Electro-optic optical modulator devices and method of fabrication
A novel electro-optic optical modulator device and a related method for creating the novel optical modulator device are disclosed. In one embodiment, the novel optical modulator comprises a high index contrast optical waveguide, a mesa region, electrical modulation electrodes, RF transmission lines, and interconnection layers. The high index contrast optical waveguide comprises an electro-optic slab core region and a high index ridge core region. A mesa section which includes the core regions can be formed, and electrical modulation electrodes are placed on etched sidewalls of the mesa section to achieve electro-optical index modulation of the electro-optic slab core region. The RF transmission lines include RF electrodes that connected to the electrical modulation electrodes. The interconnection layers connect the modulation electrodes with the RF electrodes by using etched vias. The novel optical modulator can also incorporate foldable modulation arms for poling in the electro-optic slab core region.
1. A method for producing an optical modulator device, the method comprising the steps of:
depositing or growing a first low refractive index material layer as a cladding layer on top of a silicon base substrate;
depositing or transferring an electro-optic material layer on top of the first low refractive index material layer to form a slab core region;
depositing a high refractive index material layer on top of the slab core region and forming a waveguide by etching the high refractive index material layer;
forming an etch mask on the optical modulator device using a bilayer resist process;
etching the electro-optic material to access the first low refractive index material layer;
forming an electrode layer by depositing a metal and utilizing a lift-off process;
depositing a second low refractive index material layer;
etching vias in the second low refractive index material layer; and
forming an RF transmission line layer by electro-plating or another layer-forming method.
2. The method for producing the optical modulator device of claim 1 , further comprising a step of poling the optical modulator device when the waveguide and the RF transmission line layer incorporate one or more folded arms.
3. The method for producing the optical modulator device of claim 2 , wherein the one or more folded arms provide quasi-phase matching between an RF modulation field and an optical field in the optical modulator device.
4. The method for producing the optical modulator device of claim 1 , wherein the first low refractive index material layer and the second low refractive index material layer are each made of silicon dioxide or polymer, and wherein the electro-optic material layer is made of lithium niobate or lithium tantalite.
5. The method for producing the optical modulator device of claim 1 , wherein the high refractive index material layer is made of silicon nitride, aluminum nitride, tantalum pentoxide, or niobium pentoxide, with a refractive index approximately between 2 and 2.3.
6. The method for producing the optical modulator device of claim 1 , wherein a modulation arm of a Mach-Zehnder optical modulator is produced by the steps recited in the method.
7. The method for producing the optical modulator device of claim 1 , wherein a modulation arm of a micro-ring modulator is produced by the steps recited in the method.
8. The method for producing the optical modulator device of claim 1 , wherein a dual parallel Mach-Zehnder optical modulator is produced by the steps recited in the method.
9. The method for producing the optical modulator device of claim 1 , wherein a resonance-enhanced Mach-Zehnder optical modulator is produced by the steps recited in the method.
10. The method for producing the optical modulator device of claim 1 , wherein a dual parallel resonance-enhanced Mach-Zehnder optical modulator is produced by the steps recited in the method.
11. The method for producing the optical modulator device of claim 1 , wherein a tunable array waveguide grating device is produced by the steps recited in the method.
12. The method for producing the optical modulator device of claim 1 , wherein a photonic assisted analog to digital conversion device is produced by the steps recited in the method.