Light modulator and its fabrication method

Abstract

It is possible to provide a light modulator using a thin plate having a thickness of 20 mum or below capable of stably holding a conductive film suppressing troubles such as resonance phenomenon of microwaves in a substrate and pyro-electric phenomenon. It is also possible to provide a method for fabricating the light modulator. The light modulator includes: a thin plate (10) formed of a material having a photoelectric effect and having a thickness of 20 mum or below; light waveguide (11) formed on the front or rear surface of the thin plate; and modulation electrodes (13, 14) formed on the front surface of the thin plate for modulating light passing through the light waveguide. The light modulator further includes a reinforcing plate (16) bonded to the rear surface of the thin plate and a conductor film (17) formed on the side surface of the thin plate continuously to the side surface of the reinforcing plate.

Description

technical field [0001] The present invention relates to a light modulator, and more particularly to a light modulator comprising a thin plate and a reinforcing plate, wherein the thin plate is formed of a material having an electro-optical effect and has a thickness of 20 μm or less, and the reinforcing plate is bonded to the back of the thin plate and has a thickness of thicker than the sheet. Background technique [0002] Conventionally, in the field of optical communication or optical measurement, waveguide-type optical modulators in which optical waveguides or modulation electrodes are formed on a substrate having an electro-optical effect have been frequently used. [0003] In an optical modulator using a substrate having an electro-optical effect, as in Patent Document 1 or 2, etc., by forming a conductive film as shown in FIG. The occurrence of the resonance phenomenon that the microwave applied by the device resonates in the substrate, or the pyroelectric effect gen...

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Problems solved by technology

[0011] However, when the above-mentioned conductive film is formed on the side surface of a thinned substrate (hereinafter referred to as "thin plate"), since the thickness of the substrate is thin and the surface of the side surface of the thin plate is extremely small, the bonding force between the substrate and the conductive film is weak. The disadvantage that the conductive film and the substrate are easily peeled off occurs

[0012] In addition, due to the thinning of the substrate, the confinement of the light wave propagating on the optical waveguide is weakened, resulting in the phenomenon that the light distribution of the light wave expands in the lateral direction (the direction perpendicular to the thickness direction of the thin plate) or the thickness direction of the thin plate. If, when in When a conductive film is formed on the back surface of the substrate, problems such as light waves being scattered or absorbed by the conductive film may occur

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