Optical Spectrometers Optical Spectrometers Introduction A spectrometer is an optical system that transmits a specific band of electromagnetic spectrum . Typical applications are isolation of a narrow band of radiation from a continuum light source for absorption measurements, or analysis of the emission from excited atoms or molecules. Monochromator designs A typical monochromator design is shown below. Schematic of a Czerny-Turner monochromator Scanning is accomplished by rotating the grating. The wavelength range that the monochromator transmits.
Dispersion depends on the focal length, grating resolving power, and the grating order.
The minimum bandpass of the spectrometer, usually determined by the aberrations of the optical system. The wavelength of maximum intensity in first order. Spectrograph A spectrometer that records a wide bandpass with a photographic plate or an array detector. The spectrometer requires a flat image field. Polychromator A spectrometer with multiple detectors for simultaneous detection of multiple analytes.