What light does on its way to us: mirrors and lenses, the images they make and the faults they cannot avoid, the instruments built from them, the colour of things and of the sky, interference, diffraction and holograms, polarisation, the laser and its beam, the fibre, the detector and the chip, and light that comes one photon at a time. Trace every ray, watch every wave and measure every beam on the page.
Never look at the sun through any optic, and never point a laser at a person, an animal, a vehicle or an aircraft. Every ray, wave, spectrum and beam on these pages is computed by the page; your progress stays in this browser. Not affiliated with or endorsed by any standards body, manufacturer or organisation mentioned here; trade names and glass designations belong to their owners. No eye-care or medical advice is given.