Title:
VARIABLE WAVELENGTH FILTER
Document Type and Number:
Japanese Patent JP3201668
Kind Code:
B2
Abstract:
PURPOSE: To selectively and variably extract a light signal with optional wavelength from a light signal and vary the wavelength fast by using chiral smectic liquid crystal.
CONSTITUTION: This filter is constituted by sandwiching chiral smectic A liquid crystal 17 which is close to a temperature of transition to a smectic C phase by using an orientation film 16 for liquid crystal, a mirror 15, a transparent electrode 14, and a glass substrate 12; and only optional light is selected among light pulses having many wavelengths and the wavelength of the filter is varied fast. Liquid crystal molecules 11 can be oriented both in parallel and at perpendicular to the glass substrate 1, but the liquid crystal molecules are oriented at right angles here. For the parallel orientation, a reversed parallel rubbing processing is only performed similarly to the orientation of normal nematic liquid crystal and for the vertical orientation, a temperature gradient method is only employed. Consequently, the sweep speed of the wavelength of the liquid crystal variable wavelength filter can be made faster by three digits than before.
Inventors:
Katsuhiko Hirabayashi
Takashi Kurokawa
Takashi Kurokawa
Application Number:
JP2944993A
Publication Date:
August 27, 2001
Filing Date:
February 18, 1993
Export Citation:
Assignee:
Nippon Telegraph and Telephone Corporation
International Classes:
G01J3/26; G02B5/28; G02B6/00; G02F1/13; G02F1/137; (IPC1-7): G02F1/13; G02F1/137
Domestic Patent References:
| JP6465124A | ||||
| JP63706A |
Attorney, Agent or Firm:
Yasuyuki Tanaka (2 outside)