Interferometers for Optical Metrology

Interferometers for Non-Contact Inspection

Interferometers are optical instruments that measure distance, surface topography, refractive index, or wavefront quality by analyzing the interference of coherent light beams. In non-contact inspection and optical metrology, interferometers enable sub-wavelength resolution measurements of optical components, precision mechanics, and semiconductor structures.

On FindLight, interferometers in the light detection domain typically employ laser or broadband illumination with camera-based detection of interference fringes. Configurations may include Fizeau interferometers for surface flatness, Michelson and Mach–Zehnder interferometers for path length and refractive index measurements, and Twyman–Green interferometers for system wavefront characterization.

Typical Specifications and Use Cases

Key specifications for interferometers listed in this category include:

• Wavelength: common laser lines (e.g., 532 nm, 632.8 nm, 1064 nm) or broadband sources for white-light interferometers.
• Measurement range: from sub-micrometer path differences up to several millimeters of vertical scan for surface profiling.
• Resolution and repeatability: down to a fraction of the operating wavelength for phase-shifting interferometers.
• Aperture size: clear aperture suitable for small optics up to large-diameter windows and mirrors.
• Data acquisition: CCD/CMOS detector type, frame rate, and supported data interfaces.
• Environmental stability: vibration tolerance, thermal drift, and air-path sensitivity.

Interferometers are used for optical component QA, coating uniformity checks, precision stage calibration, adaptive optics feedback, and material characterization via refractive index or thickness measurements.

Buyer Guidance on FindLight

When evaluating interferometers on FindLight, compare the operating wavelength with your sample materials and coatings, confirming compatibility with surface reflectivity and transmission. Check aperture size and mechanical configuration to ensure your parts and fixtures can be accommodated without vignetting.

Assess resolution, repeatability, and dynamic range against your tolerances, especially for high-flatness optics or high-NA wavefront measurements. Review detector type and available software interfaces to verify integration with existing DAQ and control systems.

For each interferometer, you can contact suppliers directly, request detailed quotations, and clarify customization options such as alternative wavelengths or environmental enclosures. No registration is required to send RFQs, allowing rapid comparison of interferometers across multiple vendors on FindLight.