High power faraday isolators and rotators using potassium terbium fluoride crystals
A high power Faraday isolator or rotator includes, at least one Faraday optical element, and a magnetic structure capable of generating a magnetic field within the at least one Faraday optical element. The at least one Faraday optical element comprises a Potassium Terbium Fluoride (KTF) crystal grown or manufactured along the [ 113 ] crystal orientation and which is oriented such that the light propagating through the Faraday isolator is within 2 degrees of the [ 113 ] crystal orientation.
1. A high power Faraday isolator or rotator comprising:
at least one Faraday optical element;
a magnetic structure capable of generating a magnetic field within said at least one Faraday optical element; and
wherein said at least one Faraday optical element comprises a Potassium Terbium Fluoride (KTF) crystal grown or manufactured along the [ 113 ] crystal orientation and oriented such that light propagating through the high power Faraday isolator or rotator is within 2 degrees of the [ 113 ] crystal orientation.
2. The isolator or rotator of claim 1 , wherein the at least one Faraday optical element comprises a single Faraday optical element.
3. The isolator or rotator of claim 1 , wherein the at least one Faraday optical element comprises a plurality of Faraday optical elements.
4. The isolator or rotator of claim 3 , wherein the plurality of Faraday optical elements comprises a plurality of discs.
5. The isolator or rotator of claim 4 , wherein the plurality of Faraday optical elements comprises six discs.
6. The isolator or rotator of claim 5 , wherein each disc rotates light 7.5 degrees for a total of 45 degrees of rotation after light passes through all six discs.
7. The isolator or rotator of claim 1 , wherein said KTF crystal does not exhibit thermal birefringence.
8. The isolator or rotator of claim 1 , wherein said KTF crystal does not exhibit radial stress birefringence.
9. The isolator or rotator of claim 1 , wherein said KTF crystal is insensitive to radial mounting stresses.
10. The isolator or rotator of claim 1 , wherein said KTF crystal is insensitive to radial growth and fabrication stresses.
11. A method for growing or manufacturing a crystal for a high power Faraday isolator or rotator, said method comprising:
Growing or manufacturing a Potassium Terbium Fluoride (KTF) crystal along the [ 113 ] crystal orientation.
12. The method of claim 11 , comprising creating a Faraday optical element from the grown or manufactured KTF crystal.
13. The method of claim 12 , wherein the Faraday optical element comprises a rod of [ 113 ] KTF crystal created from the grown or manufactured KTF crystal.
14. The method of claim 12 , wherein the Faraday optical element comprises a plurality of [ 113 ] KTF crystal discs created from the grown or manufactured KTF crystal.
15. The method of claim 14 , wherein the plurality of [ 113 ] KTF discs comprises six KTF discs.
16. The method of claim 15 , wherein each disc rotates light 7.5 degrees for a total of 45 degrees of rotation after light passes through all six [ 113 ] KTF discs.