초록 ▼

Preferred embodiments of the invention provide for methods and systems of 2D spectroscopy using ultrafast, first light and second light beams and a CCD array detector. A cylindrically-focused second light beam interrogates a target that is optically interactive with a frequency-dispersed excitation

Preferred embodiments of the invention provide for methods and systems of 2D spectroscopy using ultrafast, first light and second light beams and a CCD array detector. A cylindrically-focused second light beam interrogates a target that is optically interactive with a frequency-dispersed excitation (first light) pulse, whereupon the second light beam is frequency-dispersed at right angle orientation to its line of focus, so that the horizontal dimension encodes the spatial location of the second light pulse and the first light frequency, while the vertical dimension encodes the second light frequency. Differential spectra of the first and second light pulses result in a 2D frequency-frequency surface equivalent to double-resonance spectroscopy. Because the first light frequency is spatially encoded in the sample, an entire surface can be acquired in a single interaction of the first and second light pulses.

대표청구항 ▼

The invention claimed is: 1. A method for converting a frequency of light comprising: frequency-dispersing a light signal in a first axial direction; frequency-dispersing the frequency dispersed light signal in a second axial direction that is different from the first axial direction to form a two-

The invention claimed is: 1. A method for converting a frequency of light comprising: frequency-dispersing a light signal in a first axial direction; frequency-dispersing the frequency dispersed light signal in a second axial direction that is different from the first axial direction to form a two-dimensional frequency dispersed light signal; directing the two-dimensional frequency-dispersed light signal and a second light signal such that the two-dimensional frequency dispersed light signal spatially overlaps the second light signal on a frequency conversion element to generate a frequency converted signal; and detecting a frequency converted two dimensional spectrum from the frequency conversion element with a two dimensional detector array. 2. The method of claim 1, further comprising frequency-dispersing the light signal in a first direction with a first grating. 3. The method of claim 1, further comprising detecting a frequency converted image of a material positioned to receive the frequency dispersed light signal with the detector array. 4. The method of claim 3, further comprising: detecting the image and generating spectral data; and processing the spectral data with a data processor. 5. The method of claim 3, further comprising detecting the image with a charge coupled device (CCD). 6. The method of claim 3, further comprising controlling a light source and the detector with an interface controller. 7. The method of claim 1, further comprising generating the second light signal with a pulse duration in the range between 1 femtosecond and 10 picoseconds. 8. The method of claim 1, further comprising generating the light signal having a frequency in an infrared range. 9. The method of claim 1, further comprising converting an infrared frequency to a higher frequency with a crystal. 10. The method of claim 9, further comprising providing a crystal having a non-linear optical response such as KNbO3 or MgO:LiNbO3. 11. The method of claim 1, further comprising directing a second broadband light signal onto an optical path in which the frequency conversion element is positioned. 12. The method of claim 1, further comprising directing the second light signal to the frequency conversion element with a first reflective element. 13. The method of claim 1, further comprising directing the second light pulse after the frequency conversion element from the optical path with a second reflective element. 14. The method of claim 13, further comprising filtering the frequency converted signal with a bandpass filter having a visible cutoff wavelength. 15. The method of claim 14, wherein the reflecting element has a reflective cutoff wavelength greater than the bandpass filter. 16. The method of claim 1, wherein the method further comprises providing a spectrometer and calibrating the spectrometer with an interferometer. 17. The method of claim 1, further comprising simultaneously detecting a plurality of infrared signals. 18. The method of claim 17, further comprising forming a spectroscopic image with the plurality of detected signals. 19. The method of claim 1, further comprising monitoring a chemical process. 20. The method of claim 1, further comprising monitoring an optical communication signal such as a fiber optic signal. 21. The method of claim 1, further comprising using an objective lens or cylindrical lens system to direct the first light pulse onto a material for spectroscopic imaging. 22. An apparatus for altering an infrared light pulse, comprising: a first light source; a first frequency-dispersing element optically coupled to the first light source that frequency disperses light in a first direction; a second frequency-dispersing device that disperses light from the first frequency-dispersing element in a second direction; a frequency conversion element; a second light source optically coupled to the frequency-conversion element, with the first frequency-dispersing element being positioned relative to the second frequency dispersing device to couple frequency dispersed light to the frequency-conversion element; and a detector that detects frequency converted light from the frequency conversion element. 23. The apparatus of claim 22, wherein the first frequency-dispersing device comprises a grating. 24. The apparatus of claim 22, further comprising a detector optically coupled to the frequency conversion element. 25. The apparatus of claim 22, wherein the second light pulse source is a source for light pulses in the range between 1 femtosecond and 10 picoseconds in duration. 26. The apparatus of claim 22, wherein the first light source emits light having a frequency in an infrared range. 27. The apparatus of claim 22, wherein the frequency-conversion element is a non-linear crystal such as KNBO3 or MgO:LiNbO3. 28. The apparatus of claim 22, wherein the frequency-dispersing device is a prism or curved grating. 29. The apparatus of claim 22 wherein the first frequency dispersing element disperses light in a first direction such that different frequencies are spatially dispersed across different regions of a material and the second frequency dispersing element that disperses light from the material in a second direction that is different from the first direction. 30. The apparatus of claim 29 wherein the first direction is orthogonal to the second direction. 31. The apparatus of claim 29 wherein the first element is a first grating and the second element is a second grating. 32. The apparatus of claim 29 wherein the apparatus device forms a two dimensional spectroscopic image that is frequency converted and detected by a two dimensional detector array. 33. The apparatus of claim 29 wherein light from the first dispersing element is directed onto a light path have a sample to be measured, the sample interacting with the light to form a sampled light signal that is coupled to the second dispersing element to form a spectroscopic image that is. 34. The apparatus of claim 33 further comprising coupling a third non-dispersed light signal to the sample. 35. The apparatus of claim 34 wherein the third signal comprises light separated from a light beam incident on the first dispersing element with a beamsplitter. 36. The apparatus of claim 34 further comprising a lens to couple the third light signal onto the sample along the light path with light from the first dispersing elements. 37. The apparatus of claim 33 further comprising a first spherical mirror reflecting light from the sample onto the second dispersing element and a second spherical mirror reflecting light onto the frequency conversion element. 38. The apparatus of claim 22 wherein light from the frequency dispersing element directed on a second optical path that overlaps light from the second light source at the frequency conversion element. 39. The apparatus of claim 38 further comprising a first beamsplitter and a second beamsplitter coupling light from the second light source onto and away from the second optical path. 40. A method of two dimensional spectroscopic imaging comprising: spectrally dispersing a light signal in a first direction; optically coupling the spectrally dispersed light onto a material such that different frequencies are incident on different regions of the material; optically coupling a second light signal onto the material; spectrally dispersing light from the material in a second direction; and detecting a two dimensional spectroscopic image of the dispersed light from the material with a two dimensional detector array. 41. The method of claim 40 further comprising: detecting the second light signal by imaging said signal; differentially detecting an array image with and without the first light signal; and producing a 2D spectrum that correlates a frequency of the first light signal and a frequency of the second light signal. 42. The method of claim 40 further comprising: coupling energy into the material with the first light signal to excite one or more of properties, energy levels, aspects, bonds, orbitals and characteristics of the material; and coupling the material with the second light signal at detectable frequencies such that the one or more of properties, energy levels, aspects, bonds, orbitals and characteristics of the material that have been excited by the optical interaction with the first light signal are detected in the 2D spectrum. 43. The method of claim 40, further comprising: spectrally dispersing the first light signal in a first plane; focusing the second light signal in the first plane; collecting the second light signal after the material with a collimating optical element, wherein the collimating optical element couples the collimated second light signal to a second plane; placing a grating oriented in the second plane at a focal plane of the collimating optical element to produce a dispersed spectrum; collecting the dispersed spectrum by a second optical element; and passing light from the second optical element into the 2D array detector. 44. The method of claim 43 further comprising: encoding a spatial location of the second signal at the material along a first axis of spectral dispersion of the first light signal; and encoding a frequency of the second light signal along a second axis that is orthogonal to the first axis. 45. The method of claim 40, further comprising: taking differential images; and creating a 2D spectral surface in a single interaction of the first and second light signals. 46. The method of claim 45 further comprising revealing correlation dynamics by delaying the second light signal with respect to the first light signal, the time delay being controlled by a computer delay stage. 47. The method of claim 40, further comprising spectrally dispersing the first light signal with a grating. 48. The method of claim 40, further comprising generating at least one of the first light signal and a second light signal with a pulse duration in a range between 1 femtosecond and 10 picoseconds. 49. The method of claim 40, further comprising generating a first light signal in any one of far-infrared range, infrared range, near-infrared range, visible range, ultraviolet range, microwave range, or X-ray range. 50. An apparatus for spectroscopy comprising: a first light pulse source that generates a first light pulse; a first spectral dispersing element that spatially disperses the first light pulse in a first direction to form a spatially dispersed light incident on a material; a second light pulse source that generates a second light pulse incident on the material; a second spectral dispersing element that spatially disperses light from the material in a second direction different from the first direction; and a two dimensional detector that receives light from the material to detect a two dimensional spectral image. 51. The apparatus of claim 50, wherein the second dispersing element is a grating. 52. The apparatus of claim 50, wherein the second dispersing element is oriented with respect to a line of focus in a range of about 80 to 100 degrees of rotation. 53. The apparatus of claim 50, wherein the first light pulse comprises light pulses in a range between 1 femtosecond and 10 picoseconds in duration. 54. The apparatus of claim 50, wherein the first light pulse source is in an infrared range and the second light pulse is in a visible range. 55. An apparatus for 2D spectroscopy employing an altered infrared light pulse, comprising: a first light pulse source; a first frequency-dispersing element optically coupled to the first light pulse source; a material positioned to receive frequency dispersed light from the first frequency dispersing element such that light of different frequencies is spatially dispersed across the material; a second dispersing element that receives light from the material to form an image dispersed in two dimensions; a second light pulse source optically coupled to the material and the second dispersing element; and a two dimensional detector array that detects a spectroscopic image from the second dispersing element. 56. The apparatus of claim 55, wherein each of the first spectral dispersing element and the second spectral dispersing element is a grating, prism, curved grating, or other dispersive element. 57. The apparatus of claim 55, further comprising: the second light pulse after transmission through the material being received by a collimating optical element positioned at a distance f2 from the material; and the dispersed spectrum being received by a second optical element positioned in an optical path at a distance f3 from the oriented dispersing and at an optical distance f2 +f3 from the collimating optical element. 58. The apparatus of claim 55 further comprising an infrared laser source and a visible light source. 59. The apparatus of claim 55 further comprising a frequency conversion element that converts light from the second dispersing element.