Electro-optic crystal, diffraction-based, beam-steering element
View Patent ↗A beam-steering element made of a more optically-active material, potassium tantalate niobate, with an improved diffraction efficiency, having a plurality of electrode layers and one electro-optic crystal layer interposed between every two adjacent electrode layers. Each electro-optic crystal layer and the electrode layer adjacent thereto have an aspect ratio of about 1:1. The electrode layers and the electro-optic crystal layers are interposed between two substrates. Preferably, the substrates are transparent to an incoming beam to be modulated by the electro-optic crystal layer.
1. A method of fabricating an agile beam-steering element, comprising:
providing a first substrate and a second substrate;
forming a first array of electrodes on each of the first and second substrates, the electrodes of each first array are spaced from each other by a gap;
filling the gaps between the electrodes by an insulation material;
optically contacting an electro-optic crystal layer on each array of electrodes;
polishing the electro-optic crystal layer;
forming a second array of electrodes on the electro-optic crystal layer of one of the first and second substrates;
aligning the first and second arrays of electrodes with each other; and
connecting the second array of electrodes to the electro-optic crystal layer of the other substrate.
2. The method of claim 1 , wherein the first and second substrates include transparent substrates.
3. The method of claim 1 , wherein the electrodes are transparent.
4. The method of claim 1 , further comprising forming the electro-optical layers of potassium tantalate niobate.
5. The method of claim 1 , further comprising filling gaps between the electrodes of each array with an insulation layer.
6. The method of claim 1 , further comprising filling the gaps with silicon oxide.
7. The method of claim 1 , further comprising polishing the electro-optic crystal layer to obtain an aspect ratio of about 1:1 between the electro-optic crystal and the first and second arrays of electrodes.
8. The method of claim 1 , further comprising forming the first array and the second array of electrodes with a thickness of about 1 micron.
9. The method of claim 1 , further comprising forming the electro-optic crystal layers with a thickness of about 1.5 microns.
10. The method of claim 1 , further comprising forming a mirror layer on one of the first and second substrates.
11. A method of fabricating an agile beam-steering element, comprising:
forming two electro-optic modulation modules, wherein each of the modulation modules is fabricated by the process comprising:
providing a first substrate and a second substrate;
forming a first number of electrode layers and a second number of electro-optic modulation layers alternately interposed between the first and second substrates, wherein the first number is larger than the second number by one; and
mating the modulation modules together by attaching the second substrates to each other.
12. The method of claim 11 , wherein the second substrates are thinner than the first substrate.
13. The method of claim 11 , wherein the second substrates have a thickness substantially the same as that of one of the electro-optic modulation layers.
14. The method of claim 11 , wherein the first and second substrates and the electrode layers are transparent to an incoming beam to be modulated by the electro-optic modulation layers.
15. The method of claim 11 , wherein each of the electrode layers includes an array of electrodes spaced with each other by a gap.
16. The method of claim 15 , wherein the gaps are filled by an insulation material.
17. The method of claim 15 , further comprising forming the electro-optic modulation layers from potassium tantalate niobate.