MVLscope

TINY WORLD / STRIPES INTO SHAPE

Fringe Climber

Catch the stripes

Two terraces. Which one sits higher?

SIMULATED · OPTICAL PROFILOMETRY

Follow the bands

Schematic fringe view · bands exaggerated for visibility

18.0
0 · Lower100 · Higher

Move through the scan height. Keep a view when a terrace’s stripes look clearest.

Optional scientific referencesExplore the microscopy labs ↗

Preparing the terraces…

YOUR FIRST CLIMB

Watch the stripes stand out.

  1. Move the scan slider, or choose Scan upward.
  2. When a terrace’s light and dark stripes look clearest, pause. Select its letter and press Keep view.
  3. Do that for each terrace. Compare the saved scan positions, then arrange the letters from lowest to highest.

In this model, terraces that reach their clearest bands later in an upward scan are higher. One bright stripe alone is not enough. You can rescan and change your answer without a penalty.

How does an optical head turn light into a height clue?

Two returning paths. One interference signal.

Light returning from the sample combines with light returning from a reference surface. A scan changes their relative optical path. The rise and fall of fringe contrast helps locate a surface; a single bright stripe repeats during the scan.

Illustrative optical profiler head over a sample, with a reference path and sample path.
Illustrative optical head. The optional 3D view unfolds a mint sample route and purple reference route to explain the principle. These are not a real instrument's optical layout, path lengths or motor direction.

Optional interactive diagram. The activity keeps your evidence.

  1. 1 · Split and returnThe reference and sample paths return light to the optical head.
  2. 2 · Combine at the cameraThe returning light produces interference. Bright and dark bands depend on phase.
  3. 3 · Follow the contrastThe game asks where light and dark bands differ most as its scan coordinate increases.

SEPARATE TEACHING EXAMPLE

Contrast grows once. Brightness repeats.

This invented surface is fixed at 58 game units. It is separate from every terrace in your climb. Move this example's scan to compare band contrast with the brightness of one fixed pixel.

The existing fringe image model, on a separate teaching surface.
Band contrastOne pixel's brightness

Both curves come from the existing pixel model. Brightness is one pixel's gray value divided by 255; contrast compares the light and dark bands. The diagonal bands and envelope are schematic. All lengths here are relative game units, not nanometres. Increasing the coordinate is not a motor instruction.

NIST background on interference microscopy ↗

ABOUT THIS SIMULATION

Finding height with interference.

This game is inspired by coherence scanning interferometry, an optical-profilometry method. A scan records interference signals over a range of positions. Their contrast envelope helps locate a surface; real instruments can also use phase information.

These are invented flat terraces and original grayscale teaching images. A Gaussian contrast envelope is combined with a repeating phase term. The diagonal bands are a schematic display aid, not a complete tilted-reference optical model. Patch boundaries stay sharp: this is not a focus-blur puzzle. There is no calibrated physical scale.

“Upward” means increasing this game’s scan coordinate. It is not an instruction about a real instrument’s motor direction. All lengths are relative game units. Bright and dark phase cycles repeat, so one stripe does not establish the unrestricted height. The game asks for height order using clear saved views; it does not demand one exact slider value.

Real metrology requires calibration and more complete processing. This model omits high-NA imaging, sample slope effects, reflectivity differences, noise, dispersion, multiple reflections and many instrument errors. The final profile is the known invented model, not a reconstruction from your saved views.

The automatic sweep is optional and simplified. Text descriptions provide an alternative way to examine band contrast without penalty. Your progress lasts while this page is open. These are exploratory puzzles, not a skills test or instrument procedure.

Scientific background and model details

Start a fresh set of climbs?

This clears the saved views and current progress.