Abstract: A light emitting unit includes a light emitting sealed body and a voltage application circuit. The light emitting sealed body includes a container to which laser light for maintaining plasma is incident and from which light from the plasma is emitted, a first electrode which includes a first discharge portion, and a second electrode which includes a second discharge portion. An end portion of the first discharge portion has a shape in which a thickness is thinned as it goes toward the second discharge portion and an end surface of the second discharge portion extends along a plane perpendicular to an extending direction of the first discharge portion. The voltage application circuit controls a potential difference between the first electrode and the second electrode by adjusting a voltage applied to at least the first electrode.

Abstract: In a light source device, a control unit causes an energy density of a laser light in a lighting start region RS when a laser support light is maintained to be lower than an energy density of the laser light in the lighting start region RS when the laser support light is put on. For this reason, when the laser support light is maintained, a laser light L is radiated to the lighting start region RS at an energy density of a degree where sputtering does not occur. Therefore, in the light source device, because sputtering in a light emission sealing body can be suppressed, a sufficiently long life can be realized.

Abstract: In a light-emitting sealed body, a metal structure (electron emission structure) containing an easily electron-emitting material is used, so that it is not necessary to perform feeding for discharge between electrodes. Therefore, a feeding member does not need to be connected to the metal structure from the outside of a bulb. In addition, in the light-emitting sealed body, the metal structure is disposed in an internal space S of the bulb and a positioning unit of the metal structure is disposed only in the bulb. Therefore, in the light-emitting sealed body, the metal structure and the positioning unit do not penetrate the bulb and are not buried in the bulb and weakened portions are not formed in the bulb made of glass. Therefore, a sealing state of the bulb can be maintained surely.

Abstract: In a light source device, a control unit causes an energy density of a laser light in a lighting start region RS when a laser support light is maintained to be lower than an energy density of the laser light in the lighting start region RS when the laser support light is put on. For this reason, when the laser support light is maintained, a laser light L is radiated to the lighting start region RS at an energy density of a degree where sputtering does not occur. Therefore, in the light source device, because sputtering in a light emission sealing body can be suppressed, a sufficiently long life can be realized.

Abstract: In a light source device, a control unit causes an energy density of a laser light in a lighting start region RS when a laser support light is maintained to be lower than an energy density of the laser light in the lighting start region RS when the laser support light is put on. For this reason, when the laser support light is maintained, a laser light L is radiated to the lighting start region RS at an energy density of a degree where sputtering does not occur. Therefore, in the light source device, because sputtering in a light emission sealing body can be suppressed, a sufficiently long life can be realized.

Abstract: In a light source device, a control unit causes an energy density of a laser light in a lighting start region RS when a laser support light is maintained to be lower than an energy density of the laser light in the lighting start region RS when the laser support light is put on. For this reason, when the laser support light is maintained, a laser light L is radiated to the lighting start region RS at an energy density of a degree where sputtering does not occur. Therefore, in the light source device, because sputtering in a light emission sealing body can be suppressed, a sufficiently long life can be realized.

Abstract: In a light source device, a control unit causes an energy density of a laser light in a lighting start region RS when a laser support light is maintained to be lower than an energy density of the laser light in the lighting start region RS when the laser support light is put on. For this reason, when the laser support light is maintained, a laser light L is radiated to the lighting start region RS at an energy density of a degree where sputtering does not occur. Therefore, in the light source device, because sputtering in a light emission sealing body can be suppressed, a sufficiently long life can be realized.

Abstract: In a light-emitting sealed body, a metal structure (electron emission structure) containing an easily electron-emitting material is used, so that it is not necessary to perform feeding for discharge between electrodes. Therefore, a feeding member does not need to be connected to the metal structure from the outside of a bulb. In addition, in the light-emitting sealed body, the metal structure is disposed in an internal space S of the bulb and a positioning unit of the metal structure is disposed only in the bulb. Therefore, in the light-emitting sealed body, the metal structure and the positioning unit do not penetrate the bulb and are not buried in the bulb and weakened portions are not formed in the bulb made of glass. Therefore, a sealing state of the bulb can be maintained surely.

Abstract: In a light source device, a control unit causes an energy density of a laser light in a lighting start region RS when a laser support light is maintained to be lower than an energy density of the laser light in the lighting start region RS when the laser support light is put on. For this reason, when the laser support light is maintained, a laser light L is radiated to the lighting start region RS at an energy density of a degree where sputtering does not occur. Therefore, in the light source device, because sputtering in a light emission sealing body can be suppressed, a sufficiently long life can be realized.