High speed spectroscopy using temporal positioned optical fibers with an optical scanner mirror
Systems and methods for examining spectral data over the course of a high speed event are described. The systems and methods can enable observation of the spectral evolution of a transient phenomenon into segment intervals on the order of, milliseconds or microseconds. The methods include reflecting light from an event off of a rotating mirror and sequentially delivering light from the mirror to a series of optical waveguides for sequential spectral analysis. The systems and methods can be useful in a wide variety of applications such as, LIBS applications; examination of high energy devices such as explosions or simulations of explosions; examination of deposition processes, e.g., coating formations; examination of chemical reactions; etc.
1. A spectroscopy system comprising:
a rotatable mirror comprising a surface that is configured for location in optical communication with an event;
a collector in optical communication with the rotatable mirror, the collector comprising a facing surface and a terminal portion, the collector being located such that light from an event is reflected off of the rotatable mirror and thence directly to the facing surface of the collector, the collector comprising a plurality of optical waveguides, each of the optical waveguides comprising a first end and a second end, each of the optical waveguides comprising a collection lens at the first end, the collection lenses being located in series across the facing surface of the collector, the terminal portion of the collector comprising the second end of each of the optical waveguides, the second ends being located in series across the terminal portion; and
a spectrophotometer comprising at least one detector, the spectrophotometer being in optical communication with the terminal portion of the collector such that light that exits each of the optical waveguides via the second end of the optical waveguides is communicated to the spectrophotometer.
2. The spectroscopy system of claim 1 , wherein the rotatable mirror comprises a plurality of reflective faces.
3. The spectroscopy system of claim 1 , further comprising a waveguide system in optical communication with the rotatable system and configured to carry light from the event to the rotatable mirror.
4. The spectroscopy system of claim 1 , the optical waveguides comprising optical fibers.
5. The spectroscopy system of claim 4 , wherein the optical fibers comprise multi-mode optical fibers.
6. The spectroscopy system of claim 1 , the spectrophotometer comprising multiple detectors.
7. The spectroscopy system of claim 1 , wherein the detector comprises a two dimensional array of sensing elements.
8. The spectroscopy system of claim 1 , the facing surface defining a curve.
9. A method for examining a high speed event comprising:
locating a rotatable mirror in optical communication with the high speed event such that for a first time segment light from the event is reflected off of the rotatable mirror and thence directed from the mirror directly to a facing surface of a collector, the collector comprising a plurality of optical waveguides, each of the optical waveguides comprising a first end and a second end, each of the optical waveguides comprising a collection lens at the first end, the collection lenses being located in series across the facing surface of the collector, a terminal portion of the collector comprising the second end of each of the optical waveguides, the second ends being located in series across the terminal portion, the light of the first time segment being directed from the mirror to a collecting lens of a first optical waveguide that is one of the plurality of optical waveguides of the collector, the first optical waveguide collecting the light of the first time segment as a first spectral signal;
rotating the mirror such that for a second time segment following the first time segment light from the event is reflected off of the rotatable mirror and thence directed from the mirror directly to a collecting lens of a second optical waveguide that is one of the plurality of the optical waveguides of the collector, the second optical waveguide collecting the light of the second time segment as a second spectral signal;
the first spectral signal traveling along the first optical waveguide, exiting the second end of the first optical waveguide, and thereafter being detected by a detector of a spectrophotometer;
the second spectral signal traveling along the second optical waveguide, exiting the second end of the second optical waveguide, and thereafter being detected by the detector of the spectrophotometer; and
the spectrophotometer thereafter carrying out a spectral analysis for each of the first and second spectral signals.
10. The method of claim 9 , wherein the high speed event takes place over a period of time of about 1 second or less.
11. The method of claim 9 , wherein the event comprises formation of a plasma.
12. The method of claim 11 , wherein the plasma is a laser-induced plasma.
13. The method of claim 9 , the spectral analysis comprising distributing the first spectral signal across a first array of sensing elements of the spectrophotometer.
14. The method of claim 13 , the spectral analysis further comprising distributing the second spectral signal across a second array of sensing elements of the spectrophotometer.
15. The method of claim 14 , wherein the first array of sensing elements comprises a two dimensional array of sensing elements.
16. The method of claim 13 , further comprising rotating the mirror such that for one or more additional time segments sequentially following the second time segment, light from the event is reflected off of the rotatable mirror and thence directed from the mirror sequentially to one or more additional collecting lens of one or more additional optical waveguides of the collector, the one or more additional optical waveguides sequentially collecting the light from each of the one or more additional time segments as one or more additional spectral signals.