Frequency modulation spectroscopy comparison

Silver, J.A. Frequency-modulation spectroscopy for trace species detection theory and comparison among experimental methods. Appl. Opt. 1992, 31 (6), IQl-lYl. 

F.S. Pavone, M. Inguscio, Frequency- and wavelength-modulation spectroscopy Comparison of experimental methods, using an AlGaAs diode laser. Appl. Phys. B 56, 118 (1993)... 

Remarks Steimle et al. [OOSte] have applied transient frequency modulation absorption spectroscopy to PtC and TiS molecules as produced in a laser ablation supersonic expansion source, and discussed the results in comparison with LIF detection techniques. 

This paper reports a sensitive optical interferometric technique dual frequency modulation (DFM) for measuring and stabilizing a laser frequency by comparison, in a single step, to a radio frequency (rf) standard. Conversely, a low-noise rf source can be stabilized by a laser frequency reference. A prototype has demonstrated a resolution of 2 parts in 10 , but devices currently under development should have a resolution of 10 and an absolute accuracy of 10" . The method may be competitive with the optical frequency synthesis chain in accuracy and its simplicity suggests its convenient use in metrology, high-precision optical spectroscopy, and gravity wave detection. 

The main part of the book presents various applications of lasers in spectroscopy and discusses the different methods that have been developed recently. Chapter 6 starts with Doppler-limited laser absorption spectroscopy with its various high-sensitivity detection techniques such as frequency modulation and intracavity spectroscopy, cavity ring-down techniques, excitation-fluorescence detection, ionization and optogalvanic spectroscopy, optoacoustic and optothermal spectroscopy, or laser-induced fluorescence. A comparison between the different techniques helps to critically judge their merits and limitations. 

---