The resonant tunneling effect is optically enhanced in a GaAs/GaAlAs double‐barrier structure that has partial lateral current confinement. The peak current increases and the valley current decreases simultaneously when the device surface is illuminated, due to the increased conductivity of the top layer of the structure. The effect of the lateral current confinement on the current‐voltage characteristic of a double‐barrier resonant tunneling structure was also studied. With increased lateral current confinement, the peak and valley current decrease at a different rate such that the current peak‐to‐valley ratio increases up to three times. The experimental results are explained by solving the electrostatic potential distribution in the structure using a simple three‐layer model.