Design Considerations for a Portable Raman Probe Spectrometer for Field Forensics

Figure 1

The ray trace of a Raman line imaging spectrograph using an Offner convex grating and concentric mirror is shown in the figure on the left. The object plane and image plane are identical. The figure in the middle shows a notional Offner-Dyson layout where the collimating and focusing mirror are intentionally tilted to transfer the rays onto the convex grating so that the resulting image plane is below the input slit plane. A photograph of the Headwall/Andor demo system is shown on the right.