Laser light source device

Abstract

The fundamental wave light emitted from a semiconductor laser is converted in wavelength by a wavelength conversion element and emitted therefrom. A lighting circuit lights the semiconductor laser, and a temperature control unit 21b controls the amount of electric power supply to a heater so that the temperature of the wavelength conversion element turns into temperature at which the wavelength conversion efficiency thereof becomes optimal. When a state where the amount of electric power supply of the heater is lower limit or below continues for a predetermined period or longer, the hang-up suppressing unit 21c, or when duration time in a state where the temperature of the wavelength conversion element is higher than the control target temperature becomes higher than a constant value, laser lighting current is decreased by a preset amount, thereby recovery from a high temperature hang-up state performed.

Description

Laser light source device technical field The present invention relates to a wavelength conversion type laser light source device using a nonlinear optical crystal. More specifically, it relates to a laser light source device characterized by a method of controlling temperature so as to maximize the conversion efficiency of the nonlinear optical crystal in a wavelength conversion laser light source using a nonlinear optical crystal. Background technique Devices using laser light are being developed as light sources of projection projectors used in movies, home theaters, and the like. As such laser light sources, there are known cases where light radiated directly from a semiconductor laser element is used, and cases where light radiated from the semiconductor laser element is converted into another wavelength by a nonlinear optical crystal for use. Recently, as a blue or green laser light source, the use of periodically polarized lithium niobate (PPLN: Periodically Poled...

AI Technical Summary

Problems solved by technology

That is, in this state, even if the power supply to the heater is stopped, the temperature of the wavelength conversion element 5 cannot be lowered.

As described above, when the laser lighting current is increased according to the laser light quantity increase command, the heating amount of the wavelength conversion element 5 by the laser light also increases, and the temperature of the wavelength conversion element 5 may not be lowered to the optimum temperature, and cannot be controlled ( becomes a high temperature suspension state)

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