Jenoptik (Germany)

Tactile industrial measuring instruments are frequently calibrated with material measures defined in ISO 5436–1 to ensure their function, determine their measurement uncertainty and assess the capability of measuring processes. Since these process needs to be repeated on a regular basis, the long-term stability of both material measures and the stylus is essential to enable a repeatable and reliable measurement. Since the tactile sampling of a material measure involves a mechanical interaction, there is the potential for wear when repetitive measurements are performed. We present a comprehensive experimental study on the effects of wear for different stylus instruments – including a reference plane scanning system and multiple skidded scanning systems. Multiple measurement methods are used to determine the state of the stylus and the surface of the material measure, both before and after their mechanical interaction. The impact of the wear on the accuracy of the results can be described, as can the connection between the wear and the hardness of the skidded probe. The study found that significant wear effects on surfaces with even >500 HV become qualitatively visible much earlier than they can be quantitatively detected, with extreme load cases of >1000 repetitive measurements at the same position being necessary to produce major wear influences. Thus, regular visual inspections in case of extensive repetitive measurements can be recommended, just as well as a low measuring force and a reduction of the number of measurements for measurement capability analysis to 12 measurements.

Two-dimensional hexagonal VCSEL arrays with up to 37 VCSELs per array and emitting at 940 nm to 1020 nm are produced on GaAs substrates. Arrays with variable oxide aperture diameters and new processing geometries, with a focus on optimizing the tradeoffs in optical output power, bandwidth, power conversion efficiency, and emitted far field pattern for applications in optical wireless communications are characterized and compared. Standard on wafer probing and packaged array tests are performed including terrestrial free space measurements demonstrating the viability of the core VCSEL array technology for fifth, sixth, and next generation optical wireless systems.

Publisher’s Note: This conference presentation, originally published on 11 March 202, was withdrawn on 3 June 2020 per author request.

We show our latest results on electrically-driven VCSELs incorporating a monolithic high contrast grating (MHCG) mirror. Via optimized processing techniques we achieve a 3-fold improvement in threshold current and optical output power and a 2-fold improvement in the small-signal modulation bandwidth frequency with respect to the first generation of our MHCG VCSELs.

We investigate triple and septuple electrically parallel, optically uncoupled 980 nm vertical-cavity surface-emitting laser (VCSEL) arrays with varying intra-array VCSEL-to-VCSEL spacings and oxide aperture diameters. We demonstrate 20 to 40 gigabit-per-second back-to-back data transmission with a bit error ratio of 1x10-13. Our VCSELs enable optical wireless communication for a plethora of sensors, smartphones, and other Internet of Things gadgets.

Within the modern production of high-precision optics, Ion Beam Figuring (IBF) is an established machining process. IBF uses an ion beam with a Gaussian particle distribution. Atoms are sputtered from the workpiece surface by accelerated ions. Compared to other correction methods (e.g. MRF) IBF provides a significantly smaller tool, enabling precise and deterministic results. The machining takes place contactless in vacuum. Thus the technology qualifies for many unique application possibilities in the production of high performance optics. After a brief introduction to the basics of IBFtechnology, this article features various industrial applications: The nanometer accurate correction of optical surfaces, the correction of angular errors as well as smoothing, structuring and decoating of lenses will be presented. Focus of the lecture is the improvement of wavefronts in optical systems using IBF-processed correction surfaces. The complete process is presented and illustrated with examples and results.

The refractive index of germanium is known only up to the third decimal according to publicly available sources. This data from various authors shows deviations in the order of several 10^-3 not to be explained by experimental errors of the refractive index measurement. This is a strong indication that there is optically relevant material property variation. We present an interferometric method to measure the refractive index and its temperature dependency on etalon samples, which are cheaper to prepare with high quality than prism samples needed for the classical method of index measurement. Resolution and stability of our method is better than 10^-4. The method can be used for both germanium and silicon. Our goal is to be able to produce material with optically relevant specifications. This is in contrast to the conventional method of specifying these important IR-optical materials in terms of electrical properties such as dopant type and concentration.

Laser stacks emitting short light pulses are ideally suited for medical and cosmetic applications. Developing enhanced, stable and reliable assembly processes, Jenoptik is reaching for higher energy densities and lower manufacturing costs. In this paper an improved technology for actively cooled QCW stacks is presented. Based on simulations and experimental data, the impacts on the laser stack performance are described and shown as power-current and thermal impedance plots. We show that the bar-to-bar pitch can be reduced from 1.7 mm to 1.2 mm without detrimental thermal effects for pulse durations up to 100 ms.

Optik & PhotonikVolume 10, Issue 2 p. 1-1 EditorialFree Access A Powerful Tool Light will strengthen the European economic backbone Dr. Michael Mertin, Dr. Michael Mertin Jenoptik AGSearch for more papers by this author Dr. Michael Mertin, Dr. Michael Mertin Jenoptik AGSearch for more papers by this author First published: 13 April 2015 https://doi.org/10.1002/opph.201590028AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue2April 2015Pages 1-1 RelatedInformation