Variable optical attenuator

• US 6,459,845 B1
• Filed: 03/08/2002
• Issued: 10/01/2002
• Est. Priority Date: 12/06/2001
• Status: Expired due to Fees

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Lee, Jung Hyun, Hong, Yoon Shik, Jung, Sung Cheon, Lee, Hyun Kee
• Primary Examiner(s): Lester, Evelyn A
• Application Number:
  US10/094,330
• Time in Patent Office: 207 Days
• Field of Search: 385/15, 385/16, 385/18, 385/19, 385/25, 385/31, 385/140
• US Class Current: 385/140
• CPC Class Codes: G02B 6/266 the optical element being an attenuator
• CPC Class Codes: G02B 6/353 the optical element being a shutter, baffle, beam dump or opaque element absorbers on light guide termination G02B6/243
• CPC Class Codes: G02B 6/3552 1x1 switch, e.g. on/off switch
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/358 Latching of the moving element, i.e. maintaining or holding the moving element in place once operation has been performed; includes a mechanically bistable system
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C

Abstract

A variable optical attenuator to provide a new drive mechanism for an actuator, whereby the amount of attenuation does not increase in geometric progression as voltage increases, and an exceptional resolution effect is achieved. The variable optical attenuator comprises a transmission fiber for transmitting beams of light, a reception fiber arranged on the same axis with the transmission fiber and receiving the light beams transmitted by the transmission fiber, a variable shutter arranged between the transmission and reception fibers, and moving vertically to cut off or transmit the light beams, thereby controlling an amount of attenuation, the variable shutter cutting off the light to have a maximum amount of attenuation at an initial position, a comb actuator for driving the variable shutter, and a spring for generating a spring force to return the variable shutter to its initial position, the spring force not being applied in the initial position having the maximum amount of attenuation when a drive voltage of the comb actuator is not applied, and spring force being applied when the variable shutter is driven.

Claims

1. A variable optical attenuator comprising:

a transmission fiber for transmitting beams of light;

a reception fiber arranged on the same axis with the transmission fiber and receiving the light beams transmitted by the transmission fiber;

a variable shutter arranged between the transmission and reception fibers, and moving vertically to cut off or transmit the light beams, thereby controlling an amount of attenuation, the variable shutter cutting off the light to have a maximum amount of attenuation at an initial position;

a comb actuator for driving the variable shutter; and

a spring for generating a spring force to return the variable shutter to its initial position, the spring force not being applied in the initial position having the maximum amount of attenuation when a drive voltage is not applied to the comb actuator, and spring force being applied when the variable shutter is moved.

2. The variable optical attenuator as set forth in claim 1, wherein the comb actuator has a differential circuit characterized as following equation, for linearly varying the amount of attenuation of the light as the drive voltage increases

  V_c=V_max−

V

where,

V_c;

control driving voltage,

V_max;

maximum voltage.

3. A variable optical attenuator comprising:

a transmission fiber for transmitting beams of light;

a reception fiber arranged at a predetermined angle to the transmission fiber and receiving the light beams transmitted by the transmission fiber;

a variable mirror arranged between the transmission and reception fibers, and moving vertically to reflect the light beams, thereby controlling an amount of attenuation, the variable mirror reflecting the light to have the maximum amount of attenuation at an initial position;

a comb actuator for driving the variable mirror; and

a spring for generating a spring force to return the variable mirror to its initial position, the spring force not being applied in the initial position having the maximum amount of attenuation when the drive voltage is not applied to the comb actuator, and being applied when the variable mirror is moved.

4. The variable optical attenuator as forth in claim 3, wherein the comb actuator has a differential circuit characterized as following equation, for linearly varying the amount of attenuation of the light as the drive voltage increases