Patent attributes
An optical transmitter-receiver module has a structure in which a light-emitting device and a light-receiving device are coupled with an optical fiber through a wavelength-selecting filter. In the above structure, part of the lightwave of the light-emitting device is reflected from the wavelength-selecting filter, is reflected again from a wall in the opposite direction, and enters the light-receiving device, causing optical crosstalk between the light-emitting device and the light-receiving device. An object of the invention is to prevent the crosstalk between the light-emitting device and the light-receiving device. An inverted conical hole is provided in a wall at which the lightwave of the light-emitting device arrives after it is reflected from the wavelength selecting filter. The hole has a size larger than the spread of the reflected lightwave of the light-emitting device. The hole has a vertical angle of 72 to 80 degrees or 100 to 160 degrees.
