Optical modulator
AssigneeFujitsu Limited
InventorMasaki Sugiyama
Life of this patent
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Abstract
In an optical modulator, lights that have been branched by an input optical branching section are input via curved waveguides to a plurality of optical modulation sections arranged in parallel on the same substrate. In the optical modulation sections, optical branching sections of an MZ type optical waveguide are arranged shifted to an output side in the longitudinal direction (x direction) of the substrate, corresponding to an arrangement of input ends of signal electrodes. As a result, even if the input ends of the signal electrodes of the respective optical modulation sections are arranged side by side with a predetermined spacing on one side face of the substrate, input light can be applied to the respective optical modulation sections at low loss, without incurring an increase in the drive voltage.
Claims17
An optical modulator comprising a plurality of optical modulation sections which are arranged in parallel on a same substrate having an electro-optic effect, in the respective optical modulation sections, a Mach-Zehnder type optical waveguide is formed on the substrate, and a signal electrode and an earth electrode are provided along a pair of branching waveguides that are disposed between an optical branching section and an optical multiplexing section of the Mach-Zehnder type optical waveguide, that perform modulation of light that propagates on the Mach-Zehnder type optical waveguide by applying an electric signal corresponding to modulation data to the signal electrode that is a travelling wave electrode, wherein:
- the optical modulator comprises;
- an input optical branching section that branches light input from a single input port arranged on an input end face of the substrate into a plurality of lights, and
- a plurality of curved waveguides that guide the lights branched by the input optical branching section to an input end of the Mach-Zehnder type optical waveguide of the respective optical modulation sections,
- and in the signal electrodes of the respective optical modulation sections, each of the input ends to which the electric signal is applied are arranged side by side with a predetermined spacing on one side face of opposite side faces that intersect with the input end face of the substrate,
- and the optical branching sections of the respective optical modulation sections are arranged shifted to the output side in a first direction parallel with the opposite side faces of the substrate, corresponding to the arrangement of the input ends of the signal electrodes.
Dependencies are inferred from the claim text.