Vertical forward coupler based channel-dropping photodetector

Abstract
We demonstrated an integrated channel-dropping photodetector in which a desired wavelength channel of the optical power is selectively coupled to a detector element. Based on a codirectionally grating-coupled GaAs/AlGaAs filter structure, a 1.2-nm-wide photocurrent response was obtained in an 800-nm-wavelength region with a device length shorter than 1 mm. Light passing through the device exhibited an alternate notch response, promising not to terminate the unselected channels.