PURPOSE: To allow provision of a containing space processing for an excess length of an optical fiber enough to be one direction only by providing a 1st port, a 2nd port and a 3rd port to the same side of the optical circuit module so as to attain same input output directions of the three optical fibers.

CONSTITUTION: Collimators 28, 30, 32 being ports are provided to an optical circuit module 10. These collimators 28, 30, and 32 are arranged side by side on one side of a case main body 34 at a proper interval, that is, on the same side of the case according to the design and the optical axes of them are made in parallel. The 2nd collimator 30 is provided to the left of the 1st collimator 28 and the 3rd collimator 32 is provided to the right of the 1st collimator 28. Since the input output direction of three optical fibers is the same, only one direction of an accommodating space to process an excess length of the optical fibers is enough. Thus, the accommodation performance of the optical fibers is improved. Thus, the size of the optical amplifier is miniaturized and the job efficiency is enhanced.