Laser module

A laser module comprising:

• 2M−1 laser diodes emitting laser beams, where M is a natural number of not less than 2;
• and
• an optical fiber,
• the laser beams being caused to enter the optical fiber,
• the 2M−1 laser diodes being spatially clustered such that among light beams constituting return light emitted from the optical fiber, a light beam on an optical axis does not meet active layers of the 2M−1 laser diodes at respective exit end surfaces of the 2M−1 laser diodes, the light beam on the optical axis being emitted at an emission angle of 0°,
• the 2M−1 laser diodes being arranged such that the respective exit end surfaces of the 2M−1 laser diodes are provided at 2M−1 points x1, x2, . . . , xM, and xN−M+2, xN−M+3, . . . , xN selected from among N points x1, x2, . . . , xN, where N is a natural number of not less than 2M+1, the N points x1, x2, . . . , xN being provided at equal intervals on a certain line segment or a certain circular arc and arranged such that a relation of optical path lengths Lj from respective points xj to an entrance end surface of the optical fiber is L1>L2>. . . >LN.