Metrology tests
Metrology laboratory
Optical elements are widely used in various fields of application – from single element in simple optical system to very complex industrial systems, where every parameter of each element is critical to overall system reliability and performance. Altechna is concerned about your success in experiments and final product performance, therefore in cooperation with Vilnius University we are performing following test procedures:
• Optical surface quality measurements;
• Transmittance and reflectance measurement in 190-1100 nm range;
• Surface flatness, wavefront distortion measurements of flat and spherical optics;
• Angle measurements for prisms, wedges and other optics;
• Non-contact ROC, Focal length measurements;
• Custom made tests.
Also we offer:
• Laser Induced Damage Threshold (LIDT) tests for wide range of laser wavelengths;
• Optical absorption tests according to ISO 11551 standard;
• Total scattering measurements;
• Transmittance measurements from 190 nm to 20000 nm.
For measurements we apply:
• Stereo and analytical microscopes;
• Spectrophotometer;
• Interferometer;
• Goniometer;
• Spherometer;
• DPSS CW lasers (405, 532, 632,8, 1064)
• Femtosecond laser Pharos with harmonic module Hiro (Light Conversion).
Equipment
Equipments we use for quality measurements:
| Interferometer | Goniometer | Lens testing |
| For accurate metrology of surface form for flat and spherical surfaces we are using ZYGO Verifire XP/D Phase Shifting interferometer. Variety of accessories allows to our engineers to measure coated and uncoated optics, radius metrology allows us to test spherical surfaces for form irregualities and Radius of Curvature with radius of ±20 - ±1000 mm. For polarization sensitive optics, such as laser crystals, linear polarization option is used. | High accuracy goniometer with air bearing rotary table allows to measure angles for prisms, polygons, wedges and plano optics with accuracy better than 0.6 acrsec. Developed software kit allows to determine refraction indices to identify glass types. | Non-contact and less damaging method is used for lens radius of curvature, focal length and centration measurements. Air bearing stage and electronic collimator allows to reach less than 0.1 μm accuracy when measuring centering errors. Additional accessories extend our capabilities to measure ROC and focal length values up to ±5 meters, while standard devices covers only ±450 cm. |
Measurement setups
Setup for polarization sensitive elements transmission test. For other than 532 nm, 632 nm, 1030 nm and 1064 nm wavelengths spectrophotometer is used.
Setup for AR coated windows, lenses, mirrors, waveplates or other surfaces reflection test. Test angle can vary from close to zero degrees. Reflectance also can be measured in spectrophotometer with reflectance module at fixed 5 degrees angle.
Setup for waveplate (λ/2, λ/4) test. For other than 532 nm, 632 nm, 1030 nm and 1064 nm wavelengths spectrophotometer.
Setup for axicon quality test. Screen is used for visual ring inspection, CCD – for Bessel beam profiling.
Measurement setup for distortion of a plane wave transmitted through windows, filters, and prisms.
Measurement setup for surface flatness of plano elements such as mirrors, prisms, and windows. This setup also is used for parallelism measurement of transparent materials.
If transmission sphere is used instead transmission flat, convex or concave spherical surfaces canbe examined for surface figure and irregularity.
Goniometer is used for wedged windows, prismsangle, pyramidal error measurements.
Non-contact method is used for Radius of Curvature for convex and concave lens measurements. Cylindrical lens is also tested with this setup.
Non-contact method is used for Effective Focal Lenght, Back Focal Lenght, MTF function for convex and concave lens measurements.
Lens centration errors are measured by rotating sample over it‘s axis. Measurements are performed either in reflection or in transmission modes.
Price list
| Test | Description | Price per sample, Euro* | |
| 1 | Visual inspection (cleaning, photo) | Visualy elements are inspected under white light source, special and soft paper is used for cleaning. Stereo microscopes for small defect visualization is used, defects always are recorded by camera and included into test report. | 5 |
| 2 | Transmittance and reflectance, 190-2500 nm | Transmittance and reflectance is measured with Specord200 in the range 190-1100 nm Transmittance in the range 1000-3300 nm is measured with Shimadzu instrument |
15 |
| 3 | Transmittance and reflectance, 2500-20000 nm | Transmittance and reflectance in the range 2500-20000 nm is measured with Thermo scietific FTIR spectrometer. | 30 |
| 4 | ROC (30-5000 mm) | Lens parameters such as efective focal lenght, radius of curvature, back focal lenght, also dublets centration is measured by non contact method with combination of Opticentric and OptiSpheric instruments. | 30 |
| 5 | ROC (30-950 mm) | For interferometric measurements we use ZYGO XP/Z Fizeu interferometer. Accesories, such as transmission flats, transmission spheres and attenuator allows to to measure flatness/irregularity, wavefront distortion in transmittance for plano and spherical optics. Integrated digital radius scale is used for Radius of Curvature measurements with accuracy better than 0.1 mm. Selection of transmission spheres allows to measure both positive and negative lenses. Software gives values of Zernike coeficients (aberations), modulation transfere function, difraction data of the lenses. | 40 |
| 6 | Flatness, wavefront distortion for plano/plano optics | 30 | |
| 7 | Surface irregularity, wavefront distortion for spherical optics | 40 | |
| 8 | Angle, wedge | Wedges, prism and polygon angles are measured with goniometer GoniomatHR within accuracy of 0.5 arcsec. | 20 |
| 9 | Laser induced damage threshold | Laser induced damage threshold could be measured with femtosecond or nanosecond pulsed lasers. All measurements for “1 on 1” and “S on 1” procedures are performed according to ISO 11254 standards. Following options are available: 1064, 532, 353 nm, 3-5 ns, 1-10 Hz 1030, 515, 343 nm, 200-400 fs, 1 kHz – 200 kHz |
300-450 |
| 10 | Preparation, engineering for non-standard tests | For non-standard test we use following CW laser sources: 1030 nm, max. Power 800 mW, stability <3% 1064 nm, power 200 mW, stability <3% 532 nm, max. Power 500 mW, stability <3% 632.8 nm, power 3 mW, stability <1% |
30/hr. |
| 11 | Packing and Labeling | Vacuuming or packaging in plastic, membrane boxes with optional company logo print | On request |
* - price for quantity 1-10, price for quantities more than 10 pcs will be discussed separately For tests #2-#9 visual inspection will be done with no additional fee. |
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