Mr. Gevork S. Gevorkyan Profile

Gevork S. Gevorkyan

Experimental Research Associate at Lawrence Berkeley National Lab

SPIE Involvement:

Author

Publications (7)

Proceedings Article | 17 September 2018 Presentation + Paper

The ALS OSMS: Optical Surface Measuring System for high accuracy two-dimensional slope metrology with state-of-the-art x-ray mirrors

Ian Lacey, Kevan Anderson, Gary Centers, Ralf Geckeler, Gevork Gevorkyan, John Grossiord, Andreas Just, Theo Nicolot, Brian Smith, Valeriy Yashchuk

Proceedings Volume 10760, 1076002 (2018) https://doi.org/10.1117/12.2321347

KEYWORDS: Mirrors, Calibration, Metrology, X-ray optics, X-rays, Autocollimators, Gaussian filters, Sensors

Read Abstract +

Proceedings Article | 18 January 2018 Paper

Correlation methods in optical metrology with state-of-the-art x-ray mirrors

Valeriy Yashchuk, Gary Centers, Gevork Gevorkyan, Ian Lacey, Brian Smith

Proceedings Volume 10612, 106120O (2018) https://doi.org/10.1117/12.2305441

KEYWORDS: Mirrors, Metrology, Error analysis, X-ray optics, X-rays, Sensors, Calibration, Switching, Data acquisition, Deflectometry

Read Abstract +

The development of fully coherent free electron lasers and diffraction limited storage ring x-ray sources has brought to focus the need for higher performing x-ray optics with unprecedented tolerances for surface slope and height errors and roughness. For example, the proposed beamlines for the future upgraded Advance Light Source, ALS-U, require optical elements characterized by a residual slope error of <100 nrad (root-mean-square) and height error of <1-2 nm (peak-tovalley). These are for optics with a length of up to one meter. However, the current performance of x-ray optical fabrication and metrology generally falls short of these requirements. The major limitation comes from the lack of reliable and efficient surface metrology with required accuracy and with reasonably high measurement rate, suitable for integration into the modern deterministic surface figuring processes. The major problems of current surface metrology relate to the inherent instrumental temporal drifts, systematic errors, and/or an unacceptably high cost, as in the case of interferometry with computer-generated holograms as a reference. In this paper, we discuss the experimental methods and approaches based on correlation analysis to the acquisition and processing of metrology data developed at the ALS X-Ray Optical Laboratory (XROL). Using an example of surface topography measurements of a state-of-the-art x-ray mirror performed at the XROL, we demonstrate the efficiency of combining the developed experimental correlation methods to the advanced optimal scanning strategy (AOSS) technique. This allows a significant improvement in the accuracy and capacity of the measurements via suppression of the instrumental low frequency noise, temporal drift, and systematic error in a single measurement run. Practically speaking, implementation of the AOSS technique leads to an increase of the measurement accuracy, as well as the capacity of ex situ metrology by a factor of about four. The developed method is general and applicable to a broad spectrum of high accuracy measurements.

Proceedings Article | 19 September 2017 Presentation

X-ray optics laboratory at the ALS: current capabilities, new challenges, and tasks for further development (Conference Presentation)

Ian Lacey, Gary Centers, Gevork Gevorkyan, Sergey Nikitin, Brian Smith, Valeriy Yashchuk

Proceedings Volume 10385, 103850D (2017) https://doi.org/10.1117/12.2275565

KEYWORDS: X-ray optics, Metrology, Optical metrology, Interferometry, Microscopy, Calibration, Diffraction, Light sources, Data processing, Optical testing

Read Abstract +

Proceedings Article | 7 September 2017 Presentation + Paper

New twist in the optical schematic of surface slope measuring long trace profiler

Sergey Nikitin, Gevork Gevorkyan, Wayne McKinney, Ian Lacey, Peter Takacs, Valeriy Yashchuk

Proceedings Volume 10385, 103850I (2017) https://doi.org/10.1117/12.2274400

KEYWORDS: X-ray optics, Metrology, Interferometry, Prisms, Optical metrology, Free electron lasers, Diffraction, Synchrotrons, Coherent x-ray sources, X-ray sources

Read Abstract +

Proceedings Article | 7 September 2017 Presentation + Paper

Surface slope metrology of highly curved x-ray optics with an interferometric microscope

Gevork Gevorkyan, Gary Centers, Kateryna Polonska, Sergey Nikitin, Ian Lacey, Valeriy Yashchuk

Proceedings Volume 10385, 103850H (2017) https://doi.org/10.1117/12.2274220

KEYWORDS: X-ray optics, Interferometry, Metrology, Optical metrology, Calibration, Optics manufacturing, Data analysis, Microscopes

Read Abstract +

Proceedings Article | 7 September 2017 Presentation + Paper

Development of a high performance surface slope measuring system for two-dimensional mapping of x-ray optics

Ian Lacey, Jérôme Adam, Gary Centers, Gevork Gevorkyan, Sergey Nikitin, Brian Smith, Valeriy Yashchuk

Proceedings Volume 10385, 103850G (2017) https://doi.org/10.1117/12.2273029

KEYWORDS: Metrology, X-ray optics, Mirrors, Nano opto mechanical systems, Calibration, Synchrotron radiation, Light sources, Diffraction, Light, Interferometry

Read Abstract +

Proceedings Article | 28 March 2017 Presentation + Paper

1.5nm fabrication of test patterns for characterization of metrological systems

S. Babin, N. Bouet, S. Cabrini, G. Calafiore, R. Conley, G. Gevorkyan, K. Munechika, A. Vladár, V. Yashchuk

Proceedings Volume 10145, 1014518 (2017) https://doi.org/10.1117/12.2257624

KEYWORDS: Metrology, Imaging systems, Contrast transfer function, Software development, Scanning electron microscopy, Semiconductors, Silicon, Diffraction, Spatial frequencies, Transmission electron microscopy, Optical fabrication, Fabrication

Read Abstract +

Showing 5 of 7 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years