The invention discloses an InGaAs
infrared polarization
detector based on a surface
plasma effect. The
detector comprises a substrate, a lower
doping layer, an absorbing layer, an upper
doping layer and a
metal grating layer, wherein the lower
doping layer, the adsorbing layer, the upper doping layer and the
metal grating layer are down-up successively deposited on the substrate. The
metal grating layer is a two-dimensional sub-
wavelength asymmetrically-structured grating, and used for receiving incident light
waves. The absorbing layer is used for absorbing light
waves. The upper doping layer and the lower doping layer are used for leading out two electrodes of the
infrared polarization
detector. According to the invention, by use of the two-dimensional sub-
wavelength asymmetrically-structured grating, the detector can be coupled to detected light
waves to stimulate the surface
plasma effect; through the surface
plasma effect, the light filed can be localized in the place near the metal and a
semiconductor, so efficiency of the detector can be improved; and the
electromagnetic vibration strengths generated under
irradiation of the incident light in different polarization directions of the asymmetric grating structure are different, so polarized
light detection can be achieved.