MLM is an ISO 9001:2008 certified company that provides metrology solutions to our customers with high quality and reliability.  Our inspection team tests 100% of all optics that we produce. We also provide test data with all prototype orders. High precision optical and mechanical metrology enable MLM to adhere to tight tolerances ensuring customer satisfaction. 

Interferometric Surface Figure Metrology

MLM utilizes laser interferometers to maintain accurate measurement of surface figure. These interferometers are used for both in-process and final product measurement of surface figure of flat and spherical surfaces with absolute accuracy of approximately R 0.001μm / △N 0.03fr. MLM also owns sub-aperture stitching interferometers to measure high numerical aperture, large clear aperture parts as well as complex shapes with nanometer-level accuracy. 

Our LUPHOScan 260 Non-contact 3D scanning interferometer enables measurements of aspheric as well as mild freeform surfaces with a measurement range up to 260 mm diameter. Measurements are also supported by our QED SSI Non-contact Sub-aperture stitching Interferometer providing measurement of optics up to 300 mm diameter depending on surface prescription. In addition, MLM possesses various Zygo GPI XP/Verifire interferometers with horizontal and vertical configurations for surface measurement of plano and spherical surfaces and measurement of Transmitted wavefront errors, PSI and QPSI analysis using Metropro/Mx software. 

MLM can also support UV interferometry with more details available upon request.

Spectrophotometric Coating Curve Metrology

MLM owns UV-Vis-NIR spectrophotometers and FTIR spectrophotometers, covering a wavelength range from 175nm to 25000nm and photometric range of OD8. Distinguishability of 0.1nm allows us to characterize reflectivity, transmission, polarization extinction, retardance, and other functional characteristics across all angles of incidence.

Aspheric Lens Contour Metrology

MLM utilizes a Taylor-Hobson PGI contact contourgraph to measure peak to valley error of spherical, diffractive, and aspheric surfaces including large-departure aspheric surfaces. The contourgraph measures within 0.1μm level accuracy and the measurement angle can reach 90 degrees. MLM also also uses non-contact 3D interferometric scanners such as the Zygo ZeGage for testing aspheric lenses. The accuracy of these scanners reaches 0.05μm and supports tested element dimensions of up to 260mm (diameter) by 75mm (height).  

The above metrology can be combined with our QED MRF technology (Magneto Rheological Finishing) and IBF Technology (Ion Beam Figuring) for post-polishing correction to achieve ultra-high surface accuracy.

Additional Measurement Equipment

MLM possesses a large collection of additional equipment for various types of required metrology:

· Trioptics lens centration systems enabling measurement of centration errors on lens components and multi-element lens assemblies as well as measurement of EFL, BFL, Radius and on-axis MTF

· OGP smart scope and Optical CMM microscope allowing measurement of mechanical dimensions and inspection of surface defects

· Goniometer and Autocollimator devices for measuring optical parallel, angular measurements on prisms

· Coordinate measurement machines (e. g. MH3D DCC CMM) enabling verification of mechanical dimensions

· Image Science MTF tester providing on-axis, and off-axis MTF measurement on visible and IR optical assemblies

· Optical comparator

Environmental Testing Capability

MLM's environmental chambers can meet our customer's most stringent and diverse environment test requirements. Our capabilities include, but are not limited to, the following:

· Laser Damage Threshold Testing

· Coating adhesion, abrasion, humidity resistance, and robustness through thermal cycling to typical ISO and MIL PRF specifications

· Salt fog testing

· Shock / Vibration testing