Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).
Session Chair: Marco Hanft, Carl Zeiss AG, Germany
Location:Room 21 (ICM, 2nd Floor)
14:00 - 14:15 ID: 168 / S03: 1 Manufacturing, Tolerancing, and Testing of Optical Systems (MOS)
Direct Laser Fabrication of Cylindrical Lenses in Wide Band Gap Materials
Sebastian Buettner, Michael Pfeifer, Steffen Weissmantel
Laserinstitut Hochschule Mittweida, Germany
The Fluorine laser microstructuring technique enables the direct laser fabrication of cylindrical lenses and lens arrays thereof in wide band gap materials. For the mask projection technique, a special mask geometry was calculated, which allows the fabrication of cylindrical lenses with a nearly optimum curved surface. Based on our results of processing fused silica and borosilicate glass, we investigated the possibility to apply these microstructuring technique to wide band gap materials like calcium fluoride. The radius of curvature (ROC) can be adjusted by the process parameters laser pulse fluence and pulse-to-pulse overlap in a range of 130 to 450 μm micrometer. A minimal surface roughness of 100 nm RMS can be reached.
14:15 - 14:30 ID: 155 / S03: 2 Manufacturing, Tolerancing, and Testing of Optical Systems (MOS)
Nopt - New Polishing Techniques for Scalable, Light-weighted Mirrors of Different Materials
Sebastiano Spinelli1, Luigina Arcangeli1, Ruben Mazzoleni1, Massimiliano Rossi1, Marco Terraneo1, Roman Windpassinger2
1Media Lario Srl, Italy; 2ESA ESTEC, The Netherlands
In the framework of an assessment of optical polishing techniques, ESA has signed a contract with Media Lario to deliver two 250 mm mirrors with a common optical design to be polished down to very tight surface requirements. NOPT mirrors are respectively made of Zerodur and RSA443 aluminium alloy with electroless nickel and will they be polished by means of bonnet polishing. Mirrors are light-weighted up to 20kg/m2; the mechanical and optical design is proven to be scalable up to 1m CA surfaces. This paper reviews the mirrors opto-mechanical design, introduce the polishing and metrology strategy while highlighting the differences and the common point in fabricating such mirror in Zerodur and metal.
14:30 - 14:45 ID: 157 / S03: 3 Manufacturing, Tolerancing, and Testing of Optical Systems (MOS)
Optical Freeform Generation by Laser Machining and Plasma-assisted Polishing
Thomas Arnold1,2, Anne Maiwald2, Georg Boehm2, Martin Ehrhardt2, Klaus Zimmer2
1Institut für Fertigungstechnik, Fakultät Maschinenwesen, Technische Universität Dresden, Germany; 2Leibniz-Institut für Oberflächenmodifizierung e.V., Germany
Tailored optical freeform lenses are required for different applications .Sub-aperture deterministic machining techniques such as plasma jet machining have shown great potential to generate freeform surfaces. However, depending on the required local slopes of the surface shape geometrical limitations occur due to the lateral tool function width. In the paper an alternative approach to fabricate freeform shapes exhibiting steep local slopes is presented. A first step involves a dwell time based fs-laser ablation process to generate the surface contour on a fused silica sample. Since the resulting roughness after laser machining lies in the range of 400 nm RMS which does not match optical requirements a subsequent plasma jet based polishing step is performed where micro-roughness is drastically reduced to values below 0.25 nm RMS.
14:45 - 15:00 ID: 144 / S03: 4 Manufacturing, Tolerancing, and Testing of Optical Systems (MOS)
Realization Of Depth Reference Samples With Surfaces Amplitudes Between 0.1 nm and 5 nm
Annemarie Finzel, Gregor Dornberg, Stephan Görsch, Martin Mitzschke, Jens Bauer, Frank Frost
Leibniz Institute of Surface Engineering (IOM), Germany
A new approach for the realization of depth reference samples is presented. By a combination of photolithography, reactive ion beam etching, surface planarization with photoresists and a subsequent coating with non-transparent materials, defined sinusoidal surface profiles are generated which can be used as depth references for the comparison and calibration of different surface profile measurements. The smallest realized surface amplitudes are in the range of less than 0.1 nm.
15:00 - 15:15 ID: 125 / S03: 5 Manufacturing, Tolerancing, and Testing of Optical Systems (MOS)
Transient Dynamics Measurement of Light-material Interaction for Laser Optics
Fine Optics Engineering Research Center, China, People's Republic of
Laser damage performance is an important parameter to evaluate the quality of high power laser optical components. Understanding the physical mechanism of the interaction between laser and optical material is of great significance for improving the laser damage resistance of optical elements. For nanosecond pulsed laser, the time duration of laser-induced damage is ultra-short, and the measurement of related physical quantities is very difficult. Therefore, the Time Resolved Pump and Probe (TRPP) technique can effectively solve this problem. TRPP shadow imaging can obtain the transient dynamic information in range of picosecond to microsecond, including the plasma formation in the early stage, the shock wave propagation, the crack expanding, material ejection and other phenomena. Moreover, the ultra-fast physical quantities can be accurately measured by employing two detective beams with perpendicular polarization directions, for example S and P polarization light. All those information provides effective experimental data to reveal the physical mechanism of damage process.