ZYGO's horizontal-axis Large Aperture Systems offer the unique capability to maintain two independent metrology cavities; one of the nominal interferometer aperture (4") and the other a choice of one of four beam expander diameters (12", 18" 24" and 32"). When configured with the proper accessories the Large Aperture Systems can be used to measure both surface form and transmitted wavefront quality.Large Aperture Systems consist of... The interferometer mainframe (Verifire™ or Dynafiz®) MUX cube (switchable mirror assembly) Beam Expander (available as 12", 18", 24" or 32" diameter) Phase measuring receptacle (for 12" and 18" systems; 24" and 32" utilize wavelength shifting mainframes and do not require a PMR) Reference optics - transmission and reference flats as required depending on the optical configuration Mounts - Mounts for the reference optics and test optics are availableVerifire XLThe Verifire™ XL interferometer system is a stand-alone large aperture workstation for measuring flat surfaces up to 12 inches (300 mm) in diameter. Examples include front-surface reflectors, windows, and semiconductor wafers or wafer chucks.The system is a downward-looking configuration, which eliminates the need for special part holding fixtures in most situations. The operator simply places a test part on the flat surface of the tip/tilt stage, and slides the entire stage under the measurement aperture.With its small footprint, the Verifire XL system requires a minimum of valuable floor space in your production facility. Everything you need is built-in, including the vibration isolation system. The transmission flat is also built-in and pre-aligned, requiring no adjustment, which simplifies operation and increases throughput.Also included is ZYGO's exclusive QPSI™ acquisition technology which eliminates fringe "print through", enabling reliable high-precision measurements in the presence of vibration often found in production environments.