Content Volume 4, Issue 2 (April 2015)

aot-2015-frontmatter2

Community

News from the European Optical Society
Page 111

Editorial

Special issue on ‘integrated photonic devices: sensors, materials, systems’
Peter O’Brien / Meint K. Smit / Christian Koos Pages 117-118

Review Articles

Silicon photonics WDM transmitter with single section semiconductor mode-locked laser
Juliana Müller / Johannes Hauck / Bin Shen / Sebastian Romero-García / Elmira Islamova / Saeed Sharif Azadeh / Siddharth Joshi / Nicolas Chimot / Alvaro Moscoso-Mártir / Florian Merget / François Lelarge / Jeremy Witzens Pages 119-145
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  • The modern miniature camera objective: an evolutionary design path from the landscape lens

    Author(s): Rob Bates
    Abstract: The modern miniature camera lens is the most prolific design manufactured today, yet its design form and origins are often not well understood. This paper illuminates the ancestry of the modern miniature camera lens by developing the lens form from
    How to cite …
    1. R. Bates, "The modern miniature camera objective: an evolutionary design path from the landscape lens", Advanced Optical Technologies, Vol. 2, 2013. http://dx.doi.org/10.1515/aot-2012-0069
  • A tutorial on plastic consumer optics

    Author(s): Michael P. Schaub
    Abstract: Consumer devices increasingly contain embedded optical systems. Many of these optical systems are based on molded plastic optical elements. This tutorial provides background on the design and manufacture of such systems. Consideration is given to the material issues
    How to cite …
    1. M.P. Schaub, "A tutorial on plastic consumer optics", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2011-0006
Plastic Optics Archive »
  • Manufacturing of a precision 3D microlens array on a steep curved substrate by injection molding process

    Author(s): Hao Zhang, Sebastian Scheiding, Lei Li, Andreas Gebhardt, Stefan Risse, Ramona Eberhardt, Andreas Tünnermann, Allen Y. Yi
    Abstract: In this study, a high volume low cost manufacturing method for microoptical microlens arrays on steep curved substrates using a microinjection molding technique was investigated. The design of the individual lenslets was performed using ZEMAX. This 3D microlens array in this study contains 1219 microlenses that are evenly distributed on its concave surface with a high fill factor. The overall field of view of this microlens array on curved substrates is more than 104°. To complete the manufacturing process, first the mold inserts were machined using a voice coil based fast tool servo technique, then the 3D microlens arrays were injection molded. The injection molding process parameters were evaluated using both experiments and numerical simulation for best molding results. In addition, both geometrical errors and optical performance tests showed that the molded polymer microlens arrays can be used in wide angle imaging applications. This study demonstrated that this combined process is capable of fabricating high precision microlens arrays at steep curved substrates at low cost. The microlens arrays created in this study have broad applications in optical, medical and biomedical domains. The success of this study provided a feasible solution for mass production of 3D microlens arrays on arbitrary substrates.
    How to cite …
    1. H. Zhang, S. Scheiding, L. Li, A. Gebhardt, S. Risse, R. Eberhardt, A. Tünnermann, and A.Y. Yi, "Manufacturing of a precision 3D microlens array on a steep curved substrate by injection molding process", Advanced Optical Technologies, Vol. 2, 2013. http://dx.doi.org/10.1515/aot-2012-0061
  • Optical components and optical systems for VCSEL diode laser systems

    Author(s): Stephan Gronenborn, Michael Miller, Gero Heusler, Holger Mönch
    Abstract: High power vertical-cavity surface-emitting laser (VCSEL) arrays can be used as a versatile illumination and heating source. They are widely scalable in power and offer a robust and economic solution for many new applications with moderate brightness requirements. The use of VCSEL arrays for high power laser diode applications enables multiple benefits: full wafer level production of VCSELs including combination with micro-optics; assembly technologies allowing large synergy with LED assembly thus profiting from the fast development in solid state lighting; outstanding reliability and a modular approach on all levels. With the use of μ-lenses, the described optical principle of near field imaging and superpositioning of many thousands of VCSELs gives perfect control over intensity distribution and is inherently robust. With a slightly modified approach, lines of any desired length can be built from modules of 1-cm length and are therefore scalable for a wide range of applications.
    How to cite …
    1. S. Gronenborn, M. Miller, G. Heusler, and H. Mönch, "Optical components and optical systems for VCSEL diode laser systems", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0047
Microoptics Archive »
  • Optical properties of unprotected and protected sputtered silver films: Surface morphology vs. UV/VIS reflectance

    Author(s): Paul Johannes Jobst, Olaf Stenzel, Mark Schürmann, Norbert Modsching, Sergiy Yulin, Steffen Wilbrandt, Dieter Gäbler, Norbert Kaiser, Andreas Tünnermann
    Abstract: The optical properties of opaque sputtered silver films are investigated and related to their surface morphology. As reference, an evaporated sample produced by thermal flash evaporation has been studied, too. Standard optical and electrical characterizations as well as scanning electron microscopy (SEM) and X-ray reflectometry have been carried out with unprotected silver films directly after deposition and reveal strong correlations between the corresponding characterization results. The aging behavior of the normal incidence reflectance has been studied over a time period of 36 weeks. Protected silver mirrors have been prepared by sputtering using silica and alumina as the protective coating. It is shown by model calculations that the main spectral features occurring in the reflectance spectra of as-deposited unprotected coatings, unprotected coatings after aging, and protected coatings can be reproduced assuming a rough silver surface covered by a corresponding ultrathin absorbing interface layer or overlayer.
    How to cite …
    1. P.J. Jobst, O. Stenzel, M. Schürmann, N. Modsching, S. Yulin, S. Wilbrandt, D. Gäbler, N. Kaiser, and A. Tünnermann, "Optical properties of unprotected and protected sputtered silver films: Surface morphology vs. UV/VIS reflectance", Advanced Optical Technologies, Vol. 3, 2014. http://dx.doi.org/10.1515/aot-2013-0052
  • Dispersive mirror technology for ultrafast lasers in the range 220–4500 nm

    Author(s): Vladimir Pervak, Olga Razskazovskaya, Ivan B. Angelov, Konstantin L. Vodopyanov, Michael Trubetskov
    Abstract: Nowadays, dispersive mirrors are able to cover the wavelength range of 4.5 optical octaves and can be used from 220 nm up to 4500 nm. Various design approaches to dispersive mirrors in visible and near IR are briefly discussed. We consider in more detail two dispersive mirrors representing extreme cases. The first one is a mirror working in the range of 290−360 nm and providing group delay dispersion of -75 fs2. The second one is a mirror working in the range of 2500−4500 nm and providing +500 fs2 of group delay dispersion.
    How to cite …
    1. V. Pervak, O. Razskazovskaya, I.B. Angelov, K.L. Vodopyanov, and M. Trubetskov, "Dispersive mirror technology for ultrafast lasers in the range 220–4500 nm", Advanced Optical Technologies, Vol. 3, 2014. http://dx.doi.org/10.1515/aot-2013-0051
Optical Coatings Archive »
  • Imaging optics on scanner for SMO generation process

    Author(s): Tomoyuki Matsuyama, Yasushi Mizuno, Daniel G. Smith
    Abstract: The k1 factor continues to be driven downward, in order to enable the 22-nm feature generation and beyond. Such a low k1 factor tends to lead to extremely small process windows. For such demanding imaging challenges, it is not only necessary for each unit, contributing to the imaging system, to be driven to its ultimate performance capability, but also that active techniques that can expand the process window and the robustness of the imaging against various kinds of imaging parameters be implemented. One such technique is source and mask optimization (SMO). In this paper, we study the effect of SMO. Furthermore, we discuss how to realize the SMO solution in the imaging system setup on the scanner. The setup process includes freeform pupilgram generation (source intensity distribution on the pupil) and pupilgram adjustment.
    How to cite …
    1. T. Matsuyama, Y. Mizuno, and D.G. Smith, "Imaging optics on scanner for SMO generation process", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0032
  • Computational metrology and inspection (CMI) in mask inspection, metrology, review, and repair

    Author(s): Linyong Pang, Danping Peng, Peter Hu, Dongxue Chen, Lin He, Ying Li, Masaki Satake, Vikram Tolani
    Abstract: Mask manufacturers will be impacted by two significant technology requirements at 22 nm and below: the first is the more extensive use of resolution enhancement technologies (RET), such as aggressive optical proximity correction (OPC), inverse lithography technology (ILT), and source mask optimization (SMO); the second is the extreme ultraviolet (EUV) technology. Both will create difficulties for mask inspection, defect disposition, metrology, review, and repair. For example, the use of ILT and SMO significantly increases mask complexity, making mask defect disposition more challenging than ever. The EUV actinic inspection and AIMS™ will not be available for at least a few years, which make the EUV defect inspection and disposition more difficult, particularly regarding multilayer defects. Computational metrology and inspection (CMI), which has broad applications in mask inspection, metrology, review, and repair, has become essential to fill this technology gap. In this paper, several such CMI applications are presented and discussed.
    How to cite …
    1. L. Pang, D. Peng, P. Hu, D. Chen, L. He, Y. Li, M. Satake, and V. Tolani, "Computational metrology and inspection (CMI) in mask inspection, metrology, review, and repair", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0127
Lithography Archive »
  • The impact of the mass density on selected optical and non-optical properties of oxide coatings

    Author(s): Olaf Stenzel
    Abstract: The density of optical coatings is one of the most crucial material-related parameters in interference coating science and technology. It has an impact on the refractive index, the transparency range, and the mechanical stress of a coating material. This tutorial provides a background on the classical theory relating the coating density to the mentioned parameters. Simple models are presented that highlight the correlations between optical constants, stress, and shifting behavior of different oxide coatings. Comparison with the experiment is performed on the basis of numerous experimental data, which stem from hafnium oxide, zirconium oxide, tantalum pentoxide, and silicon dioxide.
    How to cite …
    1. O. Stenzel, "The impact of the mass density on selected optical and non-optical properties of oxide coatings", Advanced Optical Technologies, Vol. 3, 2014. http://dx.doi.org/10.1515/aot-2013-0023
  • A tutorial on plastic consumer optics

    Author(s): Michael P. Schaub
    Abstract: Consumer devices increasingly contain embedded optical systems. Many of these optical systems are based on molded plastic optical elements. This tutorial provides background on the design and manufacture of such systems. Consideration is given to the material issues, manufacturing concerns, and typical design trade-offs and constraints that often accompany plastic consumer optics.
    How to cite …
    1. M.P. Schaub, "A tutorial on plastic consumer optics", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2011-0006
Optical Materials Archive »
  • Optical design of camera optics for mobile phones

    Author(s): Thomas Steinich, Vladan Blahnik
    Abstract: At present, compact camera modules are included in many mobile electronic devices such as mobile phones, personal digital assistants or tablet computers. They have various uses, from snapshots of everyday situations to capturing barcodes for product information. This paper presents an overview of the key design challenges and some typical solutions. A lens design for a mobile phone camera is compared to a downscaled 35 mm format lens to demonstrate the main differences in optical design. Particular attention is given to scaling effects.
    How to cite …
    1. T. Steinich, and V. Blahnik, "Optical design of camera optics for mobile phones", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0002
  • Hybrid hyperchromats for chromatic confocal sensor systems

    Author(s): Matthias Hillenbrand, Beate Mitschunas, Christian Wenzel, Adrian Grewe, Xuan Ma, Patrick Feßer, Mohamed Bichra, Stefan Sinzinger
    Abstract: 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.
    How to cite …
    1. M. Hillenbrand, B. Mitschunas, C. Wenzel, A. Grewe, X. Ma, P. Feßer, M. Bichra, and S. Sinzinger, "Hybrid hyperchromats for chromatic confocal sensor systems", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0017
Optical Design Archive »
  • A practical tutorial for generating ISO 10110 drawings

    Author(s): Jason Lane
    Abstract: This tutorial provides a brief introduction to the ISO 10110 optical drawing standard. The indications included on an ISO 10110 optical drawing are defined, and an example drawing is provided to illustrate how the information is commonly presented. To aid the designer who may not be familiar with the capabilities of optical shops, a set of specification values are provided, which illustrate easy, typical, and difficult values to achieve in fabrication. The same type of information is presented for lens dimensions. Finally, a set of design best practices are presented to aid in reducing fabrication difficulty and cost.
    How to cite …
    1. J. Lane, "A practical tutorial for generating ISO 10110 drawings", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0051
Standards Archive »
  • Optical components and optical systems for VCSEL diode laser systems

    Author(s): Stephan Gronenborn, Michael Miller, Gero Heusler, Holger Mönch
    Abstract: High power vertical-cavity surface-emitting laser (VCSEL) arrays can be used as a versatile illumination and heating source. They are widely scalable in power and offer a robust and economic solution for many new applications with moderate brightness requirements. The use of VCSEL arrays for high power laser diode applications enables multiple benefits: full wafer level production of VCSELs including combination with micro-optics; assembly technologies allowing large synergy with LED assembly thus profiting from the fast development in solid state lighting; outstanding reliability and a modular approach on all levels. With the use of μ-lenses, the described optical principle of near field imaging and superpositioning of many thousands of VCSELs gives perfect control over intensity distribution and is inherently robust. With a slightly modified approach, lines of any desired length can be built from modules of 1-cm length and are therefore scalable for a wide range of applications.
    How to cite …
    1. S. Gronenborn, M. Miller, G. Heusler, and H. Mönch, "Optical components and optical systems for VCSEL diode laser systems", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0047
  • Optical coatings for energy-efficient fenestration: principles, products and prospects

    Author(s): Claes G. Granqvist
    Abstract: Buildings use as much as 40% of the world’s total primary energy. This huge energy consumption is mainly tied to poor designs and entrenched practices for buildings’ envelopes. One major road toward more energy efficient buildings is to employ design principles that are in harmony with the radiation in our natural surroundings. Glass coatings with spectral selectivity can lead to windows and glass facades with good thermal insulation and capability to transmit mainly visible light or, alternatively, across the full solar spectrum. Chromogenic glazings, especially if based on electrochromism, can regulate the inflow of visible light and solar energy between widely separated limits and achieve further energy efficiency. The new fenestration technologies are able to improve indoor comfort.
    How to cite …
    1. C.G. Granqvist, "Optical coatings for energy-efficient fenestration: principles, products and prospects", Advanced Optical Technologies, Vol. 3, 2014. http://dx.doi.org/10.1515/aot-2013-0042
Lighting & Illumination Archive »
  • A novel approach for extending autocollimator calibration from plane to spatial angles

    Author(s): Ralf D. Geckeler, Oliver Kranz, Andreas Just, Michael Krause
    Abstract: Autocollimators are versatile devices for the contactless measurement of the tilt angles of reflecting surfaces. In their practical application, e.g., in deflectometric profilometers for the precision form measurement of optical surfaces, the autocollimator beam is deflected in two orthogonal angular directions simultaneously. The concurrent engagement of both measuring axes results in errors in their angle response due to the crosstalk between them, which need to be calibrated. In this contribution, the capabilities of autocollimator calibration at the Physikalisch-Technische Bundesanstalt (PTB) are presented. The measurement of spatial angles is discussed in detail with a focus on achieving traceability of this measurand and reaching lowest uncertainties. A novel concept is introduced, which makes use of an innovative Cartesian arrangement of three autocollimators (two reference autocollimators and the autocollimator to be calibrated) facing a reflector cube. Each of the two reference autocollimators, which are used for the precise measurement of the cube’s angular orientation, is primarily sensitive to rotations of the cube around one of the two relevant axes and can, thus, be calibrated and traced back to PTB’s national primary standard for the plane angle in a conventional manner. In this way, the measurement of spatial angles is effectively divided into two separate measurements of plane angles. The mechanical realisation of the setup at PTB is described.
    How to cite …
    1. R.D. Geckeler, O. Kranz, A. Just, and M. Krause, "A novel approach for extending autocollimator calibration from plane to spatial angles", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0048
  • Fresnel incoherent correlation holography (FINCH): a review of research

    Author(s): Joseph Rosen, Gary Brooker
    Abstract: In this review, we describe our method for creating holograms of incoherent objects, dubbed Fresnel incoherent correlation holography (FINCH). FINCH creates holograms by a single-channel on-axis incoherent interferometer process. Like any Fresnel hologram, the object is correlated with quadratic phase functions, but the correlation is carried out without any movement. Generally, in the FINCH system, light is reflected, or emitted, from a three-dimensional (3D) object, propagates through a spatial light modulator (SLM), and is recorded by a digital camera. The SLM is used as a beam-splitter of the single-channel incoherent interferometer, such that each spherical beam originated from each object point is split into two spherical beams with two different curve radiuses. Incoherent summing of the entire interferences between all the couples of the spherical beams creates the Fresnel hologram of the observed 3D object. When this hologram is reconstructed in the computer, the 3D properties of the object are revealed. In this review, we describe various aspects of FINCH which have been described recently, including FINCH of reflected white light, FINCH of fluorescence objects, a FINCH-based holographic fluorescence microscope, a FINCH configuration which capitalizes on the polarization sensitivity of the SLM and finally FINCH is analyzed in view of linear system theory.
    How to cite …
    1. J. Rosen, and G. Brooker, "Fresnel incoherent correlation holography (FINCH): a review of research", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0014
Interferometry Archive »
  • Material and technology trends in fiber optics

    How to cite …
  • Annular beam shaping system for advanced 3D laser brazing

    Author(s): Oliver Pütsch, Jochen Stollenwerk, Markus Kogel-Hollacher, Martin Traub
    Abstract: As laser brazing benefits from advantages such as smooth joints and small heat-affected zones, it has become established as a joining technology that is widely used in the automotive industry. With the processing of complex-shaped geometries, recent developed brazing heads suffer, however, from the need for continuous reorientation of the optical system and/or limited accessibility due to lateral wire feeding. This motivates the development of a laser brazing head with coaxial wire feeding and enhanced functionality. An optical system is designed that allows to generate an annular intensity distribution in the working zone. The utilization of complex optical components avoids obscuration of the optical path by the wire feeding. The new design overcomes the disadvantages of the state-of-the-art brazing heads with lateral wire feeding and benefits from the independence of direction while processing complex geometries. To increase the robustness of the brazing process, the beam path also includes a seam tracking system, leading to a more challenging design of the whole optical train. This paper mainly discusses the concept and the optical design of the coaxial brazing head, and also presents the results obtained with a prototype and selected application results.
    How to cite …
    1. O. Pütsch, J. Stollenwerk, M. Kogel-Hollacher, and M. Traub, "Annular beam shaping system for advanced 3D laser brazing", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0040
Optics for Material Processing Archive »
  • Bandlimited illumination with engineered diffusers

    Author(s): Tasso R.M. Sales
    Abstract: Engineered diffusers are refractive, achromatic optical elements with the capability to not only spread and homogenize an input beam but also shape the distribution of energy as well as intensity profiles. Bandlimited illumination is of particular interest for many applications that require certain intensity profiles over specific angular range with maximum efficiency. Here, we describe the concept and design of engineered diffusers as well as the method to fabricate them, from the initial resist master to volume production. Engineered diffusers are found to provide nearly ideal bandlimited illumination without image artifacts and with acceptable manufacturing tolerances.
    How to cite …
    1. T.R. Sales, "Bandlimited illumination with engineered diffusers", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0012
  • Deconvolution for digital in-line holographic microscopy

    Author(s): Brenden Scott Nickerson, Hans Jürgen Kreuzer
    Abstract: To improve the resolution in point source digital in-line holography, we present two deconvolutions, one for the illumination system (coherent or partially coherent light source such as a laser or diode and pinhole) and one for the finite numerical aperture of the hologram. We show that for a system with moderate numerical aperture, optimal resolution of λ/2 laterally and λ in depth can be achieved.
    How to cite …
    1. B.S. Nickerson, and H.J. Kreuzer, "Deconvolution for digital in-line holographic microscopy", Advanced Optical Technologies, Vol. 2, 2013. http://dx.doi.org/10.1515/aot-2013-0030
Microscopy Technologies Archive »
  • Path to meter class single crystal silicon (SCSi) space optics

    Author(s): Douglas R. McCarter
    Abstract: With the global financial crisis affecting funding for space systems development, customers are calling for lower cost systems. Yet, at the same time, these lower cost systems must have increased thermal response to operational environments and load survivability. We submit that single crystal silicon (SCSi) meets both of these requirements. This paper will highlight some key SCSi material properties, discuss the opportunities that led to the development of McCarter processing methods, and present the latest steps in the manufacturing path of McCarter Mirrors using SCSi, GFB (glass frit bonding) and MSF (McCarter super finish), including the concept drawing of a one meter SCSi lightweight mirror, which together sets up the last step toward a lower cost, high performing one meter SCSi space optic.
    How to cite …
    1. D.R. McCarter, "Path to meter class single crystal silicon (SCSi) space optics", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2011-0010
  • Thermal optical path difference analysis of the telescope correct lens assembly

    Author(s): Ming-Ying Hsu, Shenq-Tsong Chang, Ting-Ming Huang
    Abstract: The effect of correct lens thermal optical path difference (OPD) on the optical performance of the Cassegrain telescope system is presented. The correct lens assembly includes several components such as a set of correct lenses, lens mount, spacer, mount barrel, and retainer. The heat transfer from the surrounding environment to the correct lens barrel will cause optical system aberration. The temperature distribution of the baffle is from 20.546°C to 21.485°C. Meanwhile, the off-axis ray’s path of the OPD has taken the lens incidence point and emergence point into consideration. The correct lens temperature distribution is calculated by the lens barrel heat transfer analysis; the thermal distortion and stress are solved by the Finite Element Method (FEM) software. The temperature distribution is weighted to each incidence ray path, and the thermal OPD is calculated. The thermal OPD on the Z direction is transferred to optical aberration by fitting OPD into a rigid body motion and the Zernike polynomial. The aberration results can be used to evaluate the thermal effect on the correct lens assembly in the telescope system.
    How to cite …
    1. M. Hsu, S. Chang, and T. Huang, "Thermal optical path difference analysis of the telescope correct lens assembly", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0058
Optomechanical Engineering Archive »
  • Path to meter class single crystal silicon (SCSi) space optics

    Author(s): Douglas R. McCarter
    Abstract: With the global financial crisis affecting funding for space systems development, customers are calling for lower cost systems. Yet, at the same time, these lower cost systems must have increased thermal response to operational environments and load survivability. We submit that single crystal silicon (SCSi) meets both of these requirements. This paper will highlight some key SCSi material properties, discuss the opportunities that led to the development of McCarter processing methods, and present the latest steps in the manufacturing path of McCarter Mirrors using SCSi, GFB (glass frit bonding) and MSF (McCarter super finish), including the concept drawing of a one meter SCSi lightweight mirror, which together sets up the last step toward a lower cost, high performing one meter SCSi space optic.
    How to cite …
    1. D.R. McCarter, "Path to meter class single crystal silicon (SCSi) space optics", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2011-0010
  • Thermal optical path difference analysis of the telescope correct lens assembly

    Author(s): Ming-Ying Hsu, Shenq-Tsong Chang, Ting-Ming Huang
    Abstract: The effect of correct lens thermal optical path difference (OPD) on the optical performance of the Cassegrain telescope system is presented. The correct lens assembly includes several components such as a set of correct lenses, lens mount, spacer, mount barrel, and retainer. The heat transfer from the surrounding environment to the correct lens barrel will cause optical system aberration. The temperature distribution of the baffle is from 20.546°C to 21.485°C. Meanwhile, the off-axis ray’s path of the OPD has taken the lens incidence point and emergence point into consideration. The correct lens temperature distribution is calculated by the lens barrel heat transfer analysis, the thermal distortion and stress are solved by the Finite Element Method (FEM) software. The temperature distribution is weighted to each incidence ray path, and the thermal OPD is calculated. The thermal OPD on the Z direction is transferred to optical aberration by fitting OPD into a rigid body motion and the Zernike polynomial. The aberration results can be used to evaluate the thermal effect on the correct lens assembly in the telescope system.
    How to cite …
    1. M. Hsu, S. Chang, and T. Huang, "Thermal optical path difference analysis of the telescope correct lens assembly", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0058
Optics for Astronomy Archive »
  • Holographic wavefront sensor for fast defocus measurement

    Author(s): Andreas Zepp, Szymon Gładysz, Karin Stein
    Abstract: Atmospheric effects significantly influence the propagation of light. Conventional adaptive optics systems, based on Shack-Hartmann sensors (SHS), work well for vertical-path propagation. However, for more challenging scenarios like horizontal-path imaging or free-space laser communications through extended-volume turbulence and strong scintillation, the bandwidth of SHS is insufficient. A promising alternative is the holographic wavefront sensor (HWFS). Our paper deals with some dependencies and limitations of the HWFS. First, we show that the sensitivity of the HWFS is highly dependent on the detector size. The smaller the detector, the more sensitive is the sensor. This has consequences in the photon-starved regime, which would naturally occur when the sensor is operated at the intended MHz speed. Second, we show that uncorrected (or residual) tip/tilt has a large impact on the accuracy of the measurement. We present experimental results of measuring an important and also easily correctable aberration, defocus, with the HWFS.
    How to cite …
    1. A. Zepp, S. Gładysz, and K. Stein, "Holographic wavefront sensor for fast defocus measurement", Advanced Optical Technologies, Vol. 2, 2013. http://dx.doi.org/10.1515/aot-2013-0050
  • Infrared detectors for space applications

    Author(s): Wolfgang Fick, Kai Uwe Gassmann, Luis-Dieter Haas, Markus Haiml, Stefan Hanna, Dominique Hübner, Holger Höhnemann, Hans-Peter Nothaft, Richard Thöt
    Abstract: The motivation and intended benefits for the use of infrared (IR) detectors for space applications are highlighted. The actual status of state-of-the-art IR detectors for space applications is presented based on some of AIM’s currently ongoing focal plane detector module developments covering the spectral range from the short-wavelength IR (SWIR) to the long-wavelength IR (LWIR) and very long-wavelength IR (VLWIR), where both imaging and spectroscopy applications will be addressed. In particular, the integrated detector cooler assemblies for a mid-wavelength IR (MWIR) push-broom imaging satellite mission, for the German hyperspectral satellite mission EnMAP and the IR detectors for the Sentinel 3 SLSTR will be elaborated. Additionally, dedicated detector modules for LWIR/VLWIR sounding, providing the possibility to have two different PVs driven by one ROIC, will be addressed.
    How to cite …
    1. W. Fick, K.U. Gassmann, L. Haas, M. Haiml, S. Hanna, D. Hübner, H. Höhnemann, H. Nothaft, and R. Thöt, "Infrared detectors for space applications", Advanced Optical Technologies, Vol. 2, 2013. http://dx.doi.org/10.1515/aot-2013-0046
Imaging Sensors & Cameras Archive »
  • Photographers are our best friends!

    Author(s): Andreas Thoss
    Abstract: Leica is one of the most famous brands among all camera manufacturers. Nevertheless, the company Leica Camera almost vanished when the digital camera technology conquered the market. Andreas Kaufmann’s company ACM took over Leica in 2004 and 2005. And against all odds, he led it to overwhelming success in the digital era. Andreas Thoss from Advanced Optical Technologies spoke with him about Leica’s remarkable comeback.
    How to cite …
    1. A. Kaufmann, "Photographers are our best friends!", Advanced Optical Technologies, Vol. 1, 2012. http://dx.doi.org/10.1515/aot-2012-0063
  • SMETHODS: Free courses on optical design

    Author(s): Andreas Thoss
    Abstract: In September 2011, a program for free education in optical design in Europe started. It is funded by the European Commission. The full title of the project is: ‘SMEs Training and Hands-on Practice in Optical Design and Simulation’. The intention of the project is to give employees of European small and medium enterprises a hands-on training from leading experts in the field of optical design. Typically, a training is held at one of the consortium’s member sites and lasts for 4 or 5 days. A full and up-to-date schedule is given at the project’s website www.smethods.eu. Already more than one hundred people have taken part in the recent activities of the project. A continuation is planned for 2014 and is currently under discussion.
    How to cite …
    1. "SMETHODS: Free courses on optical design", Advanced Optical Technologies, Vol. 2, 2013. http://dx.doi.org/10.1515/aot-2013-0026
Views & Markets Archive »
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