Journal Articles, Book Chapters

Results: 195
Created on: Thu, 28 Mar 2024 23:05:01 +0100 in 0.0478 sec


Hofmann, Meike; Müller, Ralf; Stoebenau, Sebastian; Stauden, Thomas; Brodersen, Olaf; Sinzinger, Stefan
Integrated optofluidic system for monitoring particle mass concentrations based on planar emitter-receiver units. - In: Applied optics, ISSN 2155-3165, Bd. 51 (2012), 32, S. 7800-7809

We demonstrate an integrated optofluidic system for monitoring the particle mass concentration and the Sauter mean diameter of polydisperse flowing suspensions of water and standardized test dust. For optimum integration, a planar emitter-receiver unit is developed and fabricated an Si technology. A vertical cavity surface emitting laser at 850 nm serves as light source, and monolithically integrated segmented photodiodes detect both the attenuation of the primary light beam und the scattered light. The optical system is integrated into a planar transparent polymethylmethacrylate substate by micromilling of an optical freeform surface and electron beam evaporation of reflective layers following the concept of planar integrated free-space optical systems. We are able to detect 1 mg/L of standards ISO 12103-A2 (fine test dust), -A3 (medium test dust), and -A4 (coarse test dust) and to determine the Sauter mean diameter of the particle size distribution.



https://doi.org/10.1364/AO.51.007800
Sabitov, Nail; Meinecke, Thomas; Kelly, Damien Peter; Sinzinger, Stefan
Two-step phase-shift interferometry with known but arbitrary reference waves: a graphical interpretation. - In: Applied optics, ISSN 2155-3165, Bd. 51 (2012), 28, S. 6831-6838

There are many applications in biology and metrology where it is important to be able to measure both the amplitude and phase of an optical wave field. There are several different techniques for making this type of measurement, including digital holography and phase retrieval methods. In this paper we propose an anylytical generalization of this two-step phase-shifitng algorithm. We investigate how to reconstruct the object signal if both reference waves are different in phase and amplitude. The resulting equations produce two different solutions and hence an ambiguity remains as to the correct solution. Because of the complexity of the generalized analytical expressions we propose a graphical-vectorial method for solution of this ambiguity remains as to the correct solution. Because of the complexity of the generalized analytical expressions we propose a graphical-vectorial method for solution of this ambiguity problem. Combining our graphical method with a constraint on the amplitude of the object field we can unambiguously determine the correct result. The results of the simulation are presented and discussed.



https://doi.org/10.1364/AO.51.006831
Abd El-Maksoud, Rania H.; Hillenbrand, Matthias; Sinzinger, Stefan; Sasian, Jose
Optical performance of coherent and incoherent imaging systems in the presence of ghost images. - In: Applied optics, ISSN 2155-3165, Bd. 51 (2012), 30, S. 7134-7143

Ghost image analysis is of interest for optical designers as ghost images may degrade image quality in imaging systems. In a previous paper by Abd El-Maksoud and Sasian (Appl. Opt. 50, 2305 (2011), ghost image analysis for incoherent systems was evaluated using geometrical optics. Some criteria were presented to identify focused ghost images at the nominal image plane. The main goal of this paper is to provide a conceptual understanding of ghost image formation and its impact on the performence of imaging systems using wave theory and Fourier optics. To achieve this goal, a methodology is developed to model ghost images after considering diffration effects. Expressions for the ghost diffraction point spread function and the ghost transfer functions. To provide insights on the developed theory, some simulation examples are provided and discussed.



https://doi.org/10.1364/AO.51.007134
Sinzinger, Stefan; Oeder, Andreas; Stoebenau, Sebastian; Kampmann, Ronald
Compact optical systems for micromanipulation : bringing optical tweezers into industrial applications. - In: Laser-Technik-Journal, ISSN 1863-9119, Bd. 9 (2012), 4, S. 20-23

https://doi.org/10.1002/latj.201290047
Sinzinger, Stefan; Cahill, Brian; Metze, Josef; Hoffmann, Martin
Optofluidic microsystems for application in biotechnology and life sciences. - In: Optical Nano- and Microsystems for Bioanalytics, (2012), S. 305-323

http://dx.doi.org/10.1007/978-3-642-25498-7_12
Hillenbrand, Matthias; Mitschunas, Beate; Wenzel, Christian; Grewe, Adrian; Ma, Xuan; Feßer, Patrick; Bichra, Mohamed; Sinzinger, Stefan
Hybrid hyperchromats for chromatic confocal sensor systems. - In: Advanced Optical Technologies, ISSN 2192-8584, Bd. 1 (2012), 3, S. 187-194

The combination of diffractive and refractive elements in hybrid optical systems allows for precise control of the longitudinal chromatic aberration. We provide comprehensive design strategies for hybrid hyperchromatic lenses that maximise the longitudinal chromatic aberrations. These lenses are mainly used in chromatic confocal sensor systems for efficient non-contact profilometry as well as for measurements of distances and wall thicknesses of transparent materials. Our design approach enables the tailoring of the sensor properties to the specific measurement problem and assists designers in finding optimised solutions for industrial applications. We, for example, demonstrate a hybrid system that significantly exceeds the longitudinal chromatic aberration of purely diffractive elements.



http://dx.doi.org/10.1515/aot-2012-0017
Hofmann, Meike; Kampmann, Ronald; Kampmann, Ronald *1981-*; Sinzinger, Stefan;
Perturbed Talbot patterns for the measurement of low particle concentrations in fluids. - In: Applied optics, ISSN 2155-3165, Bd. 51 (2012), 10, S. 1605-1615

https://doi.org/10.1364/AO.51.001605
Sinzinger, Stefan;
Laser-Pinzette der TU Ilmenau gewinnt renommierten Optikpreis. - In: Laser-Magazin, ISSN 0945-8875, (2012), 1, S. 21-22

Die Technische Universität hat für die Entwicklung einer innovativen optischen Pinzette den renommierten Edmund Optics Research-Preis gewonnen. Die Pinzette greift, hält und positioniert Mikropartikel, ohne sie zu berühren.



Oeder, Andreas; Stoebenau, Sebastian; Sinzinger, Stefan
Optimized free-form optical trapping systems. - In: Optics letters, ISSN 1539-4794, Bd. 37 (2012), 2, S. 274-276

http://dx.doi.org/10.1364/OL.37.000274
Baer, Michael; Kleindienst, Roman; Sinzinger, Stefan
Replikation diffraktiver optischer Elemente aus synthetischem Quarzglas nach dem Sol-Gel-Verfahren. - In: Photonik, ISSN 1432-9778, Bd. 43 (2011), 6, S. 38-41

Durch Abtasten der Rayleigh-Streuung entlang einer Standardsglasfaser lässt sich ein verteilt messendes Sensorsystem realisieren, bei dem jeder Faserpunkt als Sensor wirkt. Dieses neuartige Verfahren ermöglicht quasi-kontinuierliche Messungen von Temperaturen- und Dehnungsprofilen über Strecken bis 70m. Die räumliche Auflösung liegt dabei im Milimeterbereich, was tausenden konventioneller Punktesensoren entspricht.