This paper presents the light transmission efficiency of metal–semiconductor–metal photo-detectors (MSM-PDs) using finite difference time-domain method. The absorption of MSM PDs can be enhanced with the aid of nano-grating coupled surface plasmon resonances at the design wavelength. The simulated results show that the light absorption
enhancement of nano-grating assisted MSM-PD is ∼9-times better than the conventional MSM-PD.