AMPLIFICATION OF OPTICAL-ROTATION BY A PASSIVE OPTICAL-SYSTEM

It is shown that the angle of optical rotation to be measured by a polarimeter can be amplified by means of a suitable located dichroic element. The technique increases the signal-to-flicker-noise ratio of an instrument. The increase observed here was sufficient to allow signals below 10(-3) degrees to be detected using ordinary dichroic sheet polarisers and a modulation frequency of 34 Hz.