Optical receiving sub-module and passive alignment method thereof

The invention discloses an optical receiving sub-module composed of a planar optical waveguide chip and a photodiode chip and a passive alignment method thereof. The optical receiving sub-module comprises a bearing plate, a planar optical waveguide chip arranged on the bearing plate, a supporting plate and a plurality of photodiode chips. The planar optical waveguide chip comprises a substrate and a planar optical waveguide. The planar optical waveguide comprises an input optical waveguide core adjacent to an input end, a plurality of output optical waveguide cores adjacent to an output end, an optical coupling part respectively connected with the input optical waveguide core and the plurality of output optical waveguide cores, and a reflecting mirror formed on the side surface of the output end of the planar optical waveguide chip. An acute included angle is formed between the output end side face and an upper surface of the planar optical waveguide chip, and the output end side face and the planar optical w