Bonded bodies for optical modulators, optical modulators and a method of producing bonded bodies for optical modulators
A bonded body for an optical modulator includes a supporting substrate, an optical waveguide material provided on the supporting substrate and composed of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate, and an optical waveguide in the optical waveguide material. The supporting substrate is composed of a material selected from the group consisting of magnesium oxide and a magnesium-silicon composite oxide.
1. A bonded body for an optical modulator, said bonded body comprising:
a supporting substrate;
an optical waveguide material provided on said supporting substrate and comprising a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate; and
an optical waveguide in said optical waveguide material,
wherein said supporting substrate comprises a material selected from the group consisting of steatite and forsterite, so as to provide an improved bandwidth of electro-optic modulation by the optical modulator.
2. The bonded body for the optical modulator of claim 1 , further comprising a bonding layer between said supporting substrate and said optical waveguide material.
3. The bonded body for the optical modulator of claim 2 , wherein said bonding layer comprises an oxide film.
4. An optical modulator comprising:
the bonded body for the optical modulator of claim 1 ; and
an electrode provided on said optical waveguide material and modulating a light propagating in said optical waveguide.
5. A method of producing a bonded body for an optical modulator, said method comprising the steps of:
bonding a supporting substrate comprising a material selected from the group consisting of steatite and forsterite, so as to provide an improved bandwidth of electro-optic modulation by the optical modulator, and an optical waveguide material comprising a material selected from the group consisting of lithium niobate, lithium tantalate and lithium niobate-lithium tantalate; and
providing an optical waveguide in said optical waveguide material.
6. The method of claim 5 , further comprising the step of providing a bonding layer between said supporting substrate and said optical waveguide material.
7. The method of claim 5 , further comprising the steps of:
forming a first oxide film on said optical waveguide material;
forming a second oxide film on said supporting substrate; and
directly bonding said first oxide film and said second oxide film.
8. The method of claim 7 , further comprising the steps of:
irradiating a neutralized atomic beam on a surface of said first oxide film to provide a first activated surface; and
irradiating a neutralized atomic beam on a surface of said second oxide film to provide a second activated surface,
wherein said first activated surface and said second activated surface are directly bonded with each other.