METHOD AND APPARATUS FOR STABILIZING LASER FREQUENCY USING ELECTROMAGNETICALLY INDUCED TRANSPARENCY

摘要

The present invention relates to a method and apparatus for locking an electromagnetic inductive transmission (EIT) signal to an atomic transition line using optical or electrical feedback techniques. Laser frequency stabilization method using electromagnetic induction permeability according to the present invention is a frequency-modulated linearly polarized coupled laser beam emitted by the coupling laser to lock the coupling transition line, the irradiation laser emits a linearly polarized irradiation laser beam, the The combined laser beam and the irradiation laser beam overlap each other and proceed in the same direction, and the irradiation laser beam and the combined laser beam are incident on a medium having at least three energy levels, thereby causing an EIT phenomenon to occur. And separating the irradiated laser beam transmitted through the medium and the combined laser beam, and optically feeding the separated irradiated laser beam to an irradiated laser by a diffraction grating, or using an optical detector, a lock-in amplifier, and a proportional integral controller. Electrical feedback. According to this method, the line width of the laser can be reduced than the natural line width, and thus the frequency stability is improved as compared with the conventional saturated absorption spectroscopy, which is limited by the natural line width.;Frequency Stabilization, EIT, Rubidium Cell, Optical Feedback, Electrical Feedback