light modulator

Abstract

An optical modulator comprises a substrate 4 having a thickness of 20 μm or less and an electro-optic effect, a reinforcing substrate 6 holding the substrate 4 thereon and a resin layer 5 disposed between the substrate and the reinforcing substrate, in which the substrate 4 includes optical waveguides 1 and 2 and control electrodes 3 and 31 which control light waves propagating through the optical waveguide, in which the optical waveguides include at least two optical waveguides 1 separated from each other, and in which the control electrodes 31 disposed between the two optical waveguides are configured to include two electrodes 31 disposed along each optical waveguide, and a thin line 8 conducting the two electrodes 31 at a same potential.

Description

technical field [0001] The present invention relates to an optical modulator, in particular to an optical modulator comprising: a substrate having an electro-optical effect with a thickness of 20 μm or less; a reinforcing substrate holding the substrate; and a resin arranged between the substrate and the reinforcing substrate layer. Background technique [0002] In the technical fields of optical communication and optical measurement, electro-optical crystals such as lithium niobate (LN) are used for optical modulation, and optical waveguides with a Mach-Zehnder (MZ) structure formed on the crystal substrate are widely used. Traveling wave modulator. [0003] When reducing the thickness of the substrate constituting the optical modulator to about 20 μm, it is not necessary to form a substrate made of SiO between the substrate forming the optical waveguide and the control electrode. 2 The buffer layer is formed to match the speed of the light wave propagating in the optical...

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Problems solved by technology

When the applied DC bias voltage is increased to control the offset point of the modulation curve, the electric field will further penetrate into the resin layer 5, and as a result, the deterioration of the characteristics of the optical modulator will be further accelerated.

[0010] On the other hand, it is also possible to change the shape of the branched waveguide 1 and form the control electrode 30 by narrowing the space between the branched waveguides. However, in this case, a conversion part for changing the waveguide spacing is required, resulting in an increase in the length of the element.

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