Light receiving module comprising stem and block on an upper surface of the stem

A light receiving module comprising:

• a stem having a circular shape;
• a plurality of lead pins penetrating through the stem and including a signal lead pin;
• a block provided on an upper surface of the stem;
• a waveguide light receiving device provided on a side surface of the block, the side surface of the block being substantially orthogonal to the upper surface of the stem;
• an amplifier provided on the side surface of the block and amplifying an electric signal output from the waveguide light receiving device;
• a first capacitor provided on the side surface of the block and connected to the waveguide light receiving device;
• a second capacitor provided on the side surface of the block and connected to the amplifier;
• a first relay substrate provided on the upper surface of the stem and arranged between the block and the signal lead pin;
• a first transmission line provided on the first relay substrate;
• a first wire connecting one end of the first transmission line and an output terminal of the amplifier;
• and
• a second wire connecting the other end of the first transmission line and the signal lead pin,
• wherein the plurality of lead pins includes a first power-source lead pin supplying electric power to the waveguide light receiving device and a second power-source lead pin supplying electric power to the amplifier,
• the first relay substrate is arranged between the first power-source lead pin and the second power-source lead pin,
• the first power-source lead pin is wire-connected to the first capacitor without the first relay substrate connected therebetween, and
• the second power-source lead pin is wire-connected to the second capacitor without the first relay substrate connected therebetween.