DEVICE AND METHOD FOR SPECTROSCOPICALLY DETECTING MOLECULES

• US 20120210796A1
• Filed: 08/24/2010
• Published: 08/23/2012
• Est. Priority Date: 08/28/2009
• Status: Abandoned Application

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Schade, Wolfgang
• Application Number:
  US13/392,702
• Publication Number:
  US 20120210796A1
• Time in Patent Office: Days
• US Class Current: 73/655
• CPC Class Codes: G01N 2021/1704 in gases
• CPC Class Codes: G01N 2021/1708 with piezotransducers
• CPC Class Codes: G01N 21/1702 with opto-acoustic detection, e.g. for gases or analysing solids
• CPC Class Codes: G01N 2201/0697 Pulsed lasers
• CPC Class Codes: G01N 29/2425 optoacoustic fluid cells therefor

Abstract

A method and a device for spectroscopic detection of molecules, containing a resonance body, an apparatus for identifying a vibration of the resonance body and at least one laser light source, the laser light of which interacts with the molecules to be detected and which is designed to emit light pulses with a duration of less than 200 fs, the device also containing apparatus for pulse shaping the light pulses emitted by the laser light source by modulating the amplitude and/or the phase, to generate sequentially different pulse shapes of the light pulses.

Claims

1-20. -20. (canceled)

21. Device for spectroscopic detection of molecules, said device comprising

a resonance body,

an apparatus for identifying a vibration of the resonance body and

at least one laser light source being adapted to produce a laser light being shaped to pulses with a duration of less than 200 fs, said laser light being intended to interact with the molecules to be detected

an apparatus for pulse shaping of the laser light pulses by modulating the amplitude and/or the phase, and said apparatus for pulse shaping being adapted to sequentially generate different pulse shapes.

22. Device according to claim 21, comprising further a control apparatus being adapted to correct a deviation of the actual shape of the light pulses from a predeterminable shape.

23. Device according to claim 21, comprising further an optical modulator.

24. Device according to claim 23, wherein the optical modulator and the resonance body have an identical resonant frequency.

25. Device according to claim 23, wherein the optical modulator and/or the resonance body are made of a piezoelectric material.

26. Device according to claim 21, wherein the resonance body comprises at least two elongated prongs having a first end and an opposing second end, wherein the elongated prongs are arranged approximately in parallel to each other and are respectively fixed with their first ends to a connection element, wherein the second ends project freely.

27. Device according to claim 21, wherein a volume being intended to hold the molecules to be detected is at least partly delimited by the resonance body.

28. Device according to claim 26, wherein a volume being intended to hold gas molecules to be detected is at least partly delimited between the at least two elongated prongs.

29. Device according to claim 21, comprising further an optical system being adapted to focus on the resonance body the light emerging from the interaction between the laser light and the molecules to be detected.

30. Device for spectroscopic detection of molecules, said device comprising

a resonance body,

an apparatus for identifying a vibration of the resonance body and

at least one laser light source being adapted to produce a laser light being shaped to pulses with a duration of less than 200 fs, said laser light being intended to interact with the molecules to be detected

an apparatus for pulse shaping of the laser light pulses by modulating the amplitude and/or the phase, and said apparatus for pulse shaping being adapted to sequentially generate different pulse shapes

an optical modulator being adapted to blank the light pulses with a frequency corresponding to the resonance frequency of the resonance body.

31. Device according to claim 30, wherein the resonance body and/or the optical modulator comprises at least two elongated prongs having a first end and an opposing second end, wherein the elongated prongs are arranged approximately in parallel to each other and are respectively fixed with their first ends to a connection element, wherein the second ends project freely.

32. Device according to claim 30, wherein a volume being intended to hold the molecules to be detected is at least partly delimited by the resonance body.

33. Device according to claim 30, comprising further a control apparatus being adapted to correct a deviation of the actual shape of the light pulses from a predeterminable shape

34. A method for spectroscopic detection of molecules, said method comprising the following steps:

Generating light pulses with a duration of less than 200 fs and a predeterminable pulse shape,

Allowing the light pulses to interact with the molecules to be detected,

Allowing the molecules to be detected to interact with the resonance body, thereby causing a vibration of the resonance body,

Detecting the vibration of the resonance body, and

Repeating the aforementioned steps sequentially, thereby generating different pulse shapes of the light pulses.

35. Method according to claim 34, wherein the predeterminable pulse shape of the light pulses with a duration of less than 200 fs is generated by modulating the amplitude and/or the phase.

36. Method according to claim 34, wherein the actual shape of the light pulses is adjusted to an intended shape by means of a control device.

37. Method according to claim 34, wherein the light pulses are blanked with a frequency corresponding to the resonance frequency of the resonance body.

38. Method according to claim 34, wherein the resonance body at least partly delimits a volume being intended to hold the molecules to be detected and wherein the molecules to be detected are introduced into this volume in gaseous form.

39. Method according to claim 34, wherein light emerging from the interaction between the laser light and the molecules to be detected is focused on the resonance body.

40. Method according to claim 39, wherein the molecules to be detected are concealed behind a wrapping and

in a first method step an opening is formed into the wrapping by means of a first multiplicity of light pulses with a duration of less than 200 fs and a first pulse shape, and

in a second method step at least one second multiplicity of light pulses with a predeterminable second pulse shape interacts with the molecules to be detected, for the spectroscopic detection of said molecules.

41. Method according to claim 34, wherein the vibration of the resonance body is detected by means of a lock-in amplifier.

42. Method according to claim 34, wherein a blasting agent and/or explosive material is detected.