Light emitting device and method for detecting abnormality in light emitting device

Abstract

A method for detecting abnormality in a light emitting device including a semiconductor laser element that is pulse-driven by pulse-control to emit excitation light, a wavelength conversion member including a phosphor and that emits fluorescent light by being irradiated with the excitation light, and a light receiving element disposed on a light extraction side of the wavelength conversion member and that detects the excitation light, the method includes: pulse-controlling an applied voltage with a pulse width shorter than a time from a start of voltage application until an optical intensity of light extracted from the wavelength conversion member reaches a maximum intensity, thereby pulse-driving the semiconductor laser element to achieve laser oscillation; measuring an optical intensity of the excitation light, or optical intensities of both the excitation light and the fluorescent light; and determining whether or not the optical intensity or the optical intensities falls within a prescribed range.

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