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.

A wavelength conversion member that includes a single crystal phosphor and has a high yield rate is provided. A light emitting unit (1) is a wavelength conversion member that converts a wavelength of a laser light output from a laser light source and includes a phosphor layer (1a) formed of a single crystal phosphor. A plane orientation of a principal plane (1b), which has an area larger than those of divided planes, of the phosphor layer is {111}, and a plane orientation of some divided planes out of the plurality of divided planes is {1-10}.

A light emission device includes a light source that emits an excitation light beam, a light deflector, a wavelength converter that receives and converts the excitation light beam deflected by the light deflector to wavelength-converted light, and a light concentration section that focuses the excitation light beam on the wavelength converter. The light concentration section includes a first optical system disposed between the light source and the light deflector, and a second optical system disposed between the light deflector and the wavelength converter. In the second optical system, a focal length of an Ay-axis is shorter than a focal length of an Ax-axis, where the Ax-axis is defined as an axis that has a lowest beam parameter product of the excitation light beam, and the Ay-axis is defined as an axis orthogonal to the Ax-axis in a cross section perpendicular to a propagation direction of the excitation light beam.

A lamp unit includes: a laser light source having a CAN type package; a pedestal having a back surface in contact with a heat sink and a front surface on which the laser light source is mounted; and a pressing member that abuts onto an abutting portion of the laser light source and presses the laser light source in a direction toward the pedestal. The pressing member and the pedestal are fixed to the heat sink by fastening with a common fixing member.

A wavelength conversion element includes a wavelength conversion layer having a first surface on which excitation light is incident, a second surface located on the side opposite the first surface, a plurality of phosphor particles that convert the excitation light in terms of wavelength to produce fluorescence, and a binder that holds the plurality of phosphor particles. The plurality of phosphor particles have a particle diameter distribution, and the minimum particle diameter in the particle diameter distribution of a plurality of the phosphor particles contained in a first region located on the side facing the first surface is greater than the minimum particle diameter in the particle diameter distribution of a plurality of the phosphor particles contained in a second region located on the side facing the second surface.

A wavelength conversion element includes a wavelength conversion layer having a first surface which excitation light enters, and a second surface opposed to the first surface, and adapted to perform wavelength conversion on the excitation light, a substrate disposed so as to be opposed to the second surface, and a bonding layer adapted to bond the wavelength conversion layer and the substrate to each other, and the bonding layer has a first bonding material disposed in a first region opposed to an incident area of the excitation light in the second surface, and a second bonding material disposed in at least a second region located on an outer periphery of the first region and lower in Young's modulus than the first bonding material.

A wavelength conversion member that includes a single crystal phosphor and has a high yield rate is provided. A light emitting unit (1) is a wavelength conversion member that converts a wavelength of a laser light output from a laser light source and includes a phosphor layer (1a) formed of a single crystal phosphor. A plane orientation of a principal plane (1b), which has an area larger than those of divided planes, of the phosphor layer is {111}, and a plane orientation of some divided planes out of the plurality of divided planes is {1-10}.

A semiconductor light source is disclosed. In one embodiment, a semiconductor light source includes at least one semiconductor laser for generating a primary radiation and at least one conversion element for generating a longer-wave visible secondary radiation from the primary radiation, wherein the conversion element for generating the secondary radiation comprises a semiconductor layer sequence having one or more quantum well layers, and wherein, in operation, the primary radiation is irradiated into the semiconductor layer sequence perpendicular to a growth direction thereof, with a tolerance of at most 15.

A semiconductor light emitting device includes a substrate a semiconductor light emitting element that is disposed on the substrate and that emits light along a direction substantially parallel to a main surface of the substrate a wavelength conversion element that is disposed on a light emitting side of the semiconductor light emitting element, that absorbs a portion of the light emitted from the semiconductor light emitting element, and that emits light having a wavelength different from that of the absorbed light; and a holding member that is disposed on the substrate and holds the wavelength conversion element.

A light source device includes: a semiconductor light emitting device which emits laser light; a wavelength conversion component which emits fluorescence by being irradiated with the laser light emitted from the semiconductor light emitting device as excitation light; and a photodetector on which a portion of light emitted from the wavelength conversion component is incident. The photodetector is disposed at a location off a light path of usable radiation light which is emitted from the wavelength conversion component to a space and used as illumination light.