A recently developed solid‐state‐laser‐simulated tuning technique has been used to investigate the coincidence of Er : YAG laser emission with methane (CH4) gas absorption in the 1.6‐&mgr;m region. When the laser is operated under maximum‐bandwidth conditions, full coincidence is obtained, thus enabling possible remote sensing of CH4in the eye‐safe region. Unresolved fine structure of the CH4absorption line was indicated.