About This Product
Students trace the slab's outline on paper, send a ray in at an oblique angle, mark where it enters and leaves, then join the points to show the refracted path and measure the sideways shift. It suits Light And Optics exercises on Snell's law, parallel-sided media and refractive index.
Frequently Asked Questions
Q1. Why does a ray shift sideways through the slab? It bends at both parallel faces and emerges parallel to its original direction, but from a laterally displaced position.
Q2. What affects the size of the lateral displacement? Slab thickness, the angle of incidence and the refractive index of the glass relative to the surrounding medium.
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