Patent ID: 8395106

Claim:
An optical semiconductor device comprising: a polarization unit configured to control a polarization direction of an incident light to be measured; an active part, which includes a quantum dot having dimensions that differ from one another among directions, said active part to which the incident light, in which the polarization direction of the incident light is controlled, is applied, and said active part generates an electric signal by photoelectrically converting a light having a wavelength which differs corresponding to the polarization direction of the incident light; a read unit configured to read the electric signal generated by the active unit; and a control unit configured to read the electric signal by the read unit in synchronization with a control of the polarization direction by the polarization unit and detect respective intensities at plural wavelength bands of the incident light corresponding to the polarization direction of the incident light, wherein the polarization unit includes a polarizer which converts the incident light to a linearly polarized light, and a liquid crystal filter which changes a polarization direction of the linearly polarized light.