PURPOSE: To simplify a laser oscillator in structure by a method wherein a stripe-like gold plating is provided to the surface of a laser rod, and the electrodes of the LDs provided to heat sinks are connected in series through the intermediary of the gold plating provided to the laser rod.

CONSTITUTION: Belt-like gold plating films 20 are provided to a laser rod 1, a gold plating film 20' is provided to each of four BeO heat sinks 8 confronting the laser rod 1, and the four BeO heat sinks 8 are bonded to the gold plating films 20 of the laser rod 1 with conductive adhesive agent 22. An LD 6 as an exciting light source is buried in each of the the heat sinks 8 so as to confront the laser rod 1, and the LDs 6 are electrically connected through the conductive films 20' provided to the heat sinks 8. Four blocks each composed of the heat sink 8 and the LD 6 are so arranged as to electrically connect laser diodes in series through the gold films 20' provided to the surface of the heat sinks 8 and the gold films 20 provided to the laser rod 1.