Abstract: A Raman analyzer for analyzing light emitted from a Raman cell is provided that has a beam splitter configured to split the light emitted from the Raman cell into a first beam and a second beam. An atomic vapor filter can be used to filter a Raman scattered line from the first beam and a chopper system can periodically interrupt the first and second beams that are directed towards a photo detector, which can convert light from the first and second beams into an electrical signal. The signal output from the photo detector can optionally be amplified, digitized, Fourier filtered, and/or subjected to Fourier analysis.

Abstract: A Raman analyzer for analyzing light emitted from a Raman cell is provided that has a beam splitter configured to split the light emitted from the Raman cell into a first beam and a second beam. An atomic vapor filter can be used to filter a Raman scattered line from the first beam and a chopper system can periodically interrupt the first and second beams that are directed towards a photo detector, which can convert light from the first and second beams into an electrical signal. The signal output from the photo detector can optionally be amplified, digitized, Fourier filtered, and/or subjected to Fourier analysis.

Abstract: A compact, ultra-sensitive, inexpensive NIR spontaneous Raman spectrometer is presented. High sensitivity is achieved by the use of a multi-pass cell configuration combined with the electromotive properties of silicon crystal surface. A thin layer of silicon oxide chemisorbs molecules, which stick to its surface without altering their spectroscopic signatures. This new Raman spectrometer may be used to detect less than 40 ng (?0.5 n mol) of ammonium nitrate deposited on the silicon surface with the signal-to-noise ratio better than 50 during 0.1 s recording time and for an illuminated area of 2×10?8 m2. These results may be useful in many areas, for example the foundation of an extended project to record the dissolved NO3? ions in a large river such as the Mississippi.

Abstract: A compact, ultra-sensitive, inexpensive NIR spontaneous Raman spectrometer is presented. High sensitivity is achieved by the use of a multi-pass cell configuration combined with the electromotive properties of silicon crystal surface. A thin layer of silicon oxide chemisorbs molecules, which stick to its surface without altering their spectroscopic signatures. This new Raman spectrometer may be used to detect less than 40 ng (?0.5 n mol) of ammonium nitrate deposited on the silicon surface with the signal-to-noise ratio better than 50 during 0.1 s recording time and for an illuminated area of 2x10?8 m2. These results may be useful in many areas, for example the foundation of an extended project to record the dissolved NO3? ions in a large river such as the Mississippi.

Abstract: A Raman analyzer for analyzing light emitted from a Raman cell is provided that has a beam splitter configured to split the light emitted from the Raman cell into a first beam and a second beam. An atomic vapor filter can be used to filter a Raman scattered line from the first beam and a chopper system can periodically interrupt the first and second beams that are directed towards a photo detector, which can convert light from the first and second beams into an electrical signal. The signal output from the photo detector can optionally be amplified, digitized, Fourier filtered, and/or subjected to Fourier analysis.