Applications
- Analytical Chemistry
- Surface Chemistry and Material Science
- Characterization of variety of samples including liquids, films, and powders
Raman Microspectrometer is a compact, easy to assemble and cost effective solution for your Raman Spectroscopy needs. Figure 1 shows the homebuilt Raman Microspectrometer system used in Newport’s Technology & Application Center (TAC). The setup is based on a 532 nm CW single frequency DPSS laser (see Excelsior CW Lasers, Spectra-Physics) as the light source. Lasers with longer wavelengths are more preferable in Raman experiments since some of the fluorescence signals can be avoided.
Figure 1. (a) A diagram shows the principle of the experimental setup. M: mirror, W: waveplate, P: polarizer, S: sample, F1: 45˚ beamsplitter, F2: long wave pass filter, L1: objective or lens, L2: condenser lens, ES: entrance slit of the spectrometer. The dashed circle marks the attenuator. (b) Photograph of the Raman Microspectrometer setup in the Newport TAC. The laser is shown in green, while the Raman scattered field is shown in orange.
Using the above set up, we have performed experiments on several samples. In all of the experiments, the exposure time was less than 20 seconds. In some cases, like with cyclohexane, the measurement can actually be monitored in real time (the frame was updated every second and the result is satisfactory as shown in the figure below).
Figure 2. Raman spectra of n-hexane (a), methanol (b), acetone (c), water (d), carbon tetrachloride (e), cyclohexane (f). The inset of each spectrum shows the region where the peaks are most congested.
Figure 3. The chemical structures of ethyl acrylate and ethyl propionate (a). The Raman spectra of ethyl acrylate and ethyl propionate in CCl4 (b). Blue/red traces are for ethyl acrylate/propionate solution, respectively. The spectra in the 1600 cm-1 region are shown in the inset where the dominant displacements of the normal modes are also demonstrated.
For detail please read Application Note 42 .
