OPTICAL MODULE

PROBLEM TO BE SOLVED: To suppress the deviation of the optical axis of a collimator due to variation in the volume of solder material, which occurs in the solidification process of solder. SOLUTION: An optical module is formed by inserting the tip parts of collimators 2a and 2b into both end parts of a cylindrical casing 3, respectively, fixing the tip parts of the collimators 2a and 2b on the inner wall face of the casing 3 with solder. In the fixing process with soldering, the optical axes of the collimators 2a and 2b are kept coincident with each other by clamping and fixing the collimators 2a and 2b with a clamping member 12, a solder material 13 is supplied from a solder feeding port 8 of the casing 3 and melted by being heated in a state that the casing 3 is not clamped but kept free, and then the solder material 13 existing between each of the tip parts of the collimators 2a and 2b and the inner wall face of the casing 3 is cooled and solidified. The casing 3 is moved by the variation in the volume due to a rapid contraction of the solder material 13 during the solidifying process, thus the contraction force is released. The deviation of the optical axes of the collimators 2a and 2b due to the contraction force is suppressed.