We report a near infrared photodetector that is able to detect different wavelengths by actuating a tilting mirror. The photodetection is based on a Schottky junction and the surface plasmon decay on an Au grating. The titling mirror changes the incident angle to couple light with specific wavelength to surface plasmon. In this paper, we confirmed that the grating of the proposed photodetector can couple different wavelength lights, and measured the mechanical deflection of the tilting mirror.