TRAVELING-WAVE TYPE OPTICAL MODULATOR AND OPTICAL MODULATION METHOD

• Main Authors: SUGAMATA TORU, HASHIMOTO YOSHIHIRO, KIUCHI KAZUMASA
• Format: Patent
• Language: English
• Published: 09.07.1999
• Edition: 6
• Subjects: DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF

PROBLEM TO BE SOLVED: To provide a traveling-wave type optical modulator and its optical modulation method capable of reducing the deterioration of an optical modulation characteristic even when optical modulation is executed at a high speed. SOLUTION: The modulator is provided with an optical wavegide 3 formed on a substrate 9 having at least an electro-optical effect and electrodes (earth electrodes 4 and a signal electrode 5) formed above or near to the waveguide 3 and capable of impressing an electric signal to light traveling in the waveguide 3 to modulate the light. Preferably the resistance value of a terminal resistor connected to the terminal part of the electrodes or the impedance of an electrode pad 11 is set up differently from the characteristic impedance of the electrodes, so that an electric signal reversed from the impressed electric signal is generated, the reverse electric signal and the original electric signal are synthesized and optical modulation is executed by using the synthetic electric signal.