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.
Shack-Hartmann wave front sensors (SHS) are an accurate and highly versatile tool for
characterizing and adjusting high performance optical systems, especially in the DUV
The conventional set-up uses a single path approach. An illuminated pinhole is placed in the
object plane and the sensor in the exit pupil of the system under test. This approach is applicable
up to a NA of about 0.9 because of the limited ability of a pinhole to illuminate high numerical
apertures. Beyond the limit a double pass set-up is necessary. The double pass approach also
allows a higher precision and the application of multi-position tests well-known from
A set-up will be shown which can be easily integrated into existing Shack-Hartmann test
benches. Some exemplary data will be given comparing results from single pass and double pass
The fast development of sensors with high sensitivity and growing pixel numbers for the IR range drives the
development of suitable optical systems. This is enforced by the growing demands of the defense and security sector.
JENOPTIK LASER, OPTIK, SYSTEME GmbH serves this market based on many years of experience. The product
spectrum contains all usual types of optical components. Most of the typical IR transmitting and reflecting materials are
machined. The quality scale reaches from medium to high-end, where the latter is mostly needed for defense
applications. High-efficiency, highly durable and environmentally stable anti-reflection coatings for the complete
spectrum of substrate materials are developed and produced in-house. JENOPTIK is developing and manufacturing
custom-tailored lens systems and electro-optical modules for civil and military applications. This includes optical
modules for IR cameras and for long range surveillance and target recognition, which fulfill the highest demands with
respect to imaging quality, aperture, stray light, compactness, and durability. The testing and the verification of
performance parameters include interferometrical testing, transmission, scattering, and MTF measurement at working
temperature. A combination of design, manufacturing and measurement techniques is needed for the fabrication of IR
lens systems meeting the highest performance requirements.
Aside from steppers also inspection systems in the semiconductor industry as well as in micro
material processing require DUV imaging optics with very high optical requirements.
A test and adjustments set-up based on the Shack-Hartmann wave front sensor for objectives
and telescopes is presented. It allows primarily to characterize the image quality of systems
under test for both finite as well as infinite object and image distances.
From the wave front the modulation transfer function, point spread function or encircled
energy data can be derived. Also, other data such as magnifications, focal lengths and even
distortion with micrometer accuracy can be obtained with the test bench.
The test system consists of a spherical waves generator, the sensor including adapting optics
and the mechanical motion system. It is highly motorized and all essential functions are
computer controlled. The available wavelengths currently range from NIR to 193nm.
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.