Coherent population trapping detector

摘要

A CPT detectorÄ200Ü and a method for detecting CPT are disclosed. The CPT detectorÄ200Ü includes a quantum absorberÄ204Ü, a polarization analyzerÄ206Ü, and a detectorÄ208Ü for generating a signal. The quantum absorberÄ204Ü includes a material having first and second low energy states coupled to a common high energy state. Transitions between the first low energy state and the common high energy state and between the second low energy state and the common high energy state are induced by electromagnetic radiation having a predetermined polarization state. The polarization analyzerÄ206Ü blocks electromagnetic radiation of the predetermined polarization while passing electromagnetic radiation having a polarization state that is orthogonal to the predetermined polarization. The polarization analyzerÄ206Ü is irradiated with a portion of the generated electromagnetic radiation that has passed through the quantum absorberÄ204Ü. The detectorÄ208Ü generates a signal related to the intensity of electromagnetic radiation that leaves the polarization analyzerÄ206Ü. <IMAGE>