Optical raytrace analysis as a method for evaluating grating-based spectrograph performance

Optical raytrace analysis of instrument performance offers a powerful tool for evaluating the optical design of instruments utilizing a spectrograph and multichannel array detectors. Methods for collecting light from a source, projecting the light to the sample, collecting the light from the sample, and projecting it to a spectrograph for analysis can be evaluated. The consequences of various design options on spectrograph performance can be used to optimize overall system performance by choosing the best solution for the application. Five optical systems using different methods for light collection from a sample and projection to a spectrograph are compared. The benefits and drawbacks with respect to spectrograph optical performance are compared for both one dimensional and two-dimensional array detectors. The five optical systems being compared utilize elliptical collection optics, a single lens, a lens pair, no collection optics, and an improved lens pair option.