Waveguide structure

An optical structure comprising a waveguide structure (1) having a core (2) comprising a layer of at least an electro-optic dielectric material (3), a layer of at least a semiconductor material (4) provided below the electro-optic material (3) and a layer of at least a semiconductor material (5) provided above the electro-optic material (3), and electrodes (6, 6′, 7, 8), that are configurable for voltage application, wherein:

• the electro-optic dielectric material (3) has a Pockets tensor containing at least one non-vanishing element rij where i≠j, and the electrodes (6, 6′, 7, 8) comprise respective sets of electrodes (6, 6′, 7, 8) comprising a set of electrodes (6, 6′) that are provided substantially in direct contact with the electro-optic dielectric material (3), and a further set of electrodes (7, 8) comprising at least an electrode (7) provided substantially in direct contact with the semiconductor material (4) below the electro-optic material (3) and at least an electrode (8) provided substantially in direct contact with the semiconductor material (5) above the electro-optic material (3), wherein the respective sets of electrodes (6, 6′, 7, 8) are configurable to apply in the electro-optic material (3), when the waveguide structure (1) is in use, at least a substantially horizontal electrical field (11) and at least a substantially vertical electrical field (12) that are orientated substantially perpendicular relative to each other.

A method for fabricating a waveguide structure (1) comprising the steps of:

• providing a core (2) comprising a layer of at least an electro-optic dielectric material (3), a layer of at least a semiconductor material (4) below the electro-optic material (3) and a layer of at least a semiconductor material (5) above the electro-optic material (3), and providing electrodes (6, 6′, 7, 8) that are configurable for voltage application, wherein:
• the electro-optic dielectric material (3) is selected to have a Pockels tensor containing at least one non-vanishing element rij where and i≠j the electrodes (6, 6′, 7, 8) are provided as comprising respective sets of electrodes (6, 6′, 7, 8) that comprise a set of electrodes (6) that are provided substantially in direct contact with the electro-optic dielectric material (3) and a set of electrodes (7, 8) comprising at least an electrode (7) that is provided substantially in direct contact with the semiconductor material (4) provided below the electro-optic material (3) and at least an electrode (8) that is provided substantially in direct contact with the semiconductor material (5) provided above the electro-optic material (3), wherein the respective sets of electrodes (6, 6′, 7, 8) are configurable to apply in the electro-optic material (3), when the waveguide structure (1) is in use, at least a substantially horizontal electrical field (11) and at least a substantially vertical electrical field (12) that are orientated substantially perpendicular relative to each other.