Using the bench
The light source
Every bench has exactly one source. Everything downstream depends on how you set it up, so it is worth knowing all of it.
Type
| Type | Emits | Use for |
|---|---|---|
| Laser | A perfectly collimated beam of a set width | Almost everything — lenses, prisms, interference |
| Area | A collimated beam from a finite-sized emitter | Extended sources, softer illumination |
| Point | A diverging cone of a set half-angle | Imaging, projection, anything where light spreads from a point |
Spectrum and wavelength
Mono traces one wavelength you pick; RGB traces 640, 532 and 450 nm; White traces 24 wavelengths across the visible band. More wavelengths cost more compute but give real dispersion.
Beam shape
| Field | Means |
|---|---|
| Beam width | Diameter of the collimated beam, in mm (laser and area) |
| Cone half-angle | How fast a point source diverges, in degrees |
| Beam lines | How many rays are drawn across the beam. More lines means a smoother-looking fan; it does not change the physics |
Power and brightness
Power in mW is the physical quantity: it sets what the detector reports in milliwatts and W/cm². Brightness only affects how bright the beam looks on screen. Changing brightness never changes a measurement.
Polarisation
Unpolarised, linear (with an angle measured from horizontal), or right/left circular. Rolling the source with V / B rotates its linear polarisation with it, exactly as turning a real laser on its mount would.
Placing it
The source starts at x = 0, beam height y = 100 mm, firing along +x. Move and rotate it like any other part — pitch it up with R and the whole experiment tilts with it, because new parts and auto-placed screens follow the beam.