System and method for tissue treatment

1. A cooling element comprising:

a frame comprising one or more datums that define a datum plane;

a first window comprising a first proximal surface and a first distal surface, the first window sealed to the frame;

a second window sealed to the frame and arranged at an angle less than 10 milliradians relative to the datum plane, the second window comprising a second proximal surface and a second distal surface, wherein the second window is configured to contact a target tissue or a tissue adjacent to the target tissue via the second distal surface; and

a coolant chamber located between the first distal surface of the first window and the second proximal surface of the second window and configured to receive a coolant, wherein the first window, the second window and the coolant chamber are configured to receive an electromagnetic radiation (EMR) and transmit a portion of the received EMR to the target tissue.

2. The cooling element of claim 1 , wherein the cooling chamber includes a port configured to direct a coolant from a coolant flow source to the coolant chamber.

3. The cooling element of claim 1 , wherein the first window is sealed to the frame via a first seal, and the second window is sealed to the frame vis a second seal.

4. The cooling element of claim 3 , wherein the first seal includes one or more of an adhesive, a weld, a solder, a braze, a polymer, and an elastomer.

5. The cooling element of claim 1 , wherein the first window has a first thermal effusivity; and, the second window has a second thermal effusivity that is greater than or equal to the first thermal effusivity.

6. The cooling element of claim 1 , wherein the first window has a first thickness and the second window has a second thickness that is less than or equal to the first thickness.

7. The cooling element of claim 1 , wherein the first window has a first thickness, the second window has a second thickness, the cooling chamber has a third thickness, and the sum of the first thickness, the second thickness, and the third thickness is less than 5 mm.

8. The cooling element of claim 1 , wherein the second distal surface of the second window has a shape that comprises one or more of plano, convex, and concave.

9. The cooling element of claim 1 , further comprising a fastener, wherein the fastener is configured to affix the second window to the frame.

10. The cooling element of claim 9 , wherein the fastener comprises at least one of a screw, a clamp, a snap, a retaining ring, and a tab.

11. The cooling element of claim 1 , wherein the second window comprises at least one of sapphire, quartz, and diamond.

12. The cooling element of claim 1 , wherein the first window is arranged at a second angle less than or equal to 10 milliradians relative to the second window.

13. The cooling element of claim 1 , wherein the coolant comprises at least one of propylene-glycol and water.

14. The cooling element of claim 1 , wherein the EMR has a wavelength in a range of 200 nm to 4,000 nm.

15. The cooling element of claim 1 , wherein the EMR exhibits a convergence according to a numerical aperture greater than or equal to 0.3.

16. A method comprising:

transmitting an electromagnetic radiation (EMR) through a cooling element, wherein the cooling element comprises:

a frame comprising one or more datums that define a datum plane;

a first window comprising a first proximal surface and a first distal surface, the first window sealed to the frame;

a second window sealed to the frame and arranged at an angle less than 10 milliradians relative to the datum plane, the second window comprising a second proximal surface and a second distal surface;

a coolant chamber located between the first distal surface of the first window and the second proximal surface of the second window; and

contacting, using the second distal surface of the second window, a target tissue or a tissue adjacent to the target tissue.

17. The method of claim 16 , further comprising focusing the EMR to a focal region within the target tissue.

18. The method of claim 17 , wherein the EMR exhibits a convergence according to a numerical aperture greater than or equal to 0.3.

19. The method of claim 16 , wherein the cooling chamber includes a port configured to direct a coolant from a coolant flow source to the coolant chamber.

20. The method of claim 16 , wherein the first window is sealed to the frame via a first seal, and the second window is sealed to the frame via a second seal.

21. The method of claim 20 , wherein the first seal includes one or more of an adhesive, a weld, a solder, a braze, a polymer, and an elastomer.

22. The method of claim 16 , wherein the first window has a first thermal effusivity, and the second window has a second thermal effusivity that is greater than or equal to the first thermal effusivity.

23. The method of claim 16 , wherein the first window has a first thickness and the second window has a second thickness that is less than or equal to the first thickness.

24. The method of claim 16 , wherein the first window has a first thickness; the second window has a second thickness; the cooling chamber has a third thickness; and, the sum of the first thickness, the second thickness, and the third thickness is less than 5 mm.

25. The method of claim 16 , wherein the second distal surface of the second window has a shape that comprises one or more of plano, convex, and concave.

26. The method of claim 16 , wherein the cooling element further comprises a fastener, wherein the fastener is configured to affix the second window to the frame.

27. The method of claim 16 , wherein the second window comprises at least one of sapphire, quartz, and diamond.

28. The method of claim 16 , wherein the first window is arranged at a second angle less than or equal to 10 milliradians relative to the second window.

29. The method of claim 16 , wherein the EMR has a wavelength in a range of 200 nm to 4,000 nm.

30. The method of claim 16 , further comprising receiving a coolant into the coolant chamber.