Centering Error Measurement and Optical Alignment

OptiCentric_MOT_100Inspection, Alignment, Cementing and Assembly of Optics

According to ISO 10110 a centering error is present when the optical and the reference axis of a lens do not coincide, respectively these are different in position or direction.

During the process of cementing, alignment and bonding of lenses in a mount, significant centering errors can result and add to the machining errors of a lens. Consequently, the requirements of a high performance optical system can only be fulfilled when all the production steps from the centering tolerance measurement to the assembly of the lens in a mount are planned and designed as an integrated concept.

The modular TRIOPTICS product group OptiCentric®is able to measure nearly all types of lenses and optical systems from the tiniest and smallest endoscope systems to precision objectives weighting several hundred kilos for wafer steppers in the semiconductors industry.

The products of the OptiCentric® range are subdivided into:

OptiCentric® METRO – for Metrology and comprehensive measurement of optical systems

The capabilities of OptiCentric® METRO are not limited to the measurement of lens centration errors. Various enhancements and additional modules allow for measurement of many other optical parameters to be presented at the following pages.


OptiCentric® PROOptiCentric_MAX_UP – for Production and Assembly of objective lenses

OptiCentric® Max UP
The Ultimate Solution for Alignment, Assembly and Final Inspection of Microlithography Optics

  • Ultra accurate measurement of centration error, lens center thickness and air spacing
  • All-granite, all-air bearing construction provides exceptional rigidity and thermal stability, smooth motion and unrivaled accuracy
  • Additional alignment unit equipped with heavy duty piezoelectric actuators provides automated alignment with submicron accuracy
  • Specifically designed for microlithography and space optics with diameter up to 800 mm, height 2,000 mm and weight 1,500 kg

OptiCentric 3D IR
OptiCentric® 3D IR provides an ideal solution for the complete optomechanical characterization of assembled IR optical systems. The instrument integrates different lens analysis technologies and provides a valuable tool for the evaluation of complex optical systems in R&D and quality control in production environments.


Technical Informational Brochures & Videos

pdf OptiCentric® PDF Brochure
pdf Infrared Lenses Measurement with OptiCentric®
pdf OptiCentric® MAX UP Bonding PDF Brochure
pdf OptiCentric® Cementing PDF Brochure
pdf OptiCentric® 3D PDF Brochure
pdf OptiCentric® Modular System PDF Brochure

Automatic Bonding with OptiCentric® – single alignment axis


Automatic Bonding with OptiCentric® – 120° three alignment axis

OptiCentric® Cementing Station

OptiCentric® Bonding Station

OptiCentric® Bonding Station

The TRIOPTICS comprehensive line of equipment under the generic name OptiCentric® has been specifically designed to cover applications related to any type of optical components and to respond to different accuracy degrees. The OptiCentric® System also covers all the production steps from the centration measurement to the alignment, cementing and assembly of optics. OptiCentric® includes valuable tools for any application, from simple and affordable visual instruments to complex, fully automated and PC-controlled production and laboratory stations.

Application overview

Application overview










OptiCentric® Product Range in Operation

Measurement tool for miniature lenses

Measurement tool for miniature lenses

The products of the OptiCentric® range are subdivided into:

OptiCentric®METRO – for Metrology and comprehensive measurement of optical systems

OptiCentric® PRO – for Production and Assembly of objective lenses



Simultaneous measurement in reflection of both lens surfaces

Simultaneous measurement in reflection of both lens surfaces

The advanced software is designed to work with Windows XP operating systems. The software fulfils the need of the optical shop for easy, intuitive operation and features a number of options to accommodate a large variety of specific requirements.

The software modules “Centration in Transmission” and “Centration in Reflection” provide an outstanding accuracy even in difficult measuring situations such as poor contrast, anti-reflection coated surfaces, very small lenses, etc. With the OptiCentric® Dual Head instrument the software optionally provides simultaneous measurement data with two live images for both lens surfaces. The software features selectable options to adapt the system to different hardware configurations e.g. different reticule patterns (bright cross, dark cross, pinhole, etc.). Several different measurement units like mm/inch, arcsec, microradians, etc. can be selected. To increase the production efficiency, the optimized process parameters can be saved for future use.

Measurement of radii of curvature

Measurement of radii of curvature

Additional features of the software

  • Real time monitor display of the camera image from one or two measuring heads
  • Real time, continuous display of the measurement values
  • Vector display of the size and direction of the centering error
  • HTML certificate output
  • Computer generated tolerance circles or angle graduations for the quick analysis of production quantities
  • Automatic adjustment to the sample reflectivity
  • Automatic calibration procedure by means of a calibrated sample, the calibration can be verified at customer site
  • Artificial crosshair for the initial alignment assistance

The following accessories are offered to extend the use of OptiCentric® instruments.

Motorized Centering and Cementing equipment with vacuum chuck

Motorized Centering and Cementing equipment with vacuum chuck

Motorized Centering and Cementing Equipment with Vacuum Chuck

The vacuum unit is a rotation device to measure the centering error of single lenses with the outer edge as the reference. The lens is rotated using a motor-driven friction wheel against a V-block. The lens is held in position by vacuum.

The control of all functions such as the pressure, rotational speed and vacuum pump is integrated in one control unit. A compressed air line system is not required. The vacuum rotation fixture exhibits an excellent level of accuracy and reproducibility. Possible errors relating to the roughness of the outer cylinder are averaged out so that the results have a very high repeatability.

The maximum sample diameter for measurements with the standard vacuum unit is 75 mm. A modified unit for measuring samples up to 210 mm diameter is available. The vacuum unit is the standard tool of OptiCentric® MAN instruments but may be purchased as an accessory for OptiCentric® MOT to enable lens cementing.

Extension of Measurement Range

Measuring range of the OptiCentric® system is limited by the size of the upper surface radius when measuring in reflection mode or the effective focal length when measuring in transmission mode. TRIOPTICS provides a set of additional head lenses to extend the range of radius and focal length up to ± 2000 mm. On request special lenses can be provided for larger values. Plano surfaces (radius = ∞) can be measured at any time with the bare autocollimator using the parallel optical path by removing the head lenses.

Measuring Sensor and Linear Measuring Gauge

On request different mechanical measuring gauges are supplied with the OptiCentric® instrument. Following gauges are available:

Measuring lens barrel with the lever gauge

Measuring lens barrel with the lever gauge

  • A gauge for the linear stage of the measurement head to measure its position with ±2 μm accuracy. The length of the linear measuring scale is aligned with the track of the OptiCentric® system. This gauge is required for precision measurement of radius of curvature or thickness.
  • A lever gauge (Force 0.02 N, measurement range of 0.6 mm, repeatability 0.1 μm) is used to measure or align sample housings with respect to the axis of rotation.
  • A mechanical gauge with absolute accuracy of 0.2 μm and measurement range of 25 mm. It is used for alignment purposes, too.


Alignment Set

In order to align sample holders or directly adjust the sample barrel and housing, a set with two high-precision parallel flats (25 and 50 mm diameter) and two glass balls with diameters of 4-12 mm and 14-28 mm is offered.


Every OptiCentric® system is provided with a suitable light source. This is usually a 150 W halogen cold-light source with a 1 m optical fibre light guide. All TRIOPTICS autocollimators and collimators are fitted with a standard interface for the illumination so that various light sources can be exchanged for one another. The following light sources are available:

  • 150 W cold-light source with light guide
  • 250 W cold-light source with light guide
  • 20 W halogen lamp mounted directly on the autocollimator lighting assembly for increased IR output
  • 5 W filament bulb
  • 100 and 300 mW high-power light emitting diodes (LED)

Every collimator and autocollimator is also fitted with a spectral filter. Depending on the application a green or white light filter is applied.

For the measurement of IR optics TRIOPTICS provides a measurement head developed for measurement tasks in the IR range.

Revolving Turret

The turret is recommended for the quick and simple change of the head lenses. OptiCentric® offers a manual 4x changer and a motorized 6x changer. On request both changers can be supplied assembled on the measuring head.

Calibration Tool

TRIOPTICS offers calibration wedges for the regular inspection of the measurement accuracy of the OptiCentric® system. The certified wedge angle is traceable back to international standards. The wedge angle is certified to an accuracy of 1 arcsecond.


OptiCentric® Instruments Order Numbers
OptiCentric® MAN *
OptiCentric® MAN – / 250 / Single Head 4-100-02
OptiCentric® MAN – / 400 / Single Head 4-103-02
OptiCentric® MOT *
OptiCentric® MOT – / 225 / Single Head 4-400-02
OptiCentric® MOT – / 225 / Dual Head 4-405-02
OptiCentric® MOT 100 / 225 / Single Head 4-400-02 + 4-300-49
OptiCentric® MOT 100 / 600 / Single Head 4-401-06 + 4-300-49
OptiCentric® MOT 100 / 225 / Dual Head 4-405-02 + 4-300-49
OptiCentric® MOT 100 / 600 / Dual Head 4-405-06 + 4-300-49
OptiCentric® MOT 300 *
OptiCentric® MOT 300 / Single Head 4-401-08 + 4-305-49
OptiCentric® MOT 300 / Dual Head 4-405-60 + 4-305-49
OptiCentric® MAX
OptiCentric® MAX 300 4-143-00
OptiCentric® MAX 600 4-146-00
OptiCentric® SMART
OptiCentric® SMART / Single Head 4-139-00
OptiCentric® SMART / Dual Head 4-139-00 + 4-141-00
OptiCentric® 3D 4-151-00

* OptiCentric® bearing / max sample diameter / head


Extension Moduels Order Numbers
MultiLens® 4-400-90
AdvancedAnalyzer 4-400-91
AspheroCheck® 4-400-99
CylinderCheck® 4-300-074
OptiSurf® on request
OptiSpheric® 4-600-380
Measurement of plano optics 4-600-240


Accessories Order Numbers
Motorized lens rotation device with vacuum Chuck 4-400-90
Extension of measument range 4-400-91
Alignment tool set 4-400-99
Manual revolving turret 4-300-074
Precision, motorized and software controlled revolving turret 4-400-86
Complete device for calibration check 4-600-380