Optical testing - Gestione Silo

Testing

A metrological laboratory equipped with efficient and cutting-edge tools to guarantee quality optical components.

Rigorous methodology, experience and sensitivity of the operators to inspect and qualify precision optics.

In our factory, we have the ability to perform all the optical tests required by the reference standards. Our operators are trained to perform the necessary measurements and checks in an optical laboratory. All the instruments of the test room (gauges, micrometer comparators, precision scales, primary in general) are kept under constant metrological control. Optics awaiting testing are stored in a nitrogen chamber under controlled environmental conditions.

Upon reservation, we provide metrological laboratory and optical testing services on customer components and produce custom measurement set-ups on optical bench.

Cosmetic tests

Basic control parameters for laser optics or near focal plane, the control of the cosmetics is applied on all our components and consists in giving an evaluation of the defects present on an optical surface in terms of scratches, dots, halos, etc.

We have optic machines that aid our operators in this task with the possibility of enlargements from 4x to 6x.

For smaller defects, we have a Nikon microscope with objectives up to 100 magnifications.

Centering tests

The department is equipped with 3 laser centerers with which to measure the centering both in crossing and in reflection of flat and radius optics. Each centering device is equipped with specific equipment to position lenses with different geometries.

Interferometric tests

The testing room is equipped with a latest-generation Zygo interferometer, which allows measurements of surface quality up to λ / 20 to be performed.

A wide range of reference planes and spheres allow us to perform measurements both on planes and on radii up to λ / 20, both in terms of reflection and of wavefront deviation.

For controls in line with production and in high vibration environments, we have two AV100 interferometers, one of which is mounted on a vertical slide.

Roughness measurements

We have a controlled roughness tester, with which to check the texture of the surfaces, both for smooth and rough surfaces.

The Zygo NewView optical roughness tester is also in use in our laboratory. It guarantees high performance during the final product testing phase and supports the improvement and stability of production processes with precious information with a high degree of precision. The measurements are, in fact, guaranteed with a vertical resolution higher than 0.1nm, a lateral resolution from 0.45 to 11.8μm, an accuracy of the step Height and a repeatability of less than 0.1nm RMS.

We can support specific requests to characterize machining with particular roughness requirements.

Process Controls

During the optical construction process, numerous checks are performed with periodically calibrated precision instruments, horizontal and vertical interferometers (Zygo, Moeller Wedel), microscopes as well as a wide range of control forms (about 2000).

Spectrophotometric measurements

We have a Perkin Elmer Lambda 950 spectrophotometer available, with which we can verify the transmission and reflection characteristics of our coating optics from 300 to 3000 nm.

For coatings working at longer wavelengths, we collaborate with measurement laboratories in the area.

Measurement of profiles

The measurement of profiles is performed through a Mitutoyo profilometer with zoom up to 147 magnifications: the operators are trained in the use of the control software dedicated to the use and execution of this type of measurement.

Radius measurement

The radius measurements are carried out with interferometric reference systems coupled to calibrated slides equipped with an encoder. These controls take place on the production line with an Optotech vertical slide for measurements up to 1m radius. The final test, with a Zygo slid-interferometer system for measurements up to 1.5m or with a calibrated radiometer, is the verification of bending radii up to 2 m.

Roundness measurement

The ROTO R160 METRIC roundness tester allows checking the roundness of reference spheres and cylinders. For optimal use of the instrument, our operators have followed a course on circular geometries and their measurement. We have developed roundness samples used as reference in metrology laboratories.

Angle and pyramid measurement

Thanks to an optical spectrogoniometer and several collimators, we can characterize angles and pyramids of wedges and prisms with precision up to the second of arc.

Thickness measurements

To measure the thickness of the optics, we use an Xonox measuring station that allows us to characterize the optics with a total uncertainty to the order of 0.002 mm.

Other measures

We are also equipped to perform other types of measurements for special requirement,s such as corner measurements and seal tests, as well as collaborating with specialized laboratories on measurements of particular requirements.