High Resolution Multi-grating Spectrometer Controlled by an Arduino

The designs for a high resolution Czerny-Turner spectrometer are presented. The results of optical simulations using ZEMAX are shown, and the design of a triple turret using two servo motors and an Arduino based control system is reported. Results from optical simulations show that one of the most important factors affecting spectral resolution is the focal length of mirrors. Increasing the focal length allows for a greater degree of spatial dispersion of light diffracted from the gratings and also reduces optical aberrations. Radiation of wavelengths around 1550 nm are shown to have very noticeable aberrations in certain designs, evident by a large degree of smudging. Using parabolic mirrors instead of spherical mirrors is demonstrated to have a negligible effect when compared with increasing focal length. The optical simulations and preliminary testing of mechanical components show that it is possible to build a cost effective high resolution Czerny-Turner spectrometer using off the shelf components.