Tunable acoustic gradient index of refraction lens and system
A tunable acoustic gradient index of refraction (TAG) lens and system are provided that permit, in one aspect, dynamic selection of the lens output, including dynamic focusing and imaging. The system may include a TAG lens and at least one of a source and a detector of electromagnetic radiation. A controller may be provided in electrical communication with the lens and at least one of the source and detector and may be configured to provide a driving signal to control the index of refraction and to provide a synchronizing signal to time at least one of the source and the detector relative to the driving signal. Thus, the controller is able to specify that the source irradiates the lens (or detector detects the lens output) when a desired refractive index distribution is present within the lens, e.g. when a desired lens output is present.
1. A tunable acoustic gradient index of refraction lens, comprising:
a sealed enclosure comprising a casing, a first window disposed on a first side of the casing and sealed to the casing and a second window disposed on a second side of the casing opposite the first side and sealed to the casing, the first and second windows arranged to pass a light beam therethrough;
a refractive liquid disposed in the sealed enclosure that selectively changes its refractive index responsively to electrically controlled vibrational energy applied thereto; and
at least one vibrating element enclosed in the sealed enclosure in vibrational communication with the refractive liquid that delivers controlled vibrational energy to the refractive liquid to selectively alter the refractive index of the refractive liquid responsively to an electrical signal applied to the vibrating element.
2. The tunable acoustic gradient index of refraction lens according to claim 1 , wherein the casing comprises a tube with a consistent cross sectional shape.
3. The tunable acoustic gradient index of refraction lens according to claim 2 , wherein the cross sectional shape is one of a circle, an ellipse, an oval, a square, a rectangle, and a triangle.
4. The tunable acoustic gradient index of refraction lens according to claim 2 , wherein the tube has a central axis and is symmetrical about the axis.
5. The tunable acoustic gradient index of refraction lens according to claim 1 , wherein the refractive material is one of silicone and glycerol.
6. The tunable acoustic gradient index of refraction lens according to claim 1 , wherein the refractive material is more or less viscous than both silicone and glycerol.
7. The tunable acoustic gradient index of refraction lens according to claim 1 , wherein the vibrating element is a piezoelectric element.
8. The tunable acoustic gradient index of refraction lens according to claim 1 , further comprising a spacer element located between the vibrating element and the casing, wherein the spacer element is configured to center the vibrating element in the casing.
9. The tunable acoustic gradient index of refraction lens according to claim 8 , wherein the spacer element comprises a compliant cushioning material, and the vibrating element extends from an inner surface of the spacer element into the refractory material.
10. The tunable acoustic gradient index of refraction lens according to claim 1 , wherein the vibrating element is one of a plurality of vibrating elements.
11. The tunable acoustic gradient index of refraction lens according to claim 10 , wherein different electrical signals cause different vibrations in at least two of the vibrating elements.
12. The tunable acoustic gradient index of refraction lens according to claim 1 , wherein at least one of the windows has a curved surface.
13. The tunable acoustic gradient index of refraction lens according to claim 1 , wherein at least one of the windows has optical power.
14. The tunable acoustic gradient index of refraction lens according to claim 1 , wherein at least one of the windows operates as a filter or diffracting element.
15. The tunable acoustic gradient index of refraction lens according to claim 1 , wherein at least one of the windows is partially mirrored.
16. The tunable acoustic gradient index of refraction lens according to claim 1 , wherein the vibrating element is segmented into different zones to permit separate electrical signals to be delivered to and drive each zone.
17. A tunable acoustic gradient index of refraction lens, comprising:
a casing forming an enclosure with a refractive material disposed therein that selectively changes its refractive index responsively to electrically controlled vibrational energy applied thereto;
a first window disposed on a first side of the casing and a second window disposed on a second side of the casing opposite the first side, the first and second windows arranged to pass a light beam therethrough; and
at least one vibrating element in vibrational communication with the refractive material that delivers controlled vibrational energy to the refractive material to selectively alter the refractive index of the refractive material responsively to an electrical signal applied to the vibrating element;
wherein the vibrating element extends from a location proximate to an inner surface of the enclosure into the refractory material.
18. A tunable acoustic gradient index of refraction lens, comprising:
a sealed enclosure comprising a casing, a first window disposed on a first side of the casing and sealed to the casing and a second window disposed on a second side of the casing opposite the first side and sealed to the casing, the first and second windows arranged to pass a light beam therethrough;
a refractive liquid disposed in the sealed enclosure that selectively changes its refractive index responsively to electrically controlled vibrational energy applied thereto; and
at least one vibrating element enclosed in the sealed enclosure in vibrational communication with the refractive liquid that delivers controlled vibrational energy to the refractive liquid to selectively alter the refractive index of the refractive liquid responsively to an electrical signal applied to the vibrating element;
wherein the vibrating element extends from a location proximate to an inner surface of the enclosure into the refractory material.
19. A tunable acoustic gradient index of refraction lens, comprising:
a sealed enclosure comprising a casing, a first window disposed on a first side of the casing and sealed to the casing and a second window disposed on a second side of the casing opposite the first side and sealed to the casing, the first and second windows arranged to pass a light beam therethrough;
a refractive liquid disposed in the sealed enclosure that selectively changes its refractive index responsively to electrically controlled vibrational energy applied thereto; and
at least one vibrating element enclosed in the sealed enclosure in vibrational communication with the refractive liquid that delivers controlled vibrational energy to the refractive liquid to selectively alter the refractive index of the refractive liquid responsively to an electrical signal applied to the vibrating element;
wherein the vibrating element is located proximate to an inner surface of the enclosure.