Optical wavelength tuning method and Fabry-Perot type optical tuner

• US 6,639,648 B2
• Filed: 05/21/2001
• Issued: 10/28/2003
• Est. Priority Date: 05/25/2000
• Status: Expired due to Fees

• Current Assignee: Shoei Kataoka
• Original Assignee: Shoei Kataoka
• Inventors: Kataoka, Shoei
• Primary Examiner(s): Ton, Toan
• Application Number:
  US09/861,835
• Publication Number:
  US 20020005918A1
• Time in Patent Office: 890 Days
• Field of Search: 349/198, 359/589, 359/618, 359/260, 385/39, 385/8, 385/28
• US Class Current: 349/198
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 6/351 involving stationary waveguides with moving interposed optical elements G02B6/3538 takes precedence; interposed waveguides G02B6/3502
• CPC Class Codes: G02B 6/3552 1x1 switch, e.g. on/off switch
• CPC Class Codes: G02B 6/3568 characterised by the actuating force
• CPC Class Codes: G02B 6/3578 Piezoelectric force piezoelectric forces controlling reflecting elements in general G02B26/0858; piezo-optic devices G02F1/0131
• CPC Class Codes: G02F 1/216 using liquid crystals, e.g. liquid crystal Fabry-Perot filters

Abstract

There is provided a small and lightweight Fabry-Perot type optical tuner. By changing the distance between the reflector plates 3A and 3B with an applied voltage across said reflector plates 3A and 3B, wherein said reflector plates 3A, 3B are supported with coil springs 8A, 8B, and at the same time by changing the refractive index of the liquid crystal material 9, i.e. by utilizing both changes of distance d and refractive index n, an optical tuning can be obtained over a wide range of optical wavelength.

Claims

1. A Fabry-Perot type optical tuner, comprising:

Fabry-Perot type optical cavity wherein a tuned wavelength changes according to the distance between opposing reflector plates;

a distance changing unit for changing said distance;

liquid crystal material filled in between said opposing reflector plates having a refractive index changeable by an applied electric field to said liquid crystal material; and

an electric field applying unit for changing the strength of the electric field applied to said liquid crystal material.

2. A Fabry-Perot type optical tuner according to claim 1, wherein said distance changing unit comprises male screws to fit in female screws provided at plural parts of one of two opposing transparent substrate plates supporting said reflector plates, and the distance between said transparent substrate plates is changed by rotating said male screws.

3. A Fabry-Perot type optical tuner according to claim 1, wherein said distance changing unit comprises piezo-electric elements connecting two opposing transparent substrate plates supporting said reflector plates, and the distance between said transparent substrate plates is changed by applying an electric voltage to said piezo-electric elements to elongate or to shrink said piezo-electric elements.

4. A Fabry-Perot type optical tuner according to claim 1, wherein said distance changing unit comprises:

elastic elements to support elastically two opposing transparent substrate plates supporting said reflector plates; and

opposing electrostatic attracting plates provided on said two transparent substrate plates for changing the distance between said transparent substrate plates against the elastic force of said elastic elements by applying an electric voltage to said electrostatic attracting plates.

5. A Fabry-Perot type optical tuner according to claim 4, wherein said electrostatic attracting plates are concurrently said electric field applying unit to the liquid crystal material.

6. A Fabry-Perot type optical tuner according to claim 4, wherein said elastic elements to support elastically the transparent substrate plates are flexible spacers.