Modelling
Physics 101 - Light
Light, or the visible light spectrum range from $\approx 400 - 800$nm in the electromagnetic radiation spectrum. Above (higher wavelengths) you will find infrared radiation, and under you will find the ultra violett radiation. Visible light, electromagnetic spectrum
Physics 101 - LED
Not monochromatic, circuite explanation
Physics 101 - Wavelength
The given wavelength $\lambda$ for a lightsource can be found by XX INSERT FORMULA HERE XX, by knowing the grid spacing, $d$ and angle, $\theta$.
Physics 101 - (Bio)laser
Mirrors, filters