A Wavelength Calibrator for the 0.6–1.4 μm Band Based on Fluorescent-lamp Starters

Abstract

A calibrating apparatus for spectrometers of the red and near infrared bands based on the analysis of the emission spectra of inert gases is described. One feature of this calibrator is the use of readily available starters for fluorescent lamps as optical emitters. A radio-frequency discharge was used to excite gases in the starters. Starter models (with neon and argon) were selected that made it possible to cover the important spectral band for diode lasers (600–1400 nm) with reference lines. The use of a calibrator as an auxiliary gas-discharge cell for diode-laser absorption spectrometry of low-temperature plasma was demonstrated. When a high-frequency discharge was excited in the starter by an outer ring electrode, a signal of 30% absorption at the 1s₅ → 2p₉ transition of metastable Ar* atoms was recorded with a low noise level. This result is evidence of the possibility of using the calibrator as an optical reference for simple systems of laser-frequency stabilization or for investigating the shifts of spectroscopic lines of Ar or Ne atoms.