Noriaki ONODERA, Kenichiro TSUJI, Takuya WATANABE and Masatoshi SARUWATARI

Department of Communications Engineering, National Defense Academy 1-10-20 Hashirimizu, Yokosuka, Kanagawa, 239-8686 Japan

(Received November 26, 2004; Accepted January 18, 2005; Revised January 17, 2005)

Polarization-independent birefringent optical fiber loop filters with narrowband transmission characteristics are studied. Using Jones matrix analysis, a three-element fiber loop filter structure, performing as a Solc-type narrow band filter is designed and fabricated. By selecting proper splice angles between these three elements as well as their birefringence, a narrowband, polarization-independent periodic optical filter with 0.63-nm transmission bandwidth and 2.71-nm transmission period is realized.

Key words: optical filter, wavelength division multiplexing, fiber loop filter, birefringent filter, Solc filter, Sagnac loop mirror