Optical Atomic Sensors for Medical Applications

High precision diode laser based atomic magnetometers have been designed for measurement of magnetic field of the order of femtotesla. They have almost the same capability as SQUIDs, but they are much smaller in size and require no cryogenic facility. The high precision, sensitivity and reliability allow measurement of magnetic field of beating human heart. Such high precision measurement is possible by using Coherent Population Trapping (CPT) or Electromagnetically Induced Transparency (EIT) observed in atoms. Very small splitting produced by the small magnetic field can be measured. We shall discuss basic principle of observation of EIT in alkali atoms using two or more coherent diode lasers and measurement of narrow line structures. An international collaboration project is in process for development of cost effective miniaturized Coherent Optic Sensors for magnetocardiography. Like SQUID based instrumentation Optical Atomic Sensors will also provide non-invasive method of cardiac diagnosis. Ten different groups having expertise in laser spectroscopy, optics, electronics, biomagnetim and cardiography working in different parts of the world will participate in the endeavor. Some key features of the collaborative work will be presented.