For about 200 years surface shape specification for optical components always had one goal only, to make an individual
optical component comparable with other pieces of the same type. If the specification is met, the component should
fulfill the requested behavior in the related optical system. Nomenclature of specification did not differ in dependence on
the components different position in the system or on different used beam diameters vs. components clear aperture. With
increasing performance of designed optical systems, surface shape tolerances of components became tighter more and
more. Such requirements either lead to inadequate expenses or to the absence of equipment to manufacture and test them
in a controlled process.
But in reality, only a small part of optical system components are used as they are measured - within full clear aperture.
Moreover, the light beam has a significant smaller diameter than the clear aperture has. Typically, this kind of
components we find in scanning systems and lenses with large Field of View (FOV).
As far as designed surface shape tolerances are derived from maximal acceptable wave front deviation for individual
light beams passing through the system, the related method for optical components acceptance test procedures is to
analyze wave front deviation in sub apertures caused by surface shape deviation. In this case designed values and
manufactured results are comparable to each other. To get the comparable values, surface shape analysis must be done in
a gliding sub-aperture area instead of analysing full clear aperture.
We show how sophisticated optical systems components may be specified, manufactured and tested in gliding subaperture
areas for any term described in normative papers, such as ISO
10110-Part 5 "Surface Form Tolerances", to
assure the final function in system.
The chosen examples correspond with "classic specified" optical component surface shapes down to 3/ - (0.02)@546nm.
Computer generated holograms (CGH) are widely used in combination with standard Fizeau interferometers. The test of plane and spherical specimen is extended to the test of aspherical surfaces. The wave from a transmission flat or a transmission sphere is formed by the CGH to fit the surface of an asphere or a cylinder. There are some considerations for an advantageous design of this additional optical element in the beam path. The availability of a suitably designed CGH is often the limitation for the manufacturing of precision aspheres. JENOPTIK Laser, Optik, Systeme GmbH can provide a custom made CGH within a short time. We will show the design principles and the layout of the CGHs. The optical properties and the known limitations will be presented based on measurements of aspherical surfaces.
With computer generated holograms (CGH) the testing possibilities of interferometers for plane and spherical specimen is widened to the test of aspherical surfaces. The wave from a transmission flat or a transmission sphere is formed by the CGH to fit the surface of an asphere or a cylinder. The availability of suitable CGHs is often the limitation for the production of precision aspheres. JENOPTIK L.O.S. can provide a custom made CGH within a short time. We will show the design principles and the layout of the CGHs. The optical properties and the known limitations will be presented on the basis of measurements of aspherical surfaces.
The paper deals with challenges, solutions and results obtained by JENOPTIK Laser.Optik.Systeme GmbH (JO L.O.S.) while contriving and transferring knowledge gained in the field of manufacturing and testing high-end spherical and plan surfaces into manufacturing of complex optical surface shapes. During the last two years notable progress was made in the field of manufacturing optical components with constantly changing curvature and lack of symmetry by linking selected manufacturing equipment and testing methods to each other. We will show present results reached in industrial manufacturing of complex surface shapes on an accepted level of expanse.
Laser micromachining is mostly based, so far, on Q-switched laser sources. Their nanosecond pulse width often limits the accuracy and quality of laser processes by thermally initiated effects. Precision micromachining benefits from ultra short laser pulses. Up to now mostly amplified fs lasers with low repetition rates were used, with the result of low processing speed. New diode pumped solid-state picosecond lasers can also meet the demands of precise micro-machining. Their pulse duration of about 10 picoseconds provide the optimum performance e.g. for metal processing. These lasers also provide high average powers and much higher repetition rates of more then 100 kHz to maximize throughput. New potentials of picosecond lasers for the processing of different materials with high precision and increased speed will be discussed.
A small distinction of some micron makes an awful difference between spheres and aspheres. It takes special technological equipment to manufacture and test aspheric optics. This equipment is clearly distinguished from that for classical optics manufacturing. This paper deals with equipment installed at JENOPTIK L.O.S. and give results based on serial manufacturing of aspheres.
Testing aspheric surfaces by interferometer set-up together with a NULL-Computer Generated Hologram (NULL-CGH) is a well-established method. Nevertheless, this method is used in industrial manufacturing environs only frequently yet due to certification issues, cost dependence on laboratory-intensive equipment and highly specialized skills that are required to perform Null-tests for aspheric surfaces. On the other hand there is no widely accepted alternate method to feedback the aspheric test surfaces's shape error to the workmanship during fabrication of aspherics. This paper deals with results obtained by testing aspheric surfaces in industrial manufacturing environs with CGH of different production accuracy.
Light scattering measurements are important tools for characterizing optical surfaces can basically be divided into two main groups: total scatter measurements (TS) and Angle Resolved Scattering (ARS). Since TS measurements are fairly straight forward and widely used, international standardization has formulated an international draft standard on it, ISO/DIS 13696. ARS is a more complex method and not as common as TS measurements. However ARS data in form of the Bi-directional Reflectance Distribution FUnction (BRDF) can be used to predict stray light in Laser and Industrial Optical Systems. Because of increasing importance of this topic the EC is sponsoring a project regarding 'Standard procedures for stray light specification, measurement and testing - SLIOS'. During the project two of the activities are: performing a round robin experiment of measuring BRDF data at 5 different sites including some complementary techniques; compiling of an open access data base of measured BRDF data, measured according to procedures agreed upon between the SLIOS partners and proposed for 'Standard Procedures'. Results of these two activities will be presented.
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