We have demonstrated a high-performance two-wavelength asymmetric Fabry-Perot modulator (AFPM) by using a novel decoupled cavity design. In this new design, the middle mirror supplies a back-mirror reflectivity for the short-wavelength modulator and, at the same time, a front-mirror reflectivity for the long-wavelength modulator. The front mirror is designed to be transparent at the long wavelength and reflective at the short wavelength to eliminate the interference between the two modulators. With this decoupled cavity design, we greatly simplified the matching requirement for the two cavities and obtain much more flexibility in the device design. Experimentally, we have demonstrated a two-wavelength modulator operated at 860 and 890 nm with operating voltages of 3.4 and 6.2 V and reflectivity changes of 62% and 44%, respectively.