Nelson Tabirian

Dr. Nelson Tabirian


Research Focus & Metrics

Academic Career Length

33Years (1994-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 December 2009 in Soft Matter
Verified
Journal Article
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SSSvetlana Serak
Svetlana Serak
NTNelson Tabirian
Nelson Tabirian
RVRafael Vergara
Rafael Vergara
TWTimothy J. White
Timothy J. White
RVRichard A. Vaia
Richard A. Vaia
TBTimothy J. Bunning
Timothy J. Bunning
We report on the laser and sunlight driven, fast and large oscillation of cantilevers composed of photoresponsive liquid crystal polymer materials. The oscillation frequency, driven with a focused 100 mW laser of multiple wavelengths (457, 488, 514 nm), is as high as 270 Hz and is shown to be strongly correlated to the physical dimensions of the cantilever. The experimental frequency response is accurately described by the calculated natural resonant frequency for a non-damped cantilever. To further understand the conversion efficiency of light energy to mechanical work in the system, the oscillatory behavior of a 2.7 mm × 0.7 mm × 0.04 mm cantilever was examined at pressures ranging from 1 atm to 0.03 atm. A large increase in amplitude from 110° at STP to 250° at low pressure was observed. A first approximation of the system efficiency was calculated at 0.1%. The large increase in amplitude at low pressure indicates strong hydrodynamic loss and thus, the material efficiency is potentially much greater. Using a simple optical setup, oscillatory behavior was also demonstrated using sunlight. This work indicates the potential for remotely triggered photoactuation of photoresponsive polymer cantilevers from long distances with lasers or focused sunlight.

29 June 2007 in Advanced Functional Materials
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Journal Article
Closed access
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UHU. A. Hrozhyk
U. A. Hrozhyk
SSS. V. Serak
S. V. Serak
NTNelson Tabirian
Nelson Tabirian
TBT. J. Bunning
T. J. Bunning

25 September 2007 in Advanced Materials
Verified
Journal Article
Closed access
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UHU. A. Hrozhyk
U. A. Hrozhyk
SSS. V. Serak
S. V. Serak
NTNelson Tabirian
Nelson Tabirian
TBT. J. Bunning
T. J. Bunning

16 September 2009 in Optics Express
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Journal Article
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SXSu Xu
Su Xu
HRHongwen Ren
Hongwen Ren
YLYeong-Jyh Lin
Yeong-Jyh Lin
MMM. G. Jim Moharam
M. G. Jim Moharam
SWShin-Tson Wu
Shin-Tson Wu
NTNelson Tabirian
Nelson Tabirian
An adaptive liquid lens actuated by a photo-polymer is demonstrated. The lens cell consists of a top glass substrate and a bottom plastic slab with two holes: reservoir hole and lens hole, which are sealed with elastic membranes. A photo-sensitive polymer is attached to the membrane of the reservoir hole. Under blue light irradiation, the polymer is bent which exerts a pressure to regulate the curvature of the membrane on the lens hole and then change the focal length of the plano-convex lens. The focal length is tunable from infinity to 21.2 mm in seconds. Non-mechanical driving, easy integration with other optical components and compact system are the key features of this lens.

22 September 2015 in Optics Express
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Journal Article
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NTNelson Tabirian
Nelson Tabirian
SSSvetlana V. Serak
Svetlana V. Serak
DRDavid E. Roberts
David E. Roberts
DSDiane M. Steeves
Diane M. Steeves
BKBrian R. Kimball
Brian R. Kimball
We present new lenses – waveplate lenses created in liquid crystal and liquid crystal polymer materials. Using an electrically-switchable liquid-crystal half-wave retarder we realized switching between focused and defocused beams by the waveplate lens. A combination of two such lenses allowed the collimation of a laser beam as well as the change of focal length of optical system.

28 March 2013 in Optics Express
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Journal Article
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SNSarik R. Nersisyan
Sarik R. Nersisyan
NTNelson Tabirian
Nelson Tabirian
DMDimitri Mawet
Dimitri Mawet
ESEugene Serabyn
Eugene Serabyn
Vector vortex waveplates (VVWs) open the door to new techniques in stellar coronagraphy and optical communications, but the performance of currently available liquid-crystal-polymer-based VVWs tends to be limited by defects in the axial region of the vortex pattern. As described here, several steps allow for a reduction in the size of such axial defects, including the use of photoalignment materials with high photosensitivity and reversible response, and a reduction in exposure energy. Moreover, redistributing the writing beam’s intensity from the axial region to its periphery (using a VVW) allows the production of large area VVWs with a small defect area. Finally, using VVWs as linear to axial polarization converters allows producing VVWs of higher topological charge, while also reducing the photoalignment time to a few minutes. These steps have allowed the fabrication of VVWs with topological charges of 1 and 2 with central defect sizes below 3 μm.