Semiconductor laser light source device

A semiconductor laser light source device comprising:

• a metal stem;
• first to third lead pins penetrating through the metal stem;
• a support block provided on the metal stem;
• a temperature control module mounted on a side surface of the support block and including a lower substrate, an upper substrate, and a plurality of thermoelectric devices put between the lower substrate and the upper substrate;
• a dielectric substrate having a back surface joined to the upper substrate of the temperature control module;
• two differential driving signal lines provided on a principal surface of the dielectric substrate;
• a semiconductor light modulation device mounted on the principal surface of the dielectric substrate;
• a temperature sensor mounted on the principal surface of the dielectric substrate;
• a first conductive wire connecting one end of one of the differential driving signal lines and the semiconductor light modulation device;
• a second conductive wire connecting the other end of the differential driving signal line and the first lead pin;
• a third conductive wire connecting the temperature sensor and the second lead pin;
• and
• a fourth conductive wire connecting the temperature control module and the third lead pin,
• wherein the first and second lead pins are arranged on the principal surface side of the dielectric substrate, and
• the third lead pin is arranged on a back surface side of the dielectric substrate,
• the lower substrate has a protruding portion protruding above the upper substrate,
• a metalized portion for supplying power to the thermoelectric devices is provided at the protruding portion,
• a temperature control module conductor is provided from the principal surface to an upper side surface of the dielectric substrate, and
• the fourth conductive wire includes a conductive wire connecting the temperature control module conductor provided on the upper side surface of the dielectric substrate and the third lead pin, and a conductive wire connecting the temperature control module conductor provided on the principal surface of the dielectric substrate and the metalized portion.