Optics Area

Geometrical Optics

Topic 69 demos

Three-panel image: (left) Mini Maglite with wooden bar casting a sharp shadow on the wall, (center) round frosted bulb with the same bar casting a diffuse shadow, (right) tall clear filament bulb with the bar held horizontally

Shadows

Students observe how source geometry determines shadow sharpness. A point source (Mini Maglite) casts sharp shadows; an extended source (frosted bulb) produces penumbra. A tall clear filament bulb shows orientation-dependent …

White optics board with ray projector at left edge projecting a single ray that reflects off a black plane mirror mounted magnetically on the board

Blackboard Optics Plane Mirrors

Visible light rays reflect off plane mirrors on the blackboard optics board, demonstrating. Mirrors can be combined to build periscopes, corner reflectors, and other multi-mirror systems.

Green laser pointer mounted in a clamp on a blue stand, aimed at a flat mirror lying on the table; green incident and reflected beams form an X pattern on the mirror surface; fog machine with red button visible behind the mirror

Laser and Mirror

A green laser aimed at a flat mirror demonstrates the law of reflection . Fog or chalk dust makes the incident and reflected beam paths visible, giving students direct visual …

Photometry

Topic 3 demos

Cuda I-150 fiber optic light source on left, small square barrier on a clamp mounted on an optical rail, green gridded chalkboard in background — barrier at maximum distance, no visible shadow

Inverse Square Law

A point light source casts the shadow of a small square barrier onto a gridded board. Each time the barrier-to-source distance is halved, the shadow area quadruples — directly visualizing …

Two cardboard boxes of different sizes with dark paper roofs and white block "chimneys," each with a black paper panel on the front containing a circular aperture that appears identically black

Blackbody Boxes

Two boxes with different interior colors (white vs. black) show identical black apertures when closed, demonstrating that a cavity with a small opening approximates an ideal blackbody regardless of interior …

Red, green, and blue square glass filters mounted vertically in lens holders on a ring stand, all brightly illuminated by an incandescent bulb behind them at full power

Color and Temperature

Shows how a blackbody spectrum shifts with temperature by varying the voltage to an incandescent bulb viewed through red, green, and blue filters. As voltage decreases, blue disappears first, then …

Diffraction

Topic 8 demos

$Four green laser single-slit diffraction patterns stacked vertically, from widest slit (top, narrow pattern) to narrowest slit (bottom, wide pattern with many visible side maxima)$

Electroformed Single Slits

Students observe single-slit Fraunhofer diffraction patterns produced by a laser through precision electroformed slits of different widths. Comparing the patterns demonstrates the inverse relationship between slit width and diffraction pattern …

$Green laser and Cornell diffraction plate mounted on optical rail, with single-slit diffraction pattern projected on white paper attached magnetically to the blackboard$

Cornell Plate Single-Slit Diffraction

Demonstrates single-slit Fraunhofer diffraction using a Cornell plate with calibrated slits of varying widths. Students observe the inverse relationship between slit width and diffraction pattern width, with quantitative verification possible …

$Green laser and PASCO diffraction wheel mounted on optical rail sliders, projecting a single-slit diffraction pattern onto white paper attached to the blackboard$

Variable Single Slit

Demonstrates single-slit Fraunhofer diffraction and the inverse relationship between slit width and angular spread. Students directly observe that narrower slits produce wider diffraction patterns by rotating through discrete slits from …

Interference

Topic 17 demos

$Four horizontal rows of green double-slit interference patterns on a dark background, each showing different fringe spacings and diffraction envelopes corresponding to the four slit configurations$

Electroformed Two-Slit Interference

Laser light through precision double slits produces interference patterns that demonstrate the wave nature of light. Four slit configurations allow direct comparison of how slit width and spacing affect fringe …

Green laser passing through Cornell plate mounted on ring stand with finger clamp, producing a horizontal interference pattern on white paper magnetically attached to blackboard

Cornell Plate Double-Slit Interference

A laser illuminates double slits on a Cornell plate, producing an interference pattern on a distant screen. The Cornell plate has multiple slit configurations (varying separation, width, and number of …

$Green laser and PASCO diffraction wheel mounted on optical rail with optical sliders, projecting a faint green interference pattern onto white paper magneted to blackboard$

Variable Double Slit

Demonstrates double-slit interference with variable slit separation using a laser and PASCO diffraction wheel. Students observe the inverse relationship between slit separation and fringe spacing, providing direct verification of.

Color

Topic 14 demos

Colored shadows on a projection screen showing three overlapping circles in yellow, cyan, and magenta, with secondary overlaps in red, green, and blue, and a dark center where all three shadows overlap

Primary Color Floodlights

Demonstrates additive color mixing using red, green, and blue floodlights. Students observe that overlapping primary-colored lights produce secondary colors (cyan, magenta, yellow) and white, contrasting with the subtractive mixing they …

Two flood lamps with reflective metal housings aimed at a white board, with a circular barrier held on a stick creating overlapping blue and red-orange colored shadows on the screen

Colored Shadows

Students observe that light travels in straight lines by blocking one of two colored light sources and predicting the resulting shadow colors. The demo builds from simple ray tracing to …

Long-exposure photo of the word 'light' written in cursive with the Rav'n light, showing continuous RGB-striped trails with no gaps between colors

Tri-Color LED Color Mixing

Tri-color LEDs that appear white when stationary reveal separated red, green, and blue pulses when swung rapidly through the air. Students see that white light can be synthesized from three …

Polarization

Topic 17 demos

Overhead projector with black mask taped to the stage using blue tape, a polaroid sheet on the mask, and a ring stand with ring holding a second polaroid above the projection surface

Polaroid Sheets

Polaroid sheets on an overhead projector demonstrate Malus's Law and the three-polarizer paradox. Students observe crossed polarizers blocking light, then see that inserting a third polarizer at 45° between them …

Two wooden polarization grids clamped to a green-topped lecture bench with yellow rubber tube threaded through — one grid has horizontal bars, the other has vertical bars

Polarized Waves

Transverse waves on a rubber tube pass through or are blocked by wooden grids, providing a mechanical analogy for light polarization. Students see single-polarizer transmission, crossed-polarizer extinction, and the surprising …

Giant metal Slinky stretched along a green demo bench with three lead bricks forming a tunnel barrier — two bricks side by side with a third across the top

Polarization: Transverse vs. Longitudinal

Uses a giant Slinky and lead brick barrier to show that transverse waves can be polarized (blocked) while longitudinal waves pass through unimpeded. Provides a mechanical analogy for how polarizing …

The Eye

Topic 9 demos

Assembled anatomical eye model on wooden base with numbered components, white sclera, red extraocular muscles, tan lacrimal gland at rear, and transparent cornea showing iris and pupil

Eye Model

Anatomical eye model with removable components (lens, iris, vitreous body) for teaching the eye as a compound optical system. Students connect physical structures to their optical functions: corneal refraction, accommodation, …

Blackboard optics eye model on sketch paper: ray projector on left sends parallel light rays through plexiglass lenses in a double holder, with a black BNC cable forming an eye outline. Rays converge at the focal point marked by blue tape on the cable. Rays continue diverging past the focal point showing slight chromatic dispersion.

Blackboard Optics Eye Model

Models the optics of the human eye on a blackboard using magnetic plexiglass lenses and ray projectors. Students observe normal vision, myopia, and hyperopia by swapping lens combinations, and see …

Lecture hall triple chalkboards with ABCD reference card on far left and individual colored letter cards (A, B, C, D) magneted at intervals across the boards

Blind Spot

Students locate their visual blind spot--the region where the optic nerve exits the retina with no photoreceptors. Demonstrates that the brain actively fills in missing visual information rather than passively …

Modern Optics

Topic 1 demo

Green laser on wooden stand illuminating a holographic plate, projecting a large holographic image of a telephone onto the wall in a darkened room

Projection Holograms

Demonstrates holographic image projection using laser illumination of transmission holograms. Students see how holograms encode amplitude and phase information, and how illuminating different portions of the plate reconstructs different viewing …