A versatile spectrometer by the use of a pressure-scanned Fabry-Pérot interferometer and a piezoelectrically-scanned Fabry-Pérot interferometer in tandem arrangement

A versatile spectrometer system which uses a pressure-scanned Fabry-Perot and a piezoelectrically-scanned Fabry-Perot in tandem arrangement is described. This system can be used either in synchronous scanning mode where two Fabry-Perots are scanned simultaneously or in band-pass filter mode where the pressure scanned Fabry-Perot is fixed at a frequency and only the piezoelectrically-scanned Fabry Perot is scanned. The former mode is used for the spectroscopy which needs high-resolution in relatively wide frequency region. The latter is suitable for very high-resolution spectroscopy such as precise measurements of Brillouin lines etc.