Demonstration of double EIT using coupled harmonic oscillators and RLC circuits

Single and double electromagnetically induced transparency (EIT) in a medium,\nconsisting of four-level atoms in the inverted-Y configuration, are discussed\nusing mechanical and electrical analogies. A three coupled spring-mass system\nsubject to damping and driven by an external force is used to represent the\nfour-level atom mechanically. The equations of motion of this system are solved\nanalytically, which revealed single and double EIT. On the other hand, three\ncoupled RLC circuits are used, as the electrical analog, to explore and\nexperimentally demonstrate single and double EIT. The simplicity of these two\nmodels makes this experiment appropriate for undergraduate students and easy to\nincorporate into a college physics laboratory.\n