Abstract: A thread forming tap (1) is provided with a male thread portion (3), a groove, and an inside diameter finishing blade (61). A chamfer portion (31) of the male thread portion (3) is provided continuous with the complete thread portion (32) and decreases in diameter toward a tip end. The groove is provided parallel to a shaft center spanning the complete thread portion (32) and the chamfer portion (31) so as to divide a thread (71) of the male thread portion (3). On the chamfer portion (31) and the complete thread portion (32), the inside diameter finishing blade (61) is provided along an open edge of the groove on the side opposite the rotational direction of the thread forming tap (1). The inside diameter finishing blade (61) cuts and removes a crest portion of the female thread formed on a surface layer of a pilot hole (90).

Abstract: A semiconductor laser module of the present invention comprises a semiconductor laser, a pig tail optical fiber, a optical part, and a transition metal doped optical fiber. The optical part optically couples the semiconductor laser and the pig tail optical fiber to each other. The transition metal doped optical fiber is formed in a length corresponding to an attenuation amount with which desired distortion characteristics and desired noise characteristics are realized, and is connected to the side of the pig tail optical fiber opposite to the side which faces the semiconductor laser. The distortion characteristics of the semiconductor laser is improved by the action of the transition metal doped optical fiber. Consequently, the yield of semiconductor laser modules is improved.