Dispersion compensator with flattened transmission band

摘要

Light input from a single-mode fiber is collected into linear light beams by a line focuser, and collected on a VIPA element (10). A light beam output from the VIPA element (10) is made to pass through a space filter (13) having a predetermined transmission loss characteristic, and focused on a mirror (12) with a focusing lens (11). The light is reflected by the mirror (12), again passes through the space filter (13) via the focusing lens (11), enters the VIPA element (10), and again enters the single-mode fiber via the line focuser. The insertion loss wavelength characteristic of the wavelength dispersion compensator using the VIPA element (10) is optimized by being superimposed on the transmission loss characteristic of the space filter (13).