Toptica Photonics AG is offering its FPI 100 Fabry-Perot interferometer line with 4-GHz free spectral range from 380 to 1700 nm. The instruments achieve a finesse of up to 1000 via broadband HR-coated mirrors. Five mirror sets cover the full spectral range, and the modular design allows the user to change the wavelength as well as the free spectral range. Low-noise detectors, high-speed amplifiers, a single-mode fiber coupler and thermal control tools are available. The devices can be driven with either the series DL scanning electronics or an independent scan generator.