Integrated-optic variable delay line and its application to a low-coherence reflectometer.
We propose a large-scale variable delay line based on planar light-wave circuit technology and its application as a reference arm in an optical low-coherence reflectometer. This variable delay line is composed of 16 asymmetrical delay arm pairs sandwiched between 2 optical switches, which select the path for a needed delay. This configuration enables us to eliminate the need for a moving part in the reflectometer. We can scan the reference arm over a length of 262.1 mm with a step of less than 1.0 microm in air and achieve reflectometer sensitivity of about -47 dB.
Takiguchi
K
K
NTT Photonics Laboratories, NTT Corporation, Atsugi, Kanagawa, Japan. taki@aecl.ntt.co.jp
Itoh
M
M
Takahashi
H
H