Determination of Verdet Constants of Organic Laser Dyes in Ethanol

Organic laser dyes are indespensible for dye lasers which are used to obtain unpolarized and polarized light. Verdet constant is a measure of the amount of~rotation of polarization direction of light under the application of an external magnetic field. We have measured Verdet constants of various laser dyes diluted in ethanol as a function of concentration. The Verdet constants approached that of ethanol with dilution but with a small upward systematic shift of 0.15 rad/Tm above the value measured for ethanol which is 2.85 rad/Tm. The reason for the upward systematic error is due to our reuse of the glass cells for different dyes, which in turn left a residue on the walls of the cell which we could not totally remove. This upward systematic shift is used to correct the measured values.