The present disclosure relates to an optical amplifier configured for an image capturing device. The optical amplifier may include a substrate. The optical amplifier may also include an optical amplification region formed over the substrate. The optical amplification region may include a first optical amplification layer and a second optical amplification layer. The first optical amplification layer may be configured to amplify light at a first wavelength range, and the second optical amplification layer may be configured to amplify light at a second wavelength range. The optical amplifier may further include at least one electrode layer electrically contacting the optical amplification region.