An optical bench with improved structure, in which tolerance for misalignment of optical elements becomes great with shortened optical path, is provided. The optical bench includes: a substrate (100); input and output optical fibers (120a, 120b, 150a, 150b) arranged on the substrate (100) with a predetermined separation gap therebetween, forming a zigzag pattern with far ends of …the input and output optical fibers (120a, 120b, 150a, isOb), for guiding input and output beams; input and output optical elements elements (130a, 130b, 160a, 160b) arranged at the far end of each input and output optical fiber (l2Oa, 120b, lSOa, l5Ob), for condensing and/or …diverging the input and output beams; and a plurality of micro-mirrors (140) for receiving the input beam from the input optical elements (130a, l3Ob) and reflecting the received input beam toward predetermined channels. The optical path in the optical bench is shortened so that …tolerance for misalignment of optical elements become great at reduced assembly costs. The optical bench has low insertion loss with maximum coupling efficiency.
Optical bench