Various embodiments of a photonic device and fabrication method thereof are described herein. A device may include a substrate, a bottom contact layer, a current confinement layer, an intrinsic layer, an absorption layer, and a top contact layer. The bottom contact layer may be of a first polarity and may be disposed on the substrate. The current confinement layer may be disposed on the bottom contact layer. The intrinsic layer may be disposed on the current confinement layer. The absorption layer may be disposed on the intrinsic layer. The top contact layer may be of a second polarity and may be disposed on the absorption layer. The second polarity is opposite to the first polarity.