Optical waveguide, optical module and optical system using the same

Claim 2

An optical waveguide comprising: a substrate (1); and at least one core waveguide (2) formed on said substrate for transmitting light therein; wherein said substrate is a pure SiO 2 synthetic silica glass substrate; a cladding layer covering the core and lining the substrate; said substrate having a deformation temperature at which its viscosity is 10 14 .5 poise, of more than 1000° C.

Claim 3

An optical waveguide according to claim 1, wherein: said pure SiO 2 synthetic silica glass substrate contains less than a predetermined concentration of hydroxyl groups.

Claim 4

An optical waveguide according to claim 2, wherein: the concentration of said hydroxyl groups is less than 300 ppm.

Claim 5

An optical waveguide according to claim 2, wherein: the concentration of said hydroxyl groups is less than 100 ppm.

Claim 6

An optical waveguide according to claim 2, wherein: the concentration of said hydroxyl groups is less than 50 ppm.

Claim 7

An optical waveguide according to claim 1, wherein: said pure SiO 2 synthetic silica glass substrate does not substantially contain chlorine.

Claim 8

An optical waveguide according to claim 1, wherein: said optical waveguide comprises an optical device including at least one of an optical star coupler, an optical multiplexer/demultiplexer, an optical switch, an optical modulator, a wavelength-independent optical coupler, and an optical transmission module.

Claim 9

An optical waveguide according to claim 1, wherein said substrate comprises a flat planar surface, and said at least one core waveguide is formed on a portion of said flat planar surface.

Claim 10

An optical waveguide according to claim 7, wherein said substrate comprises a flat planar surface, and said at least one core waveguide is formed on a portion of said flat planar surface.

Claim 11

An optical module comprising: a planar substrate; at least one core waveguide formed on said substrate for transmitting light therein; at least one optical device for emitting light into said at least one core waveguide or receiving light from said at least one core waveguide, said at least one optical device being connected to one end of said at least one core waveguide; a cladding layer covering the core and lining the substrate; and at least one optical fiber connected to an opposite end of said at least one core waveguide; wherein said substrate is a pure SiO 2 synthetic silica glass substrate having a deformation temperature at which its viscosity is 10 14 .5 poise, of more than 1000° C.

Claim 12

An optical module comprising: a planar substrate; at least one core waveguide formed on said substrate for transmitting light therein; at least one optical device for emitting light into said at least one core waveguide or receiving light from said at least one core waveguide, said at least one optical device being connected to one end of said at least one core waveguide; a cladding layer covering the core and lining the substrate; and at least one optical fiber connected to an opposite end of said at least one core waveguide; wherein said substrate is a pure SiO 2 synthetic silica glass substrate having a deformation temperature at which its viscosity is 10 14 .5 poise, of more than 1000° C.

Claim 13

An optical module according to claim 10, wherein said substrate comprises a flat planar surface, and said at least one core waveguide is formed on a portion of said flat planar surface.

Claim 14

An optical system comprising: an optical emitting module comprising: a planar substrate; at least one core waveguide formed on said substrate for transmitting light therein; at least one optical device for emitting light into said at least one core waveguide, said at least one optical device being connected to one end of said at least one core waveguide; a cladding layer covering the core and lining the substrate; wherein said substrate is a pure SiO 2 synthetic silica glass substrate having a deformation temperature at which its viscosity is 10 14 .5 poise, of more than 1000° C.; an optical receiving module comprising: a substrate; at least one core waveguide formed on said substrate for transmitting light therein; at least one optical device for emitting light into said at least one core waveguide, said at least one optical device being connected to one end of said at least one core waveguide; wherein said substrate is a pure SiO 2 synthetic silica glass substrate having a deformation temperature at which its viscosity is 10 14 .5 poise, of more than 1000° C.; an optical transmitter in which said optical emitting module is incorporated; an optical receiver in which said optical receiving module is incorporated; and an optical fiber for connecting said optical transmitter to said optical receiver.

Claim 15

An optical system comprising: an optical emitting module comprising: a planar substrate; at least one core waveguide formed on said substrate for transmitting light therein; at least one optical device for emitting light into said at least one core waveguide, said at least one optical device being connected to one end of said at least one core waveguide; a cladding layer covering the core and lining the substrate; wherein said substrate is a pure SiO 2 synthetic silica glass substrate having a deformation temperature at which its viscosity is 10 14 .5 poise, of more than 1000° C.; an optical receiving module comprising: a substrate; at least one core waveguide formed on said substrate for transmitting light therein; at least one optical device for emitting light into said at least one core waveguide, said at least one optical device being connected to one end of said at least one core waveguide; wherein said substrate is a pure SiO 2 synthetic silica glass substrate having a deformation temperature at which its viscosity is 10 14 .5 poise, of more than 1000° C.; an optical transmitter in which said optical emitting module is incorporated; an optical receiver in which said optical receiving module is incorporated; and an optical fiber for connecting said optical transmitter to said optical receiver.

Claim 16

An optical system according to claim 12, wherein each of said substrates comprises a flat planar surface, and said at least one core waveguide is formed on a portion of said flat planar surface.