Red diode laser light passing through dextrose and d-fructose (Karo syrup).
The laser light is coming from the top. It is linearly polarized and the polarization direction rotates as the beam moves down through the syrup. Scattered light at right angle to the vertical beam is polarized horizontally. When the beam polarization points towards the camera no horizontal component is available and no scattering can occur; a dark "node" is observed. |