Laser oscillator

Abstract

A laser oscillator having a condensation prevention mechanism capable of extending the life span of a light emitting device while maintaining cost effectiveness as compared to the conventional technique is provided. The laser oscillator includes: a laser beam generating unit; a heat exchanger; a coolant bypass circuit; a coolant circuit connecting these components; a housing storing these components; a coolant circulating unit that circulates a coolant to the laser beam generating unit, the heat exchanger, and the coolant bypass circuit with the aid of the coolant circuit; a first valve that adjusts a flow rate of the coolant supplied to the laser beam generating unit; a second valve that adjusts a flow rate of the coolant supplied to the heat exchanger; a third valve that adjusts the flow rate of the coolant supplied to the coolant bypass circuit; a dew point measuring unit that measures a dew point inside the housing; a temperature measuring unit that measures a coolant temperature; and a control unit that controls the first, second, and third valves on the basis of the dew point and the coolant temperature.