Recently much attention is being paid to the near-infrared spectroscopy of various substances, including gases, liquids, and solids, along with its potential applications1–3 to optical communications. In fact, a great deal of spectroscopic information on gases may be involved, because a number of overtones and combination bands of IR active vibrations have been located. This information should also be essential for the frequency stabilization or locking of a semiconductor laser in reference to the narrow absorption line of a specific gas in this region for future coherent optical communications. Although there are several coherent light sources useful for near-IR spectroscopy, they are mostly discrete or narrowband tunable, and a widely tunable coherent system has not yet been fully utilized. In this paper, we describe the application of a continuously tunable system to the absorption spectroscopy of various gases for the first time using a dye-laser-pumped hydrogen Raman cell, which covers nearly a 0.7–3-μm region incorporating a microprocessor controlled operation and data processing.
© 1984 Optical Society of AmericaPDF Article