High harmonics generation of light

1. A method of generating light, comprising irradiating a substance with first optical field of a first frequency and second optical field of a second frequency,

wherein the ratio between said second frequency and said first frequency is non-integer and wherein said second frequency is higher than a cutoff frequency of a harmonics generation spectrum characterizing the interaction of said substance with said first optical field.

2. The method of claim 1 , wherein said first frequency is in the infrared range.

3. The method of claim 1 , wherein said second frequency is in the ultraviolet range.

4. The method of claim 1 , wherein said second frequency is in the extreme ultraviolet range.

5. The method of claim 1 , wherein said second frequency is in the X-ray range.

6. The method of claim 1 , wherein said first optical field has an intensity which is substantially higher than the intensity of said second optical field.

7. The method of claim 1 , wherein said first optical field has an intensity which approximately equals the intensity of said second optical field.

8. The method of claim 1 , wherein said first optical field has an intensity which is lower than the intensity of said second optical field.

9. The method of claim 1 , wherein a combination of said first optical field and said second optical field results in emission of a harmonics generation spectrum from said substance, said emitted harmonics generation spectrum having at least one harmonic which is enhanced relative to a respective harmonic of the harmonics generation spectrum that would have been emitted had said substance been irradiated solely by said first optical field.

10. Apparatus for generating light, comprising a substance, a first light source for generating in the direction of said substance first optical field of a first frequency and a second light source for generating in the direction of said substance second optical field of a second frequency, wherein the ratio between said second frequency and said first frequency is non-integer and wherein said second frequency is higher than a cutoff frequency of a harmonics generation spectrum characterizing the interaction of said substance with said first optical field.

11. An imaging system for imaging an object or a scene, comprising the apparatus of claim 10 arranged to direct light to the object or scene, and an imager configured for imaging the object or scene based on light emitted thereby, reflected therefrom or transmitted therethrough.

12. A spectroscopy system for determining the concentration of analyte in a sample, comprising the apparatus of claim 10 arranged to direct light to the sample, and a light detector configured for detecting light emitted by, reflected from or transmitted through the sample.

13. A lithography system, comprising the apparatus of claim 10 arranged to direct a light beam to a substrate to form patterns thereon, and alignment mechanism for aligning said substrate with said light beam.

14. A micro-machining system, comprising the apparatus of claim 10 .

15. The apparatus of claim 10 , wherein said first frequency is in the infrared range.

16. The apparatus of claim 10 , wherein said second frequency is in the ultraviolet range.

17. The apparatus of claim 10 , wherein said second frequency is in the extreme ultraviolet range.

18. The apparatus of claim 10 , wherein said second frequency is in the X-ray range.

19. The apparatus of claim 10 , wherein said first optical field has an intensity which is substantially higher than the intensity of said second optical field.

20. The apparatus of claim 10 , wherein said first optical field has an intensity which approximately equals the intensity of said second optical field.

21. The apparatus of claim 10 , wherein said first optical field has an intensity which is lower than the intensity of said second optical field.

22. The apparatus of claim 10 , wherein a combination of said first optical field and said second optical field results in emission of a harmonics generation spectrum from said substance, said emitted harmonics generation spectrum having at least one harmonic which is enhanced relative to a respective harmonic of the harmonics generation spectrum that would have been emitted had said substance been irradiated solely by said first optical field.

23. A method of generating light, comprising irradiating a substance with first optical field of a first frequency and second optical field of a second frequency, wherein the ratio between said second frequency and said first frequency is an integer and wherein the second frequency is higher than a cutoff frequency of a harmonics generation spectrum characterizing the interaction of said substance with said first optical field.

24. The method of claim 23 , wherein said first frequency is in a range selected from the group consisting of the infrared range, the ultraviolet range, the extreme ultraviolet range, and the X-ray range.

25. The method of claim 23 , wherein said first optical field has an intensity which is substantially higher than the intensity of said second optical field.

26. The method of claim 23 , wherein said first optical field has an intensity which approximately equals the intensity of said second optical field.

27. The method of claim 23 , wherein said first optical field has an intensity which is lower than the intensity of said second optical field.

28. The method of claim 23 , wherein a combination of said first optical field and said second optical field results in emission of a harmonics generation spectrum from said substance, said emitted harmonics generation spectrum having at least one harmonic which is enhanced relative to a respective harmonic of the harmonics generation spectrum that would have been emitted had said substance been irradiated solely by said first optical field.

29. Apparatus for generating light, comprising a substance, a first light source for generating in the direction of said substance first optical field of a first frequency and a second light source for generating in the direction of said substance second optical field of a second frequency, wherein the ratio between said second frequency and said first frequency is an integer, and wherein said second frequency is higher than a cutoff frequency of a harmonics generation spectrum characterizing the interaction of said substance with said first optical field.

30. An imaging system for imaging an object or a scene, comprising the apparatus of claim 29 arranged to direct light to the object or scene, and an imager configured for imaging the object or scene based on light emitted thereby, reflected therefrom or transmitted therethrough.

31. A spectroscopy system for determining the concentration of analyte in a sample, comprising the apparatus of claim 29 arranged to direct light to the sample, and a light detector configured for detecting light emitted by, reflected from or transmitted through the sample.

32. A lithography system, comprising the apparatus of claim 29 arranged to direct a light beam to a substrate to form patterns thereon, and alignment mechanism for aligning said substrate with said light beam.

33. A micro-machining system, comprising the apparatus of claim 29 .

34. The apparatus of claim 29 , wherein said first frequency is in a range selected from the group consisting of the infrared range, the ultraviolet range, the extreme ultraviolet range, and the X-ray range.

35. The apparatus of claim 29 , wherein said first optical field has an intensity which is substantially higher than the intensity of said second optical field.

36. The apparatus of claim 29 , wherein said first optical field has an intensity which approximately equals the intensity of said second optical field.

37. The apparatus of claim 29 , wherein said first optical field has an intensity which is lower than the intensity of said second optical field.

38. The apparatus of claim 29 , wherein a combination of said first optical field and said second optical field results in emission of a harmonics generation spectrum from said substance, said emitted harmonics generation spectrum having at least one harmonic which is enhanced relative to a respective harmonic of the harmonics generation spectrum that would have been emitted had said substance been irradiated solely by said first optical field.

39. A method of generating light, comprising irradiating a substance with first optical field of a first frequency and second optical field of a second frequency, wherein said first optical field has an intensity which is lower or approximately equal the intensity of said second optical field, and wherein said second frequency is higher than a cutoff frequency of a harmonics generation spectrum characterizing the interaction of said substance with said first optical field.

40. The method of claim 39 , wherein said first frequency is in a range selected from the group consisting of the infrared range, the ultraviolet range, the extreme ultraviolet range, and the X-ray range.

41. The method of claim 39 , wherein a combination of said first optical field and said second optical field results in emission of a harmonics generation spectrum from said substance, said emitted harmonics generation spectrum having at least one harmonic which is enhanced relative to a respective harmonic of the harmonics generation spectrum that would have been emitted had said substance been irradiated solely by said first optical field.

42. Apparatus for generating light, comprising a substance, a first light source for generating in the direction of said substance first optical field of a first frequency and a second light source for generating in the direction of said substance second optical field of a second frequency, wherein said first optical field has an intensity which is lower or approximately equal the intensity of said second optical field, and wherein said second frequency is higher than a cutoff frequency of a harmonics generation spectrum characterizing the interaction of said substance with said first optical field.

43. An imaging system for imaging an object or a scene, comprising the apparatus of claim 42 arranged to direct light to the object or scene, and an imager configured for imaging the object or scene based on light emitted thereby, reflected therefrom or transmitted therethrough.

44. A spectroscopy system for determining the concentration of analyte in a sample, comprising the apparatus of claim 42 arranged to direct light to the sample, and a light detector configured for detecting light emitted by, reflected from or transmitted through the sample.

45. A lithography system, comprising the apparatus of claim 42 arranged to direct a light beam to a substrate to form patterns thereon, and alignment mechanism for aligning said substrate with said light beam.

46. A micro-machining system, comprising the apparatus of claim 42 .

47. The apparatus of claim 42 , wherein said first frequency is in a range selected from the group consisting of the infrared range, the ultraviolet range, the extreme ultraviolet range, and the X-ray range.

48. The apparatus of claim 42 , wherein a combination of said first optical field and said second optical field results in emission of a harmonics generation spectrum from said substance, said emitted harmonics generation spectrum having at least one harmonic which is enhanced relative to a respective harmonic of the harmonics generation spectrum that would have been emitted had said substance been irradiated solely by said first optical field.