Multi-V-type and Λ-type electromagnetically induced transparency experiments in rubidium atoms with low-power low-cost free running single mode diode lasers

In this work we present the experimental realization of electromagnetically induced transparency (EIT) in A-type and multi-V-type configurations in a sample of rubidium atoms inside a vapor cell at room temperature. Typical EIT windows are clearly visible in the Doppler- broadened absorption signal of the weak probe beam. The coherent optical pump and probe fields are produced by two tunable low-cost, low-power, continuous-wave (cw), free-running and single mode operated diode laser systems, temperature stabilized and current controlled, tuned to the D2 line of rubidium atoms at 780.2 nm wavelength. The continuum wave and single mode operation of our laser systems are confirmed by direct and saturated absorption spectroscopy techniques. Among other applications, these simple experiments can be used as a low-cost undergraduate laboratory in atomic physics, laser physics, coherent light-atom interaction, and high resolution atomic spectroscopy.