Exfo Electro-Optical Engineering Inc. has announced the reintroduction of the Burleigh RC-110 Fabry-Perot interferometer for high-resolution spectroscopy. The RC-110's plano mirror cavity design results in continuously variable cavity spacing and a free spectral range of from 1 to more than 1500 GHz. Interchangeable mirror sets enable operation at wavelengths of 450 nm to 12 µm. Super Invar construction offers thermal stability, and mirror scanning and alignment control are performed piezoelectrically. The instrument features a 50-mm clear aperture for applications with low signal strengths that require a large, solid angle of viewing.