The demand for lasers with specific intensity distributions has led to the development of high power VCSEL systems.
These consist of arrays of high power VCSELs combined with microlenses allowing for intensity distributions tailored to
the needs of each specific application.
A Shack-Hartmann based instrument has been developed for the measurement of these lenses in reflection as well as in
transmission. In addition the form tools used for the microlens production can be measured with this set up. The
comparison of measured surface profiles and optical properties with the particular design values then allows for
optimization of the manufacturing process.
Aspherical lenses are usually generated by a multi-axis computer numerically controlled machine and axis guidance
errors as well as wear and environmental influences lead to unavoidable form deviations. Therefore, the manufacturing
process is often performed iteratively with intermitting measurement steps outside of the manufacturing machine and
repositioning the sample into the machine, which is causing additional errors.
We present a new deflectometric sensor designed for the machine integration, so that the form measurement is done
inside of the manufacturing machine and errors due to the sample removal are avoided.
The compact and robust sensor is based on the deflectometry principle. It detects the deflection angle of a focused laser
beam on the surface under test and measures the local slope angle of the surface in 2D. By scanning the specimen's
surface using the machine axes and integration of the slope angles, the topography can be calculated. The angular
measurement range of +/-9.5° permits the measurement of highly aspheric surfaces, e.g. at a clear aperture of 8 mm a
maximum deviation of more than 500 μm can be measured at a resolution on the nanometer scale.
One of the most commonly performed ophthalmic surgeries is the replacement of the eye lens by a synthetic intraocular
Because of the trend to match the intraocular lens with the properties of the individual eye, intricate designs for IOLs
have been developed. Multifocal, diffractive as well as aspheric designs demand for elaborate measurement and analysis
Various measurement methods have evolved including techniques which analyze the image itself or the emerging wavefront. In order to understand the advantages of these different methods intraocular lenses of various designs have been measured and analyzed under miscellaneous conditions. Measurement results of this comparison will be presented.
With the recently emerged large volume production of miniature aspheric lenses for a wide range of applications, a new
fast fully automatic high resolution wavefront measurement instrument has been developed.
The Shack-Hartmann based system with reproducibility better than 0.05 waves is able to measure highly aspheric optics
and allows for real time comparison with design data.
Integrated advanced analysis tools such as calculation of Zernike coefficients, 2D-Modulation Transfer Function (MTF), Point Spread Function (PSF), Strehl-Ratio and the measurement of effective focal length (EFL) as well as flange focal length (FFL) allow for the direct verification of lens properties and can be used in a development as well as in a production environment.
Aspheric lenses are of increasing importance in compact imaging systems. New developments in production
technologies have led to the so called wafer level production with several thousands of lenses on a single wafer.
This high volume production demands fast testing equipment which allows for the characterization of complete imaging
systems as well as of all of its single components. In most of the cases conventional methods cannot be used to measure
single lenses or objectives in earlier production states. Although e.g. the measurement of the modulation transfer
function is a well established method for fast and accurate quality inspection of entire objectives it has its limitation for
Due to its very large dynamic range the Shack-Hartmann sensor is able to measure a very broad range of spherical and
aspherical lenses as well as partially or fully assembled objectives. With the combination of a fast high accuracy
wavefront sensor and special positioning algorithms which allow for high throughput in mass production a new flexible
instrument has been developed.
Aspheric lenses are of increasing importance in the production of compact imaging systems. High volume productions
of such imaging systems demand fast test systems to check the quality of the lenses. The measurement of the
modulation transfer function has its limitation for aspheric lenses that are used to correct a lens system for good image
quality, but does not have good imaging capabilities as a single lens. Measuring the wavefront of aspheric lenses with a
Shack-Hartmann sensor gives a flexible tool to determine the properties of the lenses. We present measurement
principle, capabilities and different configurations of the lens testing system WaveMaster® of Trioptics GmbH.
Using a high resolution two-dimensional angle sensor, 3D-Deflectometry determines the local slopes of an aspheric
surface. The sensor scans the surface in spherical coordinates thus measuring the deviation from a reference sphere.
A new fault tolerant software algorithm transfers slope information into surface topography data simultaneously
correcting for systematic errors of the instrument.
In this way various surface types can be characterized; convex and concave standard shapes as well as toric or even free