Tunable metamorphic InGaAs partially depleted absorber photodiodes with resonant cavity enhanced structure are fabricated on GaAs substrate. Dark-current densities of 7.2 x 10(-7) A/cm(2) at 0 V and 3.6 x 10(-4) A/cm(2) at -5 V, a high quantum efficiency of 74.4 % at 1546 nm, and a 3-dB bandwidth up to 12 GHz are achieved. The full width at half maximum of the detector is about 16 nm. Furthermore, through thermal tuning, the peak wavelength red shifts from 1527nm to 1544 nm, and a tuning range o
