부산대학교 도서관

Based on a laser locked to the cesium Fg = 4 → Fe = 5 closed transition, we present the results of an investigation of nonlinear magneto-optical rotation (NMOR) using an uncoated buffer-gas-free cesium cell at room temperature under a near zero magnetic field, which has a reversal rotation signal and optimum rotation slope of − 46 rad/mT. Meanwhile, a magnetometer which has a simple structure and is available for cardiac magnetic measurement is reported. The magnetometer has a sensitivity of 0.3 pT/Hz1/2, which is limited by the photon-shot noise. Using a model for the interactions of atoms and linearly polarized light with arbitrary intensity that we built, we analyze the influence of the laser intensity on the linear dichroism of polarized atoms and the slope of the NMOR. The result of our theoretical analysis agrees with the experimental data. We also demonstrate that the intensity relative to zero slope is much less than the saturation intensity of the transition, because the rotation derives from the superposition of alignment precessions of Fg = 4 → Fe = 4,5 transitions and because the Fe = 5 state has a greater gyromagnetic ratio and total quantum number than Fg = 4 state does.