Summary form only given. We demonstrate the resonant-cavity-enhanced effect by placing microwave detectors in a layer-by-layer photonic crystal. We used the output of a network analyzer as the microwave source, and fed the output to a horn antenna to obtain EM waves. The crystal was then replaced in the beam-path of the EM wave, and the electric field inside the cavity was measured by a probe that consisted of a monopole antenna. The output of the antenna was measured by use of two different techniques: network analyzer and microwave detector within the cavity. The first cavity structure was similar to a one-dimensional Fabry-Perot resonator made of two mirrors separated by a distance.