Tuning of CW Lasers over Angstrom Bandwidths: Some Possible Approaches

摘要

This report is an investigation of several approaches to the problem of obtaining cw coherent optical signals whose wavelength can be scanned in a controlled fashion over a range of approximately 1 A or more. The methods discussed include the following internal tuning methods: Zeeman tuning; diffraction from acoustic waves; crystalstrain tuning; thermal tuning; tunable mode selection in wide lines; and Doppler-shift tuning using a beam of accelerated particles. The last method listed is believed to be a novel scheme for laser tuning. Frequency modulation using microwave frequencies and large modulation indices is also discussed as an external tuning method. Of all the approaches, it is probably the one that will provide the simplest and most effective solution. (Author)