Controlled Photonic Stop Bands in a Four-Level Atomic System of an Inhomogeneously Broad-End Solid

A neatly controllable photonic band gap formed in a four-level tripod system in the solid material, Pr³⁺-doped yttrium orthosilicate (Pr:YSO) is investigated. Driven by two standing waves, the sample is just like a photonic crystal to the weak probe. Based on the numerical simulation and the analytic result we present a clear and full-scale view on the induced band gap in the inhomogeneously broadened tripod system.