Dr. Shay Joseph Profile

Dr. Shay Joseph

Head of R&D at Rafael Advanced Defense Systems Ltd

SPIE Involvement:

Conference Program Committee | Author

Proceedings Article | 12 April 2021 Presentation + Paper

Thermal shock resistance test on ZnS domes

Yarden Weber, Tal Azoulay, Elaad Mograbi, Evyatar Kassis, Shay Joseph, Doron Yadlovker

Proceedings Volume 11740, 1174010 (2021) https://doi.org/10.1117/12.2581326

KEYWORDS: Domes, Resistance, Zinc, Missiles, Materials processing, Infrared materials, Chemical vapor deposition

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Proceedings Article | 15 June 2018 Paper

Optical window detachment using a 3-axis hotwire system

S. Zomerstein, Y. Weber, S. Joseph, A. Levy, D. Yadlovker, A. E. Shinman-Avraham

Proceedings Volume 10692, 1069202 (2018) https://doi.org/10.1117/12.2306122

KEYWORDS: Adhesives, Windows, Temperature metrology, Optical coatings, Optical fabrication, Thermography, Optical components, Aluminum, Carbon, Resistance

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Proceedings Article | 3 May 2017 Presentation + Paper

Scattering properties of hot isostatic pressed multispectral zinc sulfide

Marcus Trost, Nadja Felde, Sven Schröder, Shay Joseph, Arit Shienmann

Proceedings Volume 10179, 101790D (2017) https://doi.org/10.1117/12.2262552

KEYWORDS: Scattering, Light scattering, Laser scattering, Visible radiation, Zinc, Infrared imaging, Infrared radiation, Imaging systems, Optics manufacturing, Manufacturing, Surface roughness, Platinum, Sensors, Scatter measurement

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Proceedings Article | 22 May 2015 Paper

Stress analysis of optical coatings for improved durability and performance of high-end optical components

S. Joseph, A. Gleizer, D. Yadlovker, A. Shinmam

Proceedings Volume 9453, 94530R (2015) https://doi.org/10.1117/12.2176194

KEYWORDS: Optical coatings, Thin films, Optical components, Thin film coatings, Semiconducting wafers, Chemical elements, Deposition processes, Silicon, Optical design, Stress analysis

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Modern optical systems are often required to function in severe environmental conditions for prolonged periods without suffering from performance degradation. Essential parts of such electo-optical systems are windows, domes and other optical elements. These elements are almost always coated with an efficient, multispectral and highly durable antireflection coating. The complexity further increases when these coatings are applied on curved surfaces, such as hemispherical domes that are usually used in order to allow a wider field of regard. The durability of the coated optical component is dependent upon many different parameters such as deposition method and process parameters and the adhesion between layers and substrate. However, one very important parameter, which can have a significant impact on the durability and optical performance, is the stress state of the applied anti-reflection layers. This subject is mostly left untreated mainly due to the difficulty of characterization and modeling techniques and lack of thin film mechanical constants which sometimes significantly differ from the bulk constants of the same material. The stress state of the optical part is mainly determined by the mechanical properties of the coating materials and substrate, geometrical shape of the part and the thickness of the layers. In this work, both analytical and experimental approaches were used for characterization of stress distribution in thin optical films. Various single and multiple thin films were deposited using the electron beam evaporation technique onto Si 6'' wafers. The film thickness was measured using an ellipsometer and the bi-axial module of the different films was studied by measuring the change in radius of curvature of the Si substrate and applying Stoney's equation. The results were compared to the analytical Timoshenko solution of stress state in a single and multiple film structure. Knowing the stress state of a multi-layer coating would allow the engineer to design a part with the desired stress state which alongside the optical design, is expected to bring about a significant improvement in the durability and optical performance.

Proceedings Article | 4 June 2013 Paper

Challenges of developing hemispherical ZnS domes coated with a durable anti-reflection coating

S. Joseph, D. Yadlovker, E. Kassous, A. Levi, O. Marcovich, A. Shinman, H. Zipin

Proceedings Volume 8708, 87080O (2013) https://doi.org/10.1117/12.2015697

KEYWORDS: Coating, Zinc, Chemical vapor deposition, Domes, Antireflective coatings, Reflection, Computer simulations, Clouds, Visible radiation, Optical components

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Proceedings Article | 28 April 2009 Paper

Evaluating environmental survivability of optical coatings

Shay Joseph, Doron Yadlovker, Orna Marcovitch, Hedva Zipin

Proceedings Volume 7302, 73020I (2009) https://doi.org/10.1117/12.816463

KEYWORDS: Optical coatings, Short wave infrared radiation, Transmittance, Mid-IR, Silicon, Humidity, Sapphire, Optical microscopes, Zinc, Germanium

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Proceedings Article | 2 May 2007 Paper

High durability antireflection coatings for silicon and multispectral ZnS

Shay Joseph, Orna Marcovitch, Ygal Yadin, Dror Klaiman, Nitzan Koren, Hedva Zipin

Proceedings Volume 6545, 65450T (2007) https://doi.org/10.1117/12.713081

KEYWORDS: Zinc, Antireflective coatings, Oxides, Silicon, Optical coatings, Refraction, Ions, Absorption, Thin film coatings, Cladding

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In the current complex battle field, military platforms are required to operate on land, at sea and in the air in all weather conditions both day and night. In order to achieve such capabilities, advanced electro-optical systems are being constantly developed and improved. These systems such as missile seeker heads, reconnaissance and target acquisition pods and tracking, monitoring and alert systems have external optical components (window or dome) which must remain operational even at extreme environmental conditions. Depending on the intended use of the system, there are a few choices of window and dome materials. Amongst the more common materials one can point out sapphire, ZnS, germanium and silicon. Other materials such as spinel, ALON and yittria may also be considered. Most infrared materials have high indices of refraction and therefore they reflect a large part of radiation. To minimize the reflection and increase the transmission, antireflection (AR) coatings are the most common choice. Since these systems operate at different environments and weather conditions, the coatings must be made durable to withstand these extreme conditions. In cases where the window or dome is made of relatively soft materials such as multispectral ZnS, the coating may also serve as protection for the window or dome. In this work, several antireflection coatings have been designed and manufactured for silicon and multispectral ZnS. The coating materials were chosen to be either oxides or fluorides which are known to have high durability. Ellipsometry measurements were used to characterize the optical constants of the thin films. The effects of the deposition conditions on the optical constants of the deposited thin films and durability of the coatings will be discussed. The coatings were tested according to MIL-STD-810E and were also subjected to rain erosion tests at the University of Dayton Research Institute (UDRI) whirling arm apparatus in which one of the coatings showed no rain drop impact damage at all.

Proceedings Article | 18 May 2005 Paper

Improved rain erosion protection for multi-spectral ZnS

Shay Joseph, Orna Marcovitch, Ygal Yadin, Avi Steimberg, Hedva Zipin

Proceedings Volume 5786, (2005) https://doi.org/10.1117/12.603106

KEYWORDS: Coating, Zinc, Antireflective coatings, Transparency, Solids, Velocity measurements, Scanning electron microscopy, Forward looking infrared, Domes, Laser damage threshold

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Showing 5 of 8 publications

Conference Committee Involvement (4)

Optical Fabrication and Testing VIII

8 April 2024 | Strasbourg, France

Optical Fabrication, Testing, and Metrology VII

13 September 2021 | Online Only, Spain

Optical Fabrication, Testing, and Metrology VI

15 May 2018 | Frankfurt, Germany

Optical Fabrication, Testing, and Metrology V

7 September 2015 | Jena, Germany

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