The Yoghurt Pot Polarimeter
More detailed instructions for the construction of this instrument can be found in this pdf.
Principle
This version of the polarimeter works on the fact that the screens of smartphones (and electronic devices in general) typically emit plane polarized light. This avoids the need for a second filter found in traditional polarimeters which is placed immediately after the light source and before the sample. The analyzer filter was one lens from a pair of 3D cinema spectacles (those that work on polarized light).
The use of the large yoghurt pot solves one of the main problems of home built polarimeters which is to have an accurate way for turning the analyzer filter because the large lid is clearly engineered to fit the body closely but not so close that it is impossible to rotate. Also, the rotation is quite positive with virtually no slippage.
Examples of how this polarimeter can be used can be found here:
Polarimeter - simple experiments that can be done with this polarimeter: rotation changes as a function of wavelrngth, measuring specific rotation of chiral molecules
Polarimeter - kinetics of sucrose inversion
Polarimeter - demonstration of Malus' law
Principle
This version of the polarimeter works on the fact that the screens of smartphones (and electronic devices in general) typically emit plane polarized light. This avoids the need for a second filter found in traditional polarimeters which is placed immediately after the light source and before the sample. The analyzer filter was one lens from a pair of 3D cinema spectacles (those that work on polarized light).
The use of the large yoghurt pot solves one of the main problems of home built polarimeters which is to have an accurate way for turning the analyzer filter because the large lid is clearly engineered to fit the body closely but not so close that it is impossible to rotate. Also, the rotation is quite positive with virtually no slippage.
Examples of how this polarimeter can be used can be found here:
Polarimeter - simple experiments that can be done with this polarimeter: rotation changes as a function of wavelrngth, measuring specific rotation of chiral molecules
Polarimeter - kinetics of sucrose inversion
Polarimeter - demonstration of Malus' law