Patent ID: 7031587

Claim:
A waveguide type photoreceptor device comprising: a semi-insulative semiconductor substrate; and an optical waveguide layer connected between first and second electrodes and disposed on said semiconductor substrate, having a first cladding layer of a first conductive type, a first light guide layer of the first conductive type, a light absorption layer, a second light guide layer of a second conductive type, and a second cladding layer of the second conductive type laminated onto one another over said semiconductor substrate in that order, wherein the ratio of the layer thickness of the thicker one of the first light guide layer and the second guide layer to that of the thinner one is between 1.3 and 5 both inclusive, wherein the composition wavelength of the first light guide layer and the second light guide layer is less than 1.3 μm and longer than that of the first cladding layer and second cladding layer, and wherein the sum of the layer thickness of the first light guide layer and the second light guide layer is set to any value between 0.9 and 1.2 μm.