OptiCentric® METRO for Operations in Metrology
OptiCentric® METRO instruments are designed to measure centering errors and other parameter of lenses and optical systems. All instruments of METRO Series can be used to carry out measurements using the reflection mode and/or transmission mode, an exception being the OptiCentric® SMART which only works in reflection mode.
OptiCentric® METRO is of modular design, so that the instruments are upgradeable and compatible with each other. To make the selection of the suitable equipment easier, the main instrument parts and configurations are presented:
OptiCentric® MOT 100
OptiCentric® MOT 300 UltraStable
OptiCentric® MAX UP
Infrared Lens Measurement with OptiCentric®
Extension Modules, OptiCentric® MOT[/tab]
[tab name=”OptiCentric® Principle Setup”]Optical Measuring Head
The optical measuring head of the instrument is designed to view and quantify the size of the centering error in single and multiple optical components. It is also the basic unit used for alignment of single elements before cementing or mounting in cells.
This is usually an autocollimator equipped with additional head lenses which is focussed in the image plane of the sample (transmission method) or in the centre of curvature of the lens surface under test (reflection method).
Stands with Travel Mechanism or Motorized Stages
The optical measuring head is mounted on a stand having capabilities to move up and down in order to adapt to a certain range of radii of curvature (for Reflection Mode) or of focal length (for Transmission Mode).
Depending on applications OptiCentric® METRO provides a large variety of sample holders: self-centering holders, vacuum retention devices, hydrostatic chucks, three jaws chucks, etc.
Lens Rotation Devices
Since the viewing and the measurement of the centering errors are only possible when the lens is rotated (except for extremely expensive errorless focusing devices), the availability of a lens holding and rotary device is crucial for completing a centering measurement.
The accuracy of the centering measurement and of the alignment/mounting of lenses is determined by the two basic components of a entering/mounting equipment:
- Optical measuring head
- Lens Rotation Device
Many optics manufacturers underestimate the importance of the Lens Rotation devices in ensuring the required accuracy. Since the use of accurate CCD-cameras and complex image processing software provides a high accuracy of optical measuring heads, the largest error source in lens centring and mounting is in many cases the Lens Rotation Device. Many of the Lens Rotation Devices used in the optical manufacturing do not provide a reference rotation axis which is enough accurate and stable.
TRIOPTICS invested a large amount of work in designing a complete range of accurate devices for lens rotation:
- Motorized Vacuum-Lens Rotation Device
- Ultra-Precision Air Bearing Rotary Table
- Mechanical and Hydrostatic Lens Holders