Members of the Academic Staff

The Optical Metrology Group (OMG) was recently restructured being part of the “Optics, Microwaves and Acoustics Department” (DOMA by its Spanish acronym), at the Institute for Applied Sciences and Technology (ICAT by its Spanish acronym). In the early 1990s, Prof. Rufino Díaz-Uribe founded the first research group mainly dedicated to the field of Optical Testing. The group was exclusively considering non-destructive tests methods based on physical and geometrical optics; i. e., they were working with both geometrical and interferometrical test methods. Since the beginning of its foundation, many researchers have been incorporated at ICAT-UNAM. It is important to comment that a constant of the DOMA has been the continuous equipment of all laboratories supporting the researcher activities, in particular, the OMG-ICAT works to develop new methods and configurations in the field of optical non-destructive tests.

The OMG-ICAT continuously improves technical solutions to provide either qualitative or quantitative evaluations for optical surfaces, assuming a basic knowledge about the geometrical and physical properties of the optical surfaces under test, in order to implement an exact ray tracing through it, and finally by using numerical integrations we are able to retrieve the shape of the surface under test. It is important to state that we have properly tested several reflective and refractive optical surfaces either with or without symmetries around the optical axis, in a wide range of sizes, shapes, by using the traditional optical tests which extends from retrieve classic profile and measurement of the quality of surfaces with standard methods such as null tests and laser deflectometry, to highly advanced coordinate measurement by using interferometrical tests. The group’s goal is to attain a high precision to retrieve the shape of the optical surfaces under test based on the null tests, which as is well known are motivated by the fact that the interpretation of the surface shape under test is simplified, and the visual analysis turns out to be straightforward for both qualitative and quantitative tests.

Alternatively, as is well known, the aspheric refracting and reflecting surfaces are widely used in both imaging and non-imaging optical systems, because this kind of surfaces eliminates many aberrations such as spherical, astigmatism, coma and also they can reduce the distortion in wide-angle lenses. It is important to remark that these surfaces can be used for non-imaging optical systems; for instance, in solar concentrators and illumination systems such as collimators and condensers of light. Furthermore, for imaging optical systems, these surfaces can yield sharper images more efficiently than spherical surfaces do. The OMG-ICAT has properly provided analytical formulae to design aspheric lenses, which principally reduces the spherical aberration, and we have also adequately implemented null tests to evaluate the shape of singlet lenses, concave/convex conic mirrors with symmetry of revolution around the optical axis, additionally large plane mirrors and CPC mirrors with potential applications in the field of solar concentrators. Lately we have tested the shape of human corneas in vivo and in situ, considering the profile of corneas being an aspheric surface. 

Recently, a major breakthrough in the field of optical design has been the implementation of the commonly called freeform surfaces (FFS), which are widely studied in both imaging and non-imaging optical systems, because this kind of optical surfaces can properly reduce many aberrations more efficiently than aspheric surfaces do. For instance, FFS can be implemented in many fields for optical systems; the number of applications can be extended from intraocular human cornea, progressive lenses (these are current research topics at the National Laboratory for Optics of Vision; LANOV in Spanish) regarding refractive FFS to solar energy technologies, such as automobile headlamps, illumination systems, concentrators of light regarding reflective FFS. They can be fabricated by using computer numerical controlled milling equipment (CNC) or 3D printers. It should be noted that the FFS have not rotational symmetry, limiting the implementation of standard methods of evaluations to test this kind of optical surfaces. Actually, the researchers associated to the OMG-DOMA-ICAT, are working in the field of optical design, fabrication and optical testing for this kind of exotic surfaces, which are a big challenge around the worldwide.

  • Metrology and optical testing.


    Optical instrumentation.

  • Optical Design for solar concentrators.

  • National Laboratory for Optics of Vision.

  • Freeform surfaces evaluation.

  • Optical Design for Non-Conventional Optical Surfaces.

  • Testing of reflective parabolic trough solar collectors.

  • Optical Design and Quantitative evaluation for Reflective and Refractive Fresnel Lenses.