An optical package includes a substrate, an image sensor, a microlens, an optical filter layer, a constraining layer, and a buffer layer. The image sensor is disposed on the substrate. The microlens having a first Young's modulus is disposed on the image sensor. The optical filter layer having a second Young's modulus disposed on the microlens. The constraining layer is disposed between the optical filter layer and the microlens. The buffer layer having a third Young's modulus disposed on the constraining layer. The third Young's modulus is greater than the first Young's modulus and smaller than the second Young's modulus.