Mirrorless fused silica based double-prism monochromator for continuous measurements from the near infrared to deep ultraviolet

Abstract

A mirrorless fused silica based double-prism monochromator was developed for continuous measurements over a wide spectral range. Lens positions were adjusted with respect to the spectral dependencies of the focal lengths. A guided optical rail has been implemented between both prisms. The monochromator enables measurements at photon energies between 0.4 and 7.3 eV. Straylight is suppressed by more than eight orders of magnitude, and simulated and measured spectral resolutions are compared. Suitable applications of the monochromator were demonstrated for material characterization by photoelectron emission, optical transmission, photocurrent, and surface photovoltage spectroscopy. The monochromator broadens the opportunities for the detection of defect states, especially by surface photovoltage spectroscopy in ultra-wide bandgap semiconductors.