Mr. Vic Hejmadi Profile

Vic Hejmadi

President/Chief Executive Officer at USI Photonics Inc

SPIE Involvement:

Author

Proceedings Article | 10 May 2012 Paper

Structured IR illumination for relative depth sensing in virtual interfaces

Bernard Kress, Victorien Raulot, Michel Grossman

Proceedings Volume 8368, 83680K (2012) https://doi.org/10.1117/12.919645

KEYWORDS: Sensors, Infrared sensors, Interfaces, Projection systems, Infrared cameras, Objectives, CMOS sensors, Diffraction, Infrared imaging, Signal processing

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Proceedings Article | 26 May 2011 Paper

Speckle reduction technique for laser based automotive Head Up Display (HUD) projectors

Bernard Kress, Vic Hejmadi

Proceedings Volume 8026, 80260P (2011) https://doi.org/10.1117/12.886536

KEYWORDS: Speckle, Liquid crystal on silicon, Heads up displays, Speckle pattern, Projection systems, Reconstruction algorithms, Computer generated holography, Eye, Diffraction, Polarization

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Proceedings Article | 21 April 2011 Paper

Novel solar cogeneration trough system based on stretched microstructured mylar film

Vic Hejmadi, Meimei Shin, Bernard Kress, Alfredo Giliberto

Proceedings Volume 8065, 80650G (2011) https://doi.org/10.1117/12.896197

KEYWORDS: Solar cells, Visible radiation, Reflectivity, Sun, Diffraction, Photovoltaics, Infrared radiation, Silicon, Space telescopes, Modulation

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Hybrid CSP / CPV (Concentrating Solar Power / Concentration Photovoltaic) systems provide a good alternative to traditional CPV systems or CSP trough architectures. Such systems are often described as solar cogeneration systems. Trough systems use mainly the IR portion of the spectrum in order to heat up a pipe in which water is circulating. CPV systems use only the visible portion of the spectrum to produce the photo-voltaic conversion. Due to the achromatic nature of traditional thermal trough CSP systems, it is very unlikely that a CPV system can be integrated with a CSP system, even a low concentration CPV system (LCPV). We propose a novel technique to implement a low concentration CSP/LCPV system which relies on commercially available solar trough concentrators / trackers that use reflective stretched Mylar membranes. However, here the Mylar is embossed with microstructures that act only on the visible portion of the spectrum, leaving the infrared part of the solar spectrum unperturbed. This architecture has many advantages, such as: the existing Mylar-based thermal trough architecture is left unperturbed for optimal thermal conversion, with linear strips of PV cells located a few inches away from the central water pipe; the infrared radiation is focused on the central pipe, away from the PV cells, which remain relatively cool compared to conventional LCPV designs (only visible light (the PV convertible part of the solar spectrum) is diffracted onto the PV cell strips); and the Mylar sheets can be embossed by conventional roll-to-roll processes, with a one-dimensional symmetric micro-structured pattern. We show how the positive master elements are designed and fabricated over a small area (using traditional IC wafer fabrication techniques), and how the Mylar sheets are embossed by a recombined negative nickel shim. We also show that such a system can efficiently filter the visible spectrum and divert it onto the linear strips of PV cells, while leaving the infrared part of the spectrum un-perturbed, heating up the water pipe.

Proceedings Article | 13 May 2010 Paper

Digital diffractive optics: Have diffractive optics entered mainstream industry yet?

Bernard Kress, Vic Hejmadi

Proceedings Volume 7716, 77161J (2010) https://doi.org/10.1117/12.859086

KEYWORDS: Optical signal processing, Digital electronics, Optical components, Computer aided design, Diffraction, Wafer-level optics, Fabrication, Analog electronics, Free space optics, Ray tracing

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Proceedings Article | 21 April 2010 Paper

Virtual optical interfaces for the transportation industry

Vic Hejmadi, Bernard Kress

Proceedings Volume 7675, 76750C (2010) https://doi.org/10.1117/12.851990

KEYWORDS: Interfaces, Projection systems, Sensors, CMOS sensors, Semiconductor lasers, Optical components, Image processing, Diffraction, Semiconducting wafers, Objectives

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Proceedings Article | 6 May 2009 Paper

Distributed network of integrated 3D sensors for transportation security applications

Vic Hejmadi, Fred Garcia

Proceedings Volume 7314, 73140B (2009) https://doi.org/10.1117/12.821381

KEYWORDS: Sensors, Cameras, Projection systems, CMOS sensors, Fringe analysis, Video, Objectives, Imaging systems, Digital signal processing, Video surveillance

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Showing 5 of 6 publications

Conference Committee Involvement (2)

Photonics in the Transportation Industry: Auto to Aerospace III

5 April 2010 | Orlando, Florida, United States

Photonics in the Transportation Industry: Auto to Aerospace II

13 April 2009 | Orlando, Florida, United States

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