A new method to measure the facet reflectivity of an antireflection (AR)-coated electroabsorption (EA) modulator in the region of operating wavelengths is proposed. First, by measuring induced photocurrent and reflectance simultaneously at the front facet of an EA waveguide, the cleaved facet reflectivity and propagation loss are determined. After coating the facet with AR, the residual reflectivity of AR-coated facet is obtained from the measured photocurrent spectra and the predetermined facet reflectivity. We demonstrate the reflectivity of a double- layer AR-coated EA modulator can be measured to be ∼4 × 10-4 at 1.55 μm for TE polarization by using the proposed technique.
Bibliographical noteFunding Information:
Manuscript received April 24, 2000; revised August 10, 2000. This work was supported by the Brain Korea 21 Project and the Advanced Photonics Technology Project. B.-K. Kang and S.-H. Park are with the Department of Physics, Yonsei University, Seoul 120-749, Korea (e-mail: email@example.com). Y. H. Park, S. Lee and S. S. Choi are with the Photonics Research Center, Korea Institute of Science and Technology, Cheongryang, Seoul 130-650, Korea. J. Lee and T. Kamiya are with the Department of Electronic Engineering, The University of Tokyo, Bunkyo-Ku, Tokyo 113-8656, Japan. Publisher Item Identifier S 1041-1135(01)01059-X.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering