Yoshiro Matsuo

Double-stub structure for resonant-type optical modulators using 20-μm-thick electrode

We propose a resonant-type LiNbO/sub 3/ optical modulator with low halfwave voltage. We optimize the phase constant of the electric wave with thick electrodes to reduce the halfwave voltage. The halfwave voltage of the fabricated modulator with 20-/spl mu/m-thick electrodes is 5.8 V at 10.6 GHz.

Resonant-type optical modulator with double-stub structure

We investigated a resonant-type Mach-Zehnder optical modulator consisting of planar structures, designed to overcome the problems of making such a device and to increase the efficiency of the optical modulation. the electrode structure consists of modulating electrode and two stubs. The modulating electrode has two arms of the same length, and is an asymmetric coplanar waveguide.

Resonant electrode structures for band-operation-type optical modulators

Resonant structures for band-operation optical modulators were investigated in this paper. Modulation efficiency was enhanced by the resonance of the modulating electrode. We can optimize the resonant structures by using equivalent circuit model and numerical electro-magnetic analysis such as the finite element method. The electric field distribution on the electrode was directly measured by the EO sampling technique.

Reflection-type Mach-Zehnder LiNbO/sub 3/ optical modulator with double-stub structure

In order to obtain low-driving-voltage band-operation optical modulators, we investigated a reflection-type Mach-Zehnder LiNbO/sub 3/ optical modulator with double-stub structure. The double-stub structure consists of a modulating electrode and two stubs. The modulating electrode has two arms of the same length, and is an asymmetric coplanar waveguide (ACPW). A feeding line, which is a coplanar waveguide (CPW), is connected at the center of the modulating electrode. Two stubs, which are also CPWs of the same length, are also connected at the junction of the modulating electrode and the feeding line, so that we call it a double-stub structure.

Using electro-optic sampling in two-dimensional mapping of the distribution of electric field over a resonant electrode

In this study, we present some results of a rigorous experimental investigation of the distributions of electric field for two variants of the double-slab structure. Electro-optic (EO) sampling was used to measure the distribution of electric field over the electrode.