The utility model relates to the technical field of optical couplers, in particular to a
light guide structure of an
optical coupler. According to the technical scheme of the utility model, the
light guide member used for guiding the light emitted by the IR
chip to the light-sensitive surface of the PT
chip is arranged between the PT
chip and the IR chip, so that part of the light emitted by the IR chip can be efficiently guided to the light-sensitive surface of the PT chip, and the efficiency of transmitting the light of the IR chip to the light-sensitive surface of the PT chip as a whole can be improved. The stability of optical
signal transmission between the PT chip and the IR chip is ensured, the
light guide piece is a rigid transparent body with two fixed ends, and the surface of the light guide piece is coated with a layer of
titanium dioxide as a first reflecting layer, so that guide propagation of light can be realized, relative fixation of the PT chip and the IR chip can also be realized, and the stability of optical
signal transmission between the PT chip and the IR chip is ensured. The yield of the product in the production process is improved; the planar
optical coupler solves the problem that an existing planar
optical coupler is low in optical
signal transmission efficiency in the optical signal transmission process.