Electrode and core arrangements for polarization-independent waveguides

An electrooptic waveguide for an optical signal, said optical signal including both a horizontally oriented component TE and a vertically oriented component TM, said waveguide comprising a plurality of control electrodes, an optical waveguide core, and a cladding optically coupled to said optical waveguide core, wherein;

• at least one of said core and said cladding comprises an electrooptic material poled along a poling contour;
• one of said control electrodes defines an electrode thickness dimension substantially less than a corresponding electrode thickness of a thicker remaining control electrode;
• said control electrodes are positioned to generate a contoured electric field across said poled electrooptic material;
• said poled electrooptic material defines an array of local TM indices of refraction nTM corresponding to the indices of refraction for said vertically oriented component TM of said optical signal in said poled electrooptic material;
• said poled electrooptic material defines an array of local TE indices of refraction nTE corresponding to the indices of refraction for said horizontally oriented component TE of said optical signal in said poled electrooptic material;
• said local TM indices nTM and said local TE indices nTE are each a function of a first electrooptic coefficient rPP for light parallel to a local component of said contoured electric field and a second electrooptic coefficient rIP for light perpendicular to a local component of said contoured electric field;
• a difference between said first and second electrooptic coefficients rPP and rIP defines an optical birefringence of said poled electrooptic material;
• said local TM indices nTM collectively define a TM mode index of said waveguide;
• said local TE indices nTM collectively define a TE mode index of said waveguide;
• and
• said respective orientations of said contoured electric field and said poling contour are configured to compensate for said optical birefringence of said poled electrooptic material such that said TM mode index of said waveguide is substantially equal to said TE mode index of said waveguide.

An electrooptic waveguide for an optical signal, said optical signal including both a horizontally oriented component TE and a vertically oriented component TM, said waveguide comprising a plurality of control electrodes, an optical waveguide core, and a cladding optically coupled to said optical waveguide core, wherein:

• at least one of said core and said cladding comprises an electrooptic material poled along a poling contour;
• said control electrodes define a symmetric configuration relative to an axis of symmetry and are positioned to generate a contoured electric field across said poled electrooptic material
• said optical waveguide core is offset from said axis of symmetry;
• said poled electrooptic material defines an array of local TM indices of refraction nTM corresponding to the indices of refraction for said vertically oriented component TM of said optical signal in said poled electrooptic material;
• said poled electrooptic material defines an array of local TE indices of refraction nTE corresponding to the indices of refraction for said horizontally oriented component TE of said optical signal in said poled electrooptic material;
• said local TM indices nTM and said local TE indices nTE are each a function of a first electrooptic coefficient rPP for light parallel to a local component of said contoured electric field and a second electrooptic coefficient rIP for light perpendicular to a local component of said contoured electric field;
• a difference between said first said and second electrooptic coefficients rPP and rIP defines an optical birefringence of said poled electrooptic material;
• said local TM indices nTM collectively define a TM mode index of said waveguide;
• said local TE indices nTE collectively define a TE mode index of said waveguide;
• and
• said respective orientations of said contoured electric field and said poling contour are configured to compensate for said optical birefringence of said poled electrooptic material such that said TM mode index of said waveguide is substantially equal to said TE mode index of said waveguide.

An electrooptic waveguide for an optical signal, said optical signal including both a horizontally oriented component TE and a vertically oriented component TM, said waveguide comprising a plurality of control electrodes, an optical waveguide core, and a cladding optically coupled to said optical waveguide core, wherein:

• at least one of said core and said cladding comprises an electrooptic material poled along a poling contour;
• at least two of said control electrodes lie in a common edge plane;
• said control electrodes define an asymmetric configuration and are positioned to generate a contoured electric field across said poled electrooptic material;
• said optical waveguide core is offset from said common edge plane;
• said poled electrooptic material defines an array of local TM indices of refraction nTM corresponding to the indices of refraction for said vertically oriented component TM of said optical signal in said poled electrooptic material;
• said poled electrooptic material defines an array of local TE indices of refraction nTE corresponding to the indices of refraction for said horizontally oriented component TE of said optical signal in said poled electrooptic material;
• said local TM indices nTM and said local TE indices nTE are each a function of a first electrooptic coefficient rPP for light parallel to a local component of said contoured electric field and a second electrooptic coefficient rIP for light perpendicular to a local component of said contoured electric field;
• a difference between said first and second electrooptic coefficient rPP and rIP defines an optical birefringence of said poled electrooptic material;
• said local TM indices nTM collectively define a TM mode index of said waveguide;
• said local TE indices nTE collectively define a TE mode index of said waveguide;
• and
• said respective orientations of said contoured electric field and said poling contour are configured to compensate for said optical birefringence of said poled electrooptic material such that said TM mode index of said waveguide is substantially equal to said TE mode index of said waveguide.

An electrooptic waveguide for an optical signal, said optical signal including both a horizontally oriented component TE and a vertically oriented component TM, said waveguide consisting of a pair of control electrodes, an optical waveguide core, and a cladding optically coupled to said optical waveguide core, wherein:

• at least one of said core and said cladding comprises an electrooptic material poled along a poling contour defined in a selected cross section of said waveguide;
• said pair of control electrodes lie in parallel planes;
• said core is positioned between said parallel planes;
• at least one of said pair of control electrodes is limited to extend for a majority of its width along one side of said core in one of said parallel planes;
• said control electrodes define an asymmetric configuration and are positioned to generate a contoured electric field across said poled electrooptic material in said selected cross section;
• said optical waveguide core is offset from said parallel planes;
• said poled electrooptic material define an array of local TM indices of refraction nTM corresponding to the indices of refraction for said vertically oriented component TM of said optical signal in said poled electrooptic material;
• said poled electrooptic material defines an array of local TE indices of refraction nTE corresponding to the indices of refraction for said horizontally oriented component TE of said optical signal in said poled electrooptic material;
• said local TM indices nTM and said local TE indices nTE are each a function of a first electrooptic coefficient rPP for light parallel to a local component of said contoured electric field and a second electrooptic coefficient rIP for light perpendicular to a local component of said contoured electric field;
• a difference between said first and second electrooptic coefficients rPP and rIP defines an optical birefringence of said poled electrooptic material;
• said local TM indices nTM collectively define a TM mode index of said waveguide;
• said local TE indices nTE collectively define a TE mode index of said waveguide;
• and
• said respective orientations of said contoured electric field and said poling contour in said selected cross section are configured to compensate for said optical birefringence of said poled electrooptic material such that said TM mode index of said waveguide is substantially equal to said TE mode index of said waveguide.

An electrooptic waveguide for an optical signal, said optical signal including both a horizontally oriented component TE and a vertically oriented component TM, said waveguide comprising a plurality of control electrodes, an optical waveguide core, and a cladding optically coupled to said optical waveguide core, wherein:

• at least one of said core and said cladding comprises an electrooptic material poled along a poling contour,
• at least two of said control electrodes lie in a common edge plane;
• said core is positioned between said two control electrodes;
• said control electrodes are positioned to generate a contoured electric field across said poled electrooptic material;
• said poled electrooptic material defines an array of local TM indices of refraction nTM corresponding to the indices of refraction for said vertically oriented component TM of said optical signal in said poled electrooptic material;
• said poled electrooptic material defines an array of local TE indices of refraction nTE corresponding to the indices of refraction for said horizontally oriented component TE of said optical signal in said poled electrooptic material;
• said local TM indices nTM and said local TE indices nTE are each a function of a first electrooptic coefficient rPP for light parallel to a local component of said contoured electric field and a second electrooptic coefficient rIP for light perpendicular to a local component of said contoured electric field;
• a difference between said first and second electrooptic coefficients rPP and rIP defines an optical birefringence of said poled electrooptic material;
• said local TM indices nTM collectively define a TM mode index of said waveguide;
• said local TE indices nTE collectively define a TE mode index of said waveguide;
• and
• said respective orientations of said contoured electric field and said poling contour are configured to compensate for said optical birefringence of said poled electrooptic material such that said TM mode index of said waveguide is substantially equal to said TE mode index of said waveguide.

An electrooptic waveguide for an optical signal, said optical signal including both a horizontally oriented component TE and a vertically oriented component TM, said waveguide comprising three control electrodes, an optical waveguide core, and a cladding optically coupled to said optical waveguide core, wherein:

• at least one of said core and said cladding comprises an electrooptic material poled along a poling contour;
• said control electrodes are positioned to generate a contoured electric field across said poled electrooptic material;
• one of said three control electrodes has a reduced length dimension along a primary axis of propagation of said waveguide core relative to said first and second control electrodes;
• said poled electrooptic material defines an array of local TM indices of refraction nTM corresponding to the indices of refraction for said vertically oriented component TM of said optical signal in said poled electrooptic material;
• said poled electrooptic material defines an array of local TE indices of refraction nTE corresponding to the indices of refraction for said horizontally oriented component TE of said optical signal in said poled electrooptic material;
• said local TM indices nTM and said local TE indices nTE are each a function of a first electrooptic coefficient rPP for light parallel to a local component of said contoured electric field and a second electrooptic coefficient rIP for light perpendicular to a local component of said contoured electric field;
• a difference between said first and second electrooptic coefficients rPP and rIP defines an optical birefringence of said poled electrooptic material;
• said local TM indices nTM collectively define a TM mode index of said waveguide;
• said local TE indices nTE collectively define a TE mode index of said waveguide;
• said respective orientations of said contoured electric field and said poling contour are configured to compensate for said optical birefringence of said poled electrooptic material such that said TM mode index of said waveguide is substantially equal to said TE mode index of said waveguide;
• and
• said reduced length dimension is sufficient to contribute to said compensation of said optical birefringence of said poled electrooptic material.

An electrooptic waveguide for an optical signal, said optical signal including both a horizontally oriented component TE and a vertically oriented component TM, said waveguide comprising a plurality of control electrodes, an optical waveguide core, and an electrooptic cladding optically coupled to said optical waveguide core, wherein:

• said control electrodes are positioned to generate a contoured electric field across said cladding;
• said cladding is poled along a poling contour;
• said cladding defines an array of local TM indices of refraction nTM corresponding to the indices of refraction for said vertically oriented component TM of said optical signal in said cladding;
• said cladding defines an array of local TE indices of refraction nTE corresponding to the indices of refraction for said horizontally oriented component TE of said optical signal said cladding;
• said local TM indices nTM and said local TE indices nTE are each a function of a first electrooptic coefficient rPP for light parallel to a local component of said contoured electric field and a second electrooptic coefficient rIP for light perpendicular to a local component of said contoured electric field;
• a difference between said first and second electrooptic coefficients rPP and rIP defines an optical birefringence of an electrooptic cladding material defining said cladding;
• said local TM indices nTM collectively define a TM mode index of said waveguide;
• said local TE indices nTE collectively define a TE mode index of said waveguide;
• and
• said respective orientations of said contoured electric field and said poling contour are configured to compensate for said optical birefringence of said electrooptic cladding material such that said TM mode index of said waveguide is substantially equal to said TE mode index of said waveguide.