Controlling beam intensity in an ophthalmic fiber optic illumination system using rotatable plate arrays

1. An ophthalmic illumination system comprising:

an optical fiber onto which a collimated light beam may be focused for transmission to an ophthalmic light probe;

a light attenuator including a pair of arrays positioned serially in a path of the collimated beam, the arrays movable in parallel in the path about a rotational axis orthogonal to the path and between the arrays; and

each array including a plurality of regularly spaced-apart parallel plates, the parallel plates of one array being non-parallel to the plates of the other array.

2. The system of claim 1 , wherein the parallel plates of one array are orthogonal to the plates of the other array.

3. The system of claim 1 , wherein the plates of one of the arrays are separated from one another by 1.5 millimeters, and a width of the plates is 2.3 millimeters.

4. The system of claim 1 , wherein each array passes an amount of the beam based on an angle of rotation of the arrays about the rotational axis.

5. The system of claim 1 , wherein the plates of each array block an amount of the beam based on an angle of rotation of the plates about the rotational axis.

6. The system of claim 1 , wherein the parallel plates of at least one of the arrays are at a 45-degree angle relative to the rotational axis.

7. An ophthalmic illumination system comprising:

a light source;

light collection optics through which a beam from the light source may be collimated and focused for transmission to an ophthalmic light probe;

a light attenuator in the light collection optics, the attenuator including a pair of parallel arrays positioned serially in a path of the collimated beam and rotatable together in the path about an axis orthogonal to the path and between the arrays; and

each array including a plurality of regularly spaced-apart parallel plates, the parallel plates of one array orthogonal to the plates of the other array.

8. The system of claim 7 , wherein an edge of each plate is presented to the beam when the attenuator is in a substantially fully open position.

9. The system of claim 7 , wherein the plates of one of the arrays are separated from one another by about 1.5 millimeters, and a width of the plates is 2.3 millimeters.

10. The system of claim 7 , wherein each array passes an amount of the beam based on an angle of rotation of the array.

11. The system of claim 7 , wherein the plates of each array blocks an amount of the beam based on an angle of rotation of the plates.

12. The system of claim 7 , wherein the parallel plates of the arrays are at 45-degree angles to the axis.