Title:
VARIABLE WAVELENGTH FILTER
Document Type and Number:
Japanese Patent JPH0545618
Kind Code:
A
Abstract:
PURPOSE:To attain the transmittance and half-value width which are applicable to frequency multiplex communication in a 1.3 to 1.55mum band. CONSTITUTION:This variable wavelength filter is constituted by laminating and disposing a glass substrate 8A, a transparent electrode layer 5A, a high reflection mirror 4A, an oriented film 3A, a liquid crystal layer 1, an oriented film 3B, a glass plate 2 or high-polymer film 18 having the refractive index coincident with the refractive index of the liquid crystal of the liquid crystal layer 1, a high reflection mirror 4B, a transparent electrode layer 5B, and a glass substrate 8B in this order. The increase in the absorption scattering of an etalon cavity is obviated in spite of increasing of the cavity length by disposing the two layers consisting of the liquid crystal layer 1 and the glass plate 2 or high-polymer film having the refractive index coincident with the refractive index of the liquid crystal thereof into this cavity. The half-value width can, therefore, be narrowed and the transmittance increased and 0.07nm half value width, >=35% transmittance and 12nm variable width, which are the requirements for FDMs are attained.
Inventors:
HIRABAYASHI KATSUHIKO
TSUDA HIROYUKI
KUROKAWA TAKASHI
TSUDA HIROYUKI
KUROKAWA TAKASHI
Application Number:
JP1381192A
Publication Date:
February 26, 1993
Filing Date:
January 29, 1992
Export Citation:
Assignee:
NIPPON TELEGRAPH & TELEPHONE
International Classes:
G02F1/13; G02F1/1335; H04B10/00; (IPC1-7): G02F1/13
Attorney, Agent or Firm:
Yoshikazu Tani (1 person outside)
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