Method and structure for nonlinear optics
A nonlinear optical crystal having a chemical formula of Y i La j Al k B 16 O 48 , where 2.8≦i≦3.2, 0.8≦j≦1.2, i and j sum to about four, and k is about 12 is provided. The nonlinear optical crystal is useful for nonlinear optical applications including frequency conversion. Nonlinear optical crystals in a specific embodiment are characterized by UV blocking materials (e.g., some transition metals and lanthanides) at concentrations of less than 1,000 parts per million, providing high transmittance over portions of the UV spectrum (e.g., 175-360 nm).
1. A composition of matter having the general formula comprising Y i La j Al k B 16 O 48 , where 2.8≦i≦3.2, 0.8≦j≦1.2, i and j sum to about four, and k is about 12.
2. The composition of matter of claim 1 wherein 2.96≦i≦3.08.
3. The composition of matter of claim 2 wherein i is about 3.
4. The composition of matter of claim 1 wherein 0.92≦j≦1.04.
5. The composition of matter of claim 4 wherein j is about 1.
6. The composition of matter of claim 1 wherein a concentration of elements with atomic numbers 22-30, 40-48, and 72-80 in the composition is less than 1,000 parts per million.
7. The composition of matter of claim 1 wherein a concentration of elements with atomic numbers 58-70 in the composition is less than 1,000 parts per million.
8. The composition of matter of claim 1 wherein the composition of matter is a nonlinear crystal characterized by an optical transmittance of greater than 0.7 at 250 nm.
9. A method of growing one or more nonlinear crystals of a composition, the method comprising:
providing a set of constituent components of the composition including an yttrium source and an aluminum source;
mixing the set of constituent components of the composition with a lanthanum source and a boron source to form a component mixture;
heating the component mixture to a predetermined temperature, thereby forming a resultant melt;
cooling the resultant melt; and
forming the one or more nonlinear crystals of the composition as a precipitate from the resultant melt, wherein the one or more nonlinear crystals comprise Y i La j Al k B 16 O 48 , where 2.8≦i≦3.2, 0.8≦j≦1.2, i and j sum to about four, and k is about 12.
10. The method of claim 9 wherein the set of constituent components is characterized by a predetermined amount of nutrients and a predetermined amount of solvents, wherein a mole ratio of lanthanum to yttrium is in a range of more than 1.5:1 and wherein a mole ratio of the predetermined amount of nutrients to the predetermined amount of solvents is in a range of 1:1 to 1:5.
11. The method of claim 9 further comprising maintaining the resultant melt at the predetermined temperature for a predetermined time.
12. The method of claim 9 wherein the predetermined temperature is approximately 1500° K.
13. The method of claim 9 wherein cooling the resultant melt is performed at a temperature rate of less than 20° K/hour.
14. The method of claim 9 wherein the set of constituent components of the composition comprise an yttrium source and an aluminum source.
15. The method of claim 14 wherein yttrium source comprises yttrium oxide and the aluminum source comprises aluminum oxide.
16. The method of claim 9 wherein the lanthanum source comprises lanthanum oxide and the boron source comprises at least one of boron oxide or boric acid.
17. A nonlinear optical crystal having a chemical formula of Y i La j Al k B 16 O 48 , where 2.8≦i≦3.2, 0.8≦j≦1.2, i and j sum to about four, and k is about 12.
18. The nonlinear optical crystal of claim 17 wherein the nonlinear optical crystal is associated with the trigonal crystal class of space group R32.
19. The nonlinear optical crystal of claim 17 wherein the nonlinear optical crystal is characterized by a volume greater than about 1.0 mm 3 .
20. The nonlinear optical crystal of claim 17 wherein a concentration of elements with atomic numbers 22-30, 40-48, 58-70, and 72-80 is less than about 1,000 parts per million.