High-brightness laser-pumped plasma light source
The light source contains a chamber with a region of radiating plasma sustained by a focused beam of a CW laser. The chamber consists of a tube, a bottom and a cap. The cap is arranged for filling the chamber with gas. The tube and bottom are made from an optically transparent material. The bottom is arranged for input into the chamber of the CW laser beam and pulsed laser beams used for the plasma ignition, while the tube is arranged for exit of the output beam of plasma radiation. Preferably shape of the tube is arranged for reducing aberrations which distort a path of rays of plasma radiation passing through the tube wall. The technical result consists in creating electrodeless high-brightness broadband light sources with the high spatial and power stability, and in providing an ability to collect plasma radiation in a spatial angle of more than 9 sr.
1. A laser-pumped plasma light source, comprising: a chamber filled with high-pressure gas, a region of radiating plasma sustained in the chamber by a focused beam of a continuous wave (CW) laser; at least one output beam of plasma radiation exiting the chamber, a means for plasma ignition, wherein
the means for plasma ignition is a pulsed laser system generating at least one pulsed laser beam focused in the chamber;
the chamber consists of a tube, a bottom and a cap; one end of the tube is hermetically connected to the bottom, while the other end of the tube is hermetically connected to the cap;
the cap is arranged for filling the chamber with the gas;
the tube and the bottom of the chamber are made from an optically transparent material; the bottom is arranged for introducing the focused beam of the CW laser and each pulsed laser beam into the chamber, and the tube is arranged for exit of the output beam of plasma radiation from the chamber.
2. The light source according to claim 1 , wherein a shape of the tube is configured for reducing aberrations which distort a path of the output beam of plasma radiation passing through a tube wall.
3. The light source according to claim 1 , wherein at least a portion of the tube has an axis of symmetry, a center of symmetry and a barrel or a toroidal shape of an external surface, while the radiating plasma region is located at the center of symmetry of the tube.
4. The light source according to claim 1 , wherein an internal surface of the tube is cylindrical.
5. The light source according to claim 4 , wherein a radius of the internal surface of the tube is less than 5 mm, preferably not more than 3 mm.
6. The light source according to claim 1 , wherein the tube, excluding its end parts, is configures for exit of the output beam of plasma radiation from the chamber in all azimuths.
7. The light source according to claim 1 , wherein the output beam of plasma radiation exits the chamber in a solid angle of not less than 9 sr.
8. The light source according to claim 1 , wherein the beam of the CW laser is focused in the chamber by means of an optical system comprising the chamber bottom and a focusing optical element with a surface minimizing total aberrations of the optical system.
9. The light source according to claim 8 , wherein the focusing optical element is an aspherical lens.
10. The light source according to claim 1 , wherein the focused beam of the CW laser is directed into the chamber vertically upwards.
11. The light source according to claim 1 , wherein a part of the cap is designed as a concave spherical mirror with a center in the region of the radiating plasma region and a cap radius is less than 5 mm.
12. The light source according to claim 1 , wherein the tube and the bottom are made from a material belonging to a group of sapphire, leuco sapphire, fused quartz, crystalline quartz.
13. The light source according to claim 1 , wherein the tube and the bottom are sealed using a glass cement.
14. The light source according to claim 1 , wherein the tube and the bottom are made as a whole from a single piece of material.
15. The light source according to claim 1 , wherein the tube and the cap are sealed by means of brazing.
16. The light source according to claim 1 , wherein the cap is equipped with a gas port arranged for controlling a pressure and a composition of the gas in the chamber.
17. The light source according to claim 1 , wherein the cap is equipped with a heater.
18. The light source according to claim 1 , wherein the means for plasma ignition is a solid-state laser system generating in Q-switching mode and in free-running mode two pulsed laser beams focused into the chamber.
19. The light source according to claim 1 with three or more output beams of plasma radiation.
20. The light source according to claim 1 , wherein the chamber is located in an external bulb.