Patent attributes
A low-cost spinel sintered body having small polarization and high heat-conductivity is provided. Also, a useful light-transmitting window and light-transmitting lens for light-emitting device is provided. For such purpose, the spinel sintered body of the present invention has a contrast ratio of 300 or more in the case of white light, where the contrast ratio is defined as the quotient obtained by dividing an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being parallel to each other, by an amount of transmitting light in the case of being arranged between two polarizing plates, the polarizing directions of the two polarizing plates being orthogonal to each other.
