Optical module

An optical module comprising:

• a conductive block with a first surface and a second surface, the conductive block having some through holes extending therethrough between the first surface and the second surface;
• some lead pins including a signal lead pin, the lead pins fixed inside the respective through holes and insulated from the conductive block;
• a thermoelectric cooler with an upper surface and a lower surface, the lower surface fixed to the first surface of the conductive block, the thermoelectric cooler having a Peltier device therein configured to transfer heat between the upper surface and the lower surface;
• a metal layer laminated on the upper surface of the thermoelectric cooler;
• a ground wire connecting the first surface of the conductive block and the metal layer;
• a photoelectric device adapted to convert an optical signal and an electrical signal at least from one to another;
• a mounting substrate on which the photoelectric device is mounted, the mounting substrate fixed to the upper surface of the thermoelectric cooler with at least the metal layer interposed therebetween, the mounting substrate having a first wiring pattern electrically connected to the photoelectric device;
• a relay substrate having a second wiring pattern electrically connected to the signal lead pin;
• and
• a signal wire configured to connect the first wiring pattern and the second wiring pattern.