Abstract: A semiconductor laser device comprises a stem serving as a base; a laser diode LD submount having surface electrodes arranged thereon and joined to the surface of the stem; an LD chip joined to the surface electrode and connected with the surface electrode; and leads fixed in through holes formed in the stem by means of sealing parts and electrically connected to the surface electrodes via embedded layers in via holes formed in the LD submount, wherein grooves are formed in portions of the sealing parts or in portions of the LD submount around the connections between the leads and the embedded layers, to obtain a good modulated light waveform.

Abstract: A photomultiplier tube, a photomultiplier tube unit, and a performance-improved radiation detector for increasing a fixing area of a side tube in a faceplate while increasing an effective sensitive area of the faceplate. In the photomultiplier tube, a side face (3c) of the faceplate (3) protrudes outward from an outer side wall (2b) of a metal side tube (2), so that a light receiving area for receiving light passing through a light receiving face (3d) of the faceplate (3) is increased. The overhanging structure of the faceplate (3) is conceived based on a glass refractive index. The overhanging structure is aimed to receive light as much as possible which has not been received before. When the metal side tube (2) is fused to the glass faceplate (3), a fusing method is adopted due to joint between glass and metal. Joint operation between the faceplate (3) and the side tube (2) is reliably ensured. Accordingly, the overhanging structure of the faceplate (3) is effective.

Abstract: A photomultiplier tube, a photomultiplier tube unit, and a performance-improved radiation detector for increasing a fixing area of a side tube in a faceplate while increasing an effective sensitive area of the faceplate. In the photomultiplier tube, a side face (3c) of the faceplate (3) protrudes outward from an outer side wall (2b) of a metal side tube (2), so that a light receiving area for receiving light passing through a light receiving face (3d) of the faceplate (3) is increased. The overhanging structure of the faceplate (3) is conceived based on a glass refractive index. The overhanging structure is aimed to receive light as much as possible which has not been received before. When the metal side tube (2) is fused to the glass faceplate (3), a fusing method is adopted due to joint between glass and metal. Joint operation between the faceplate (3) and the side tube (2) is reliably ensured. Accordingly, the overhanging structure of the faceplate (3) is effective.