UV Raman and fluorescence flame spectroscopy using a Sheridon grating spectrograph

A comparison is made of the near-diffraction order stray light performance between a mechanically ruled grating and a Sheridon holographically ruled and blazed grating when they are applied to UV laser combustion diagnostics. Due to the inherent groove smoothness in the holographic Sheridon grating, it is superior in stray light performance to the classically ruled grating. The limitation of the Sheridon grating to a maximum blaze wavelength of 250 nm does not hinder its application to UV Raman or fluorescence spectroscopy. Using a Sheridon grating in a spectrograph used for UV laser combustion diagnostics reduces or eliminates the need for Rayleigh/Mie scattering filtering and thus provides more sensitivity in detecting Raman or fluorescence signals lying close in wavelength to the laser line.