System for measuring optical activity of materials

Claim 1

IN A POLARIMETER: POLARIZATION-SENSITIVE MEANS INCLUDING A PHOTOSENSITIVE DEVICE AND HAVING A POLARIZATION AXIS ASSOCIATED THEREWITH; A SOURCE OF RADIATION ENERGIZABLE FROM A POWER SOURCE OF ALTERNATING CURRENT OF FUNDAMENTAL FREQUENCY; MEANS FOR TRANSMITTING FROM SAID RADIATION SOURCE ALONG AN OPTICAL PATH TO SAID POLARIZATION-SENSITIVE MEANS A PLANE-POLARIZED BEAM OF RADIATION, SAID PHOTOSENSITIVE MEANS RESPONDING TO RADIATION REACHING SAID POLARIZATION-SENSITIVE MEANS TO PRODUCE AN ELECTRIC SIGNAL HAVING A MAGNITUDE THAT CORRESPONDS TO THE MAGNITUDE OF THE COMPONENT OF THE POLARIZED RADIATION THAT IS POLARIZED IN A DIRECTION PARALLEL TO SAID POLARIZATION AXIS; OPTICAL ROTATION PRODUCING MEANS LOCATED ON SAID PATH FOR ROTATING THE PLANE OF POLARIZATION OF SAID BEAM; MEANS FOR LOCATING ON SAID PATH A SAMPLE HAVING A POLARIZATION PROPERTY SUCH THAT THE SAMPLE ROTATES THE PLANE OF POLARIZATION OF SAID TRANSMITTED RADIATION AS IT IS TRANSMITTED; MEANS ACTING ON SAID OPTICAL ROTATION PRODUCING MEANS TO OSCILLATE THE PLANE OF POLARIZATION OF SAID RADIATION ABOUT A POSITION CROSSED RELATIVE TO SAID POLARIZATION AXIS AT SAID FUNDAMENTAL FREQUENCY, WHEREBY AN ALTERNATING ELECTRIC SIGNAL IS DEVELOPED BY SAID PHOTOSENSITIVE DEVICE AT SAID FUNDAMENTAL FREQUENCY; MEANS SELECTIVELY RESPONSIVE TO THE FUNDAMENTAL COMPONENT OF SAID ALTERNATING ELECTRIC SIGNAL FOR DEVELOPING AN OUTPUT SIGNAL HAVING A MAGNITUDE THAT CORRESPONDS TO THE AMPLITUDE OF SAID FUNDAMENTAL COMPONENT OF SAID ALTERNATING ELECTRIC SIGNAL FOR INDICATING THE AMOUNT OF ROTATION OF THE PLANE OF POLARIZATION OF SUCH RADIATION PRODUCED BY SUCH SAMPLE; AND RECTIFIER MEANS SUPPLYING DIRECT CURRENT FROM SAID POWER SOURCE OF SAID RADIATION SOURCE, SAID RECTIFIER MEANS COMPRISING AN ELECTRIC FILTER CONNECTED TO SAID RADIATION SOURCE FOR ATTENUATING ALTERNATING CURRENT COMPONENTS HAVING A FREQUENCY HALF THE FUNDAMENTAL FREQUENCY THAT IS SUPPLIED FROM SAID POWER SOURCE.