| 摘要 |
<p>A small, power-saving flat optical waveguide circuit type optical variable attenuator capable of attaining an arbitrary light attenuation amount in a range of 0-10 dB and a light attenuation amount of at least 30 dB. The attenuator has, in the middle, in the longitudinal direction of optical waveguides (1a, 1b, 1d), of at least one of the input optical waveguides (1a, 1b) and output optical waveguide (1d) of a Mach-Zehnder interferometer circuit (30), a slit (12) formed in the optical waveguide layer (3) in a direction crossing the optical waveguides (1a, 1b, 1d), and matching material moving means (16a, 16b) for moving an index-matching material (13) set in part of the slit (12) between a position including the passage of the propagation light of the optical waveguides (1a, 1b, 1d) and a position retracted from the passage of the propagation light.</p> |
