发明名称 |
Optical wavelength monitoring apparatus |
摘要 |
In an optical wavelength monitoring apparatus for easily monitoring wavelength deviation, light introduced from a laser source 10 to an optical transmission line 12 is divided by directional couplers 14, 20. Optical output of the directional coupler 14 is converted into an electrical signal by a photodiode 16, and logarithmic-amplified by a logarithmic amplifier 18. Optical output of the directional coupler 20 is introduced to a photodiode 26 via an optical filter 24. The optical filter 24 is an optical element whose transmittance decreases as the incident light deviates from a specific wavelength lambda a. Optical output from the optical filter 24 is converted into an electrical signal by a photodiode 26, and logarithmic-amplified by a logarithmic amplifier 28. A differential amplifier 30 outputs a difference between outputs of the amplifiers 18, 28. A comparator 32 compares the output of the differential amplifier 30 with an alarm threshold Vref, and outputs an alarm-on signal when the difference is Vref or higher.
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申请公布号 |
US5898502(A) |
申请公布日期 |
1999.04.27 |
申请号 |
US19970878543 |
申请日期 |
1997.06.19 |
申请人 |
KOKUSAI DENSHIN DENWA KABUSHIKI KAISHA;KDD SUBMARINE CABLE SYSTEMS INC. |
发明人 |
HORIUCHI, YUKIO;YAMAMOTO, SHU |
分类号 |
G01J1/16;G01J9/00;H04B10/08;(IPC1-7):H04B110/08;G01J3/51 |
主分类号 |
G01J1/16 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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