Title:
OPTICAL PHASE MODULATION SYSTEM
Document Type and Number:
Japanese Patent JP3200138
Kind Code:
B2
Abstract:
PURPOSE: To suppress an intensity modulation component generated in the case of phase-modulating by the field absorption type optical modulator of a single body by optically coupling two field absorption type optical modulators and subjecting to modulation with signals having opposite polarity and then to push-pull-driving.
CONSTITUTION: The field absorption type optical modulators 1a, 1b are coupled optically. A signal outputted from a signal source 2 is branched and the polarity of one side is inverted by an inverter 9. After the branched electric signals are amplified to required amplitudes by amplifiers 6a, 6b respectively, a phase difference between both signals is adjusted by a variable delay line 8, and are inputted to the field absorption type optical modulators 1a, 1b respectively. DC bias voltage is supplied to the field absorption type optical modulators 1a, 1b by DC power sources 3a, 3b respectively. Then only the intensity modulation component is canceled and a phase modulation component is remained by changing the driving conditions (bias voltage and driving amplitude) of the field absorption type optical modulators 1a, 1b and the length of an element.
Inventors:
Kichi Makoto Ta
Masaru Iwashita
Masaru Iwashita
Application Number:
JP5076492A
Publication Date:
August 20, 2001
Filing Date:
March 09, 1992
Export Citation:
Assignee:
Nippon Telegraph and Telephone Corporation
International Classes:
G02F1/025; G02F1/015; (IPC1-7): G02F1/025; G02F1/015
Domestic Patent References:
| JP5283804A | ||||
| JP61143721A |
Attorney, Agent or Firm:
Akihide Sugimura (1 outside)