Prof. Tigran Galstian Profile

Prof. Tigran Galstian

Professor at Univ Laval

SPIE Involvement:

Conference Program Committee | Author

Publications (73)

Proceedings Article | 29 September 2023 Presentation

Dynamic LED beam shaping by using liquid crystals

Tigran Galstian, Armen Zohrabyan, Vladimir Presniakov, Aram Bagramyan

Proceedings Volume PC12658, PC126580B (2023) https://doi.org/10.1117/12.2676798

KEYWORDS: Liquid crystals, Light emitting diodes, Beam shaping, Optical components, Light sources and illumination, Lenses, Industry, Collimation, Beam diameter

Read Abstract +

Proceedings Article | 3 October 2022 Presentation

Can we control the trans-membrane ion exchange by using amphiphilic azobenzene molecules (Conference Presentation)

Tigran Galstian, Ilham Touati, Yue Zhao

Proceedings Volume PC12212, PC1221206 (2022) https://doi.org/10.1117/12.2635898

KEYWORDS: Molecules, Ion exchange, Visible radiation, Ultraviolet radiation, Molecular biology

Read Abstract +

Proceedings Article | 3 October 2022 Presentation

A universal liquid crystal element for focusing, steering and more (Conference Presentation)

Tigran Galstian, Zhanna Zemska, Justin Stevens

Proceedings Volume PC12207, PC122070D (2022) https://doi.org/10.1117/12.2635897

KEYWORDS: Liquid crystals, Wavefronts, Prisms, Optics manufacturing, Optical components, High volume manufacturing, Axicons

Read Abstract +

Proceedings Article | 5 March 2022 Presentation

All-fiber, dynamically tunable, polarization filter based on liquid crystal filled nano-channels

Abdullah Rahnama, Tigran Dadalyan, Keivan Mahmoud Aghdami, Tigran Galstian, Peter Herman

Proceedings Volume PC12012, PC120120K (2022) https://doi.org/10.1117/12.2609196

KEYWORDS: Polarization, Wave plates, Liquid crystals, Capillaries, Waveguides, Wave propagation, Visible radiation, Thermal optics, Thermal effects, Telecommunications

Read Abstract +

Proceedings Article | 1 August 2021 Presentation

Investigating the role of the “mechanical” deformation of Azobenzene molecules for biological control

Ismael Duchesne, Tigran Galstian, Filippo Fabbri, Luca Sorelli, Denis Rodrigue, Mario Fafard

Proceedings Volume 11812, 118120A (2021) https://doi.org/10.1117/12.2595624

KEYWORDS: Molecules, Molecular biology, Toxicity, Photodynamic therapy, Biomedical optics, Bacteria

Read Abstract +

Proceedings Article | 1 August 2021 Presentation

Control of bacteria movement by using photo responsive media

Tigran Galstian, Ismael Duchesne

Proceedings Volume 11807, 118070Q (2021) https://doi.org/10.1117/12.2595634

KEYWORDS: Bacteria, Motion controllers, Liquid crystals, Ultraviolet radiation, Molecules, Magnetism, Liquids, Lab on a chip, Crystals

Read Abstract +

Proceedings Article | 22 August 2020 Presentation

Photo responsive azobenzene molecules for biological control

Tigran Galstian, Ilham Touati, Ismaël Duchesne, Yue Zhao

Proceedings Volume 11477, 114770A (2020) https://doi.org/10.1117/12.2569347

KEYWORDS: Molecules, Molecular biology, Biomedical optics

Read Abstract +

Proceedings Article | 20 August 2020 Presentation

Light scattering by liquid crystals and its impact on adaptive imaging

Tigran Galstian, Anastasiia Pusenkova

Proceedings Volume 11472, 114720X (2020) https://doi.org/10.1117/12.2569349

KEYWORDS: Liquid crystals, Light scattering, Image quality, Lenses, Cameras, Deconvolution, Scattering

Read Abstract +

Proceedings Article | 13 March 2019 Presentation

Adaptive optics using liquid-crystal lens with segmented peripheral electrode (Conference Presentation)

Tigran Galstian

Proceedings Volume 10941, 109410P (2019) https://doi.org/10.1117/12.2515714

KEYWORDS: Electrodes, Liquid crystals, Adaptive optics, Image segmentation, LCDs, Wavefronts, Optical imaging, Imaging systems, Cell phones, Cameras

Read Abstract +

Proceedings Article | 4 March 2019 Presentation

Motion free micro-endoscopic system for imaging in freely behaving animals at variable focal depths using liquid crystal lenses (Conference Presentation)

Arutyun Bagramyan, Tigran Galstian, Armen Saghatelyan

Proceedings Volume 10883, 1088313 (2019) https://doi.org/10.1117/12.2508929

KEYWORDS: Imaging systems, Liquid crystals, Lenses, GRIN lenses, Lens design, Neuroimaging, Brain, Optical simulations, Zemax, Image resolution

Read Abstract +

MICRO-ENDOSCOPE : The novel micro-endoscopic system we present was designed and simulated using Zemax optical software in order to predict some key imaging parameters such as the magnification, the field of view, the resolution, the focal shift, etc. Classical epi-fluorescence (reflected light illumination) imaging configuration was considered. SolidWorks engineering software was used for the mechanical approach/simulations. The mechanical parts of the micro-endoscope were mainly printed using a 3D laser printer (hard plastic) at the theoretical resolution of 25µm or directly fabricated and assembled in the mechanical atelier. TUNEABLE LIQUID CRYSTAL LENSES : We used an optimized modal lens approach to design polarization-insensitive optical probe that requires relatively low driving voltages to perform endoscopic depth imaging. For a single LC lens a thin weakly conductive layer of ZnO film sheet resistance was cast over the hole-patterned electrode to form a the control layer used to generate a gradually varying electric field profile along the z-axis that was applied to the NLC layer. Two perpendicularly oriented double-layer NLC “half” lenses were required to form a custom four-layers design of the TLCL (tuneable liquid crystal lens). GRIN PROBE : To enable depth imaging our 4 layer TLCL was optically coupled to the imaging probe composed of 2 different GRIN lenses : imaging GRIN lens (high NA) and a coupling GRIN lens (low NA) which were glued together using index matched optical adhesive. RESULTS : Combination of the TLCL and the GRIN probe enabled a focal shift of approximately 90 ± 3µm while maintaining a constant magnification and a lateral resolution of ≈ 1µm. The potential of our system to visualise and differentiate small neuronal structures at variable focal depth was tested by imaging neurons, dendrites and also spines in thick brain sections and also in a free behaving mouse (Flex-GFP), in deep regions of the brain such as subventricular zone (SVZ) and rostral migratory stream (RMS).

Proceedings Article | 18 September 2018 Presentation

Challenges and solutions in the increase of the liquid crystal GRIN lens diameter (Conference Presentation)

Tigran Galstian

Proceedings Volume 10735, 107350G (2018) https://doi.org/10.1117/12.2323261

KEYWORDS: GRIN lenses, Liquid crystals, LCDs, Modulators, Augmented reality, Electrodes

Read Abstract +

Proceedings Article | 14 March 2018 Presentation

Adaptive micro endoscopy using liquid crystal lenses with segmented electrodes (Conference Presentation)

Tigran Galstian, Louis Bégel, Harutyun Bagramyan

Proceedings Volume 10502, 1050202 (2018) https://doi.org/10.1117/12.2286215

KEYWORDS: Liquid crystals, Lenses, Adaptive optics, Image segmentation, Electrodes, Electro optics, Brain, Monochromatic aberrations, Wavefronts, Physics

Read Abstract +

Proceedings Article | 19 September 2017 Presentation

Intra-ocular accommodative implant using liquid crystal lenses (Conference Presentation)

Tigran Galstian

Proceedings Volume 10361, 1036111 (2017) https://doi.org/10.1117/12.2275546

KEYWORDS: Liquid crystals, Lenses, Electro optics, Adaptive optics, LCDs, Liquids, Crystals

Read Abstract +

Proceedings Article | 29 August 2017 Presentation + Paper

Smart lighting using a liquid crystal modulator

Alexandre Baril, Simon Thibault, Tigran Galstian

Proceedings Volume 10375, 103750O (2017) https://doi.org/10.1117/12.2276205

KEYWORDS: Light sources and illumination, Modulators, Liquid crystals, LED lighting, Light emitting diodes, Lens design, Machine vision, Computer vision technology, Algorithm development, Biomedical optics

Read Abstract +

Proceedings Article | 26 April 2016 Presentation

Fiber-based tissue identification for electrode placement in deep brain stimulation neurosurgery (Conference Presentation)

Damon DePaoli, Nicolas Lapointe, Laurent Goetz, Martin Parent, Michel Prudhomme, Léo Cantin, Tigran Galstian, Younès Messaddeq, Daniel Côté

Proceedings Volume 9690, 96900G (2016) https://doi.org/10.1117/12.2213353

KEYWORDS: Electrodes, Brain stimulation, Tissues, Brain, In vitro testing, Optical design, Optical fibers, Biosensing, Tissue optics, Blood vessels

Read Abstract +

Proceedings Article | 5 October 2015 Presentation

Revealing pathologies in the liquid crystalline structures of the brain by polarimetric studies (Presentation Recording)

Karen Bakhshetyan, Gurgen Melkonyan, Tigran Galstian, Armen Saghatelyan

Proceedings Volume 9565, 956511 (2015) https://doi.org/10.1117/12.2187503

KEYWORDS: Brain, Liquid crystals, Pathology, Liquids, Crystals, Crystallography, Polarimetry, Neuroimaging, Brain mapping, Tissues

Read Abstract +

Proceedings Article | 5 October 2015 Presentation

Imaging in natural light with nematic liquid crystals (Presentation Recording)

Tigran Galstian

Proceedings Volume 9565, 95650O (2015) https://doi.org/10.1117/12.2187271

KEYWORDS: Liquid crystals, Polarization, Optical components, Mirrors, LCDs, Modulators, Lenses, Refractive index, Modulation, Anisotropy

Read Abstract +

SPIE Journal Paper | 5 February 2015 Open Access

Focusing unpolarized light with a single-nematic liquid crystal layer

Tigran Galstian, Karen Allahverdyan

OE, Vol. 54, Issue 02, 025104, (February 2015) https://doi.org/10.1117/12.10.1117/1.OE.54.2.025104

KEYWORDS: Polarization, Liquid crystals, Mirrors, Wave plates, Wavefronts, Refractive index, Cameras, Chemical elements, Optical components, Reflection

Read Abstract +

DOWNLOAD PAPER

Proceedings Article | 15 December 2014 Paper

In the search of anisotropic biocompatible liquid environments for bacterial motility studies

Ismael Duchesne, Tigran Galstian, Simon Rainville

Proceedings Volume 9182, 91820M (2014) https://doi.org/10.1117/12.2063757

KEYWORDS: Bacteria, Liquid crystals, Coating, Molecules, Liquids, Microorganisms, Polarizers, Birefringence, Sodium, Microscopes

Read Abstract +

Proceedings Article | 25 September 2014 Paper

Photoinduced GRIN lens formation in chalcogenide Ge-As-S thin films

K. Palanjyan, R. Vallée, T. Galstian

Proceedings Volume 9288, 92880L (2014) https://doi.org/10.1117/12.2075129

KEYWORDS: GRIN lenses, Polarization, Glasses, Thin films, Wavefronts, Crystals, Sensors, Refractive index, Chalcogenide glass, Birefringence

Read Abstract +

Proceedings Article | 25 September 2014 Paper

Band gap dependence upon thickness of chalcogenide Ge-As-S thin films

K. Palanjyan, R. Vallée, T. Galstian

Proceedings Volume 9288, 92880K (2014) https://doi.org/10.1117/12.2075126

KEYWORDS: Thin films, Glasses, Absorption, Annealing, Chalcogenides, Germanium, Chalcogenide glass, Physics, Semiconductors, Protactinium

Read Abstract +

Proceedings Article | 25 September 2014 Paper

Study of photo isomerization and photoinduced anisotropy of a mesogenic azobenzen dye mixture in various solid and liquid matrices

A. Minasyan, A. Tork, T. Galstian

Proceedings Volume 9288, 92880N (2014) https://doi.org/10.1117/12.2075208

KEYWORDS: Absorption, Polarization, Anisotropy, Molecules, Light emitting diodes, Matrices, Laser beam diagnostics, Argon ion lasers, Liquid crystals, Solids

Read Abstract +

Proceedings Article | 27 August 2014 Paper

Nanocrystalline cellulose for optical encryption

Yu Ping Zhang, Karen Allahverdyan, Timothy Morse, Vamsy Chodavarapu, Andrew Kirk, Tigran Galstian, Mark Andrews

Proceedings Volume 9172, 91720R (2014) https://doi.org/10.1117/12.2062974

KEYWORDS: Reflection, Diffraction gratings, Ultraviolet radiation, Reflectivity, Molecules, Luminescence, Solids, Adhesives, Polarization, Polymer thin films

Read Abstract +

Proceedings Article | 2 February 2011 Paper

Tuning liquid crystal properties at hybrid glass interfaces with polarized self-inscribing guided waves

Mark Andrews, Timothy Gonzalez, Tigran Galstian

Proceedings Volume 7955, 79550I (2011) https://doi.org/10.1117/12.881490

KEYWORDS: Glasses, Liquid crystals, Waveguides, Polarization, Anisotropy, Interfaces, Optical alignment, Polymers, Birefringence, Silica

Read Abstract +

Proceedings Article | 13 May 2010 Paper

Light induced gradient polymer stabilized liquid crystals for electrically variable focus lenses: the role of network morphology

L. Zohrabyan, A.-M. Albu, A. Zohrabyan, T. Galstian

Proceedings Volume 7716, 77160D (2010) https://doi.org/10.1117/12.859079

KEYWORDS: Polymers, Light scattering, Scattering, Electro optics, Lenses, Liquid crystals, Polarizers, Electro optic polymers, Refractive index, Anisotropy

Read Abstract +

Proceedings Article | 12 August 2008 Paper

Dynamic compensation of chromatic and polarization mode dispersion using liquid crystals

R. Birabassov, A. Zohrabyan, D. Dumont, A. Tork, T. Galstian

Proceedings Volume 7099, 709912 (2008) https://doi.org/10.1117/12.805389

KEYWORDS: Polarization, Liquid crystals, Refractive index, Refraction, Dispersion, Fiber Bragg gratings, Cladding, Waveguides, Electro optics, Composites

Read Abstract +

Proceedings Article | 12 August 2008 Paper

Development of fiber long period gratings for biological sensor applications

Olivier L'Hénaf, Armen Zohrabyan, Tigran Galstian

Proceedings Volume 7099, 70990P (2008) https://doi.org/10.1117/12.805390

KEYWORDS: Cladding, Sensors, Signal attenuation, Fiber couplers, Refractive index, Fiber Bragg gratings, Ultraviolet radiation, Tunable lasers, Fiber lasers, Fiber optics sensors

Read Abstract +

Proceedings Article | 4 April 2005 Paper

In-fiber variable optical attenuation with ultra-low electrical power consumption

Armen Zohrabyan, Dany Dumont, Amir Tork, Rouslan Birabassov, Tigran Galstian

Proceedings Volume 5724, (2005) https://doi.org/10.1117/12.591280

KEYWORDS: Signal attenuation, Refractive index, Cladding, Liquid crystals, Polarization, Modulation, Waveguides, Electro optics, Free space optics, Free space

Read Abstract +

Proceedings Article | 23 March 2005 Paper

Tunable femtosecond soliton generation in a Ge-doped fiber

Daoping Wei, Tigran Galstian, Armen Zohrabyan, Levon Mouradian

Proceedings Volume 5710, (2005) https://doi.org/10.1117/12.588350

KEYWORDS: Solitons, Femtosecond phenomena, Single mode fibers, Fiber lasers, Phase modulation, Optical switching, Optical fibers, Nonlinear optics, Wavelength tuning, Polarization

Read Abstract +

Proceedings Article | 20 December 2004 Paper

Strong relief grating fabrication in amorphous chalcogenide glasses by light polarization modulation

Karen Asatryan, Tigran Galstian, Real Vallee

Proceedings Volume 5577, (2004) https://doi.org/10.1117/12.567087

KEYWORDS: Polarization, Modulation, Chalcogenide glass, Optical components, Chalcogenides, Glasses, Heat treatments

Read Abstract +

Proceedings Article | 20 December 2004 Paper

Polymer-stabilized liquid crystal lens for electro-optical zoom

Vladimir Presnyakov, Tigran Galstian

Proceedings Volume 5577, (2004) https://doi.org/10.1117/12.567483

KEYWORDS: Liquid crystals, Polymers, Zoom lenses, Laser beam diagnostics, Electro optics, Electro optic polymers, Refractive index, CCD cameras, Ultraviolet radiation, Cameras

Read Abstract +

Proceedings Article | 20 December 2004 Paper

Low-loss and low-polarization-dependent fiber variable optical attenuators

Tigran Galstian, Armen Zohrabyan, Amir Tork, Rouslan Birabassov, Richard Jewell, Dany Dumont, Bertrand Gagnon

Proceedings Volume 5577, (2004) https://doi.org/10.1117/12.567249

KEYWORDS: Signal attenuation, Cladding, Control systems, Electronics, Waveguides, Electrodes, Birefringence, Photonic integrated circuits, Polarization, Polymers

Read Abstract +

Proceedings Article | 15 December 2003 Paper

Spectral properties of the IR-140 dye in liquid crystal matrices

Vladimir Presnyakov, Tigran Galstian

Proceedings Volume 5260, (2003) https://doi.org/10.1117/12.543536

KEYWORDS: Liquid crystals, Absorption, Matrices, Polymers, Absorbance, Near infrared, Photopolymerization, Crystals, Photonic crystals, Liquids

Read Abstract +

Proceedings Article | 15 December 2003 Paper

Liquid crystal-filled nuclear pore membranes for photonic applications

Isabelle Chabot, Vladimir Presnyakov, Tigran Galstian, Emile Knystautas

Proceedings Volume 5260, (2003) https://doi.org/10.1117/12.543531

KEYWORDS: Liquid crystals, Ions, Polymers, Etching, Light scattering, Photonic crystals, Refractive index, Scattering, Neon, Polymer thin films

Read Abstract +