The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Andreas Stemmer - One of the best experts on this subject based on the ideXlab platform.
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Low voltage, highly tunable Diffraction Grating based on dielectric elastomer actuators
Proceedings of SPIE, 2007Co-Authors: Manuel Aschwanden, Andreas StemmerAbstract:We present an electrically tunable Diffraction Grating, driven by thin-film dielectric elastomer actuators. The device combines the advantages of dielectric elastomer actuators, capable of generating very large strains, with the desirable properties of Micro-Opto-Electro-Mechanical Systems (MOEMS). The soft materials based tunable Diffraction Grating achieves a continuous Grating period change of 19.2%, when a voltage of 500 V is applied. This is an improvement by a factor of 90 compared to conventional analog tunable Diffraction Gratings based on hard materials. Further device characterization yielded a tunable angular range of more than 100 mrad. Additionally, we show that in combination with a collimated white light source (e.g. white light emitting diode), the discussed tunable Diffraction Grating can be used for wavelength-adjustable luminous sources. Integrated into displays, these light sources could facilitate the first technology able to reproduce all perceivable colors.
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Polymeric, electrically tunable Diffraction Grating based on artificial muscles
Optics Letters, 2006Co-Authors: Manuel Aschwanden, Andreas StemmerAbstract:We demonstrate a low-cost, electrically tunable Diffraction Grating that is driven by a dielectric elastomer actuator. The angular tuning range of the polymer-based device is up to 118 mrad for the first diffracted order. The achievable Grating period change of 32% is an improvement by more than a factor of 150 com- pared with existing analog tunable Diffraction Gratings based on hard materials. We show that in combina- tion with a white light source, the presented Diffraction Grating can be used as a wavelength-adjustable luminous source. Such an illuminant has a potential application in inexpensive color displays that could reproduce all perceivable colors
D P Shepherd - One of the best experts on this subject based on the ideXlab platform.
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Synchronously pumped optical parametric oscillator with Diffraction-Grating tuning
Journal of Physics D: Applied Physics, 2001Co-Authors: David C. Hanna, M. V. O'connor, M. A. Watson, D P ShepherdAbstract:The operating characteristics of a synchronously pumped optical parametric oscillator, based on periodically poled lithium niobate (PPLN), with a Diffraction Grating as the tuning element, are described and compared with design expectations. Operation at average signal output power levels of up to 2.0 W has been achieved and signal/idler tuning in the range 1.466-3.663 µm has been investigated using the tilt of the Diffraction Grating, while keeping the temperature of the PPLN fixed. A detailed investigation has been made of the operating characteristics that might be influenced by the presence of pulse tilt caused by the Grating. It is shown that any adverse effects of tilt on beam quality can be small, with the main observed effect being an excess loss. An observed tendency to oscillate in higher-order transverse modes on the long-wavelength side of the tuning range is ascribed to non-collinear phase-matching. This higher-order-mode oscillation is easily prevented by the insertion of an aperture. The analysis presented here includes a Grating loss calculation and the calculation of the tuning range achievable with a Diffraction Grating. The effects of cavity-length change on oscillator performance are also examined and it is found that the Grating can give a valuable stabilizing influence by suppressing cavity-length-induced frequency-pulling effects. Extension of the use of Gratings from the picosecond to the femtosecond regime is also considered.
Raymond G. Beausoleil - One of the best experts on this subject based on the ideXlab platform.
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Reflective silicon binary Diffraction Grating for visible wavelengths
CLEO: 2011 - Laser Science to Photonic Applications, 2011Co-Authors: Zhen Peng, Andrei Faraon, David A. Fattal, Marco Fiorentino, Jingjing Li, Raymond G. BeausoleilAbstract:We introduce a new device based on sub-wavelength resonant Gratings. We built a silicon-on-oxide reflective binary Grating for visible light that mimics the functionality of a blazed Diffraction Grating in a flat geometry.
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Reflective silicon binary Diffraction Grating for visible wavelengths
Optics Letters, 2011Co-Authors: Zhen Peng, Andrei Faraon, David A. Fattal, Marco Fiorentino, Jingjing Li, Raymond G. BeausoleilAbstract:We introduce a device based on subwavelength resonant Grating technology. Using a single lithography step we built a reflective binary Grating that mimics the functionality of a blazed Diffraction Grating in a flat geometry. We have also demonstrated that efficient subwavelength resonant devices for visible wavelengths can be built using silicon.
Manuel Aschwanden - One of the best experts on this subject based on the ideXlab platform.
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Low voltage, highly tunable Diffraction Grating based on dielectric elastomer actuators
Proceedings of SPIE, 2007Co-Authors: Manuel Aschwanden, Andreas StemmerAbstract:We present an electrically tunable Diffraction Grating, driven by thin-film dielectric elastomer actuators. The device combines the advantages of dielectric elastomer actuators, capable of generating very large strains, with the desirable properties of Micro-Opto-Electro-Mechanical Systems (MOEMS). The soft materials based tunable Diffraction Grating achieves a continuous Grating period change of 19.2%, when a voltage of 500 V is applied. This is an improvement by a factor of 90 compared to conventional analog tunable Diffraction Gratings based on hard materials. Further device characterization yielded a tunable angular range of more than 100 mrad. Additionally, we show that in combination with a collimated white light source (e.g. white light emitting diode), the discussed tunable Diffraction Grating can be used for wavelength-adjustable luminous sources. Integrated into displays, these light sources could facilitate the first technology able to reproduce all perceivable colors.
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Polymeric, electrically tunable Diffraction Grating based on artificial muscles
Optics Letters, 2006Co-Authors: Manuel Aschwanden, Andreas StemmerAbstract:We demonstrate a low-cost, electrically tunable Diffraction Grating that is driven by a dielectric elastomer actuator. The angular tuning range of the polymer-based device is up to 118 mrad for the first diffracted order. The achievable Grating period change of 32% is an improvement by more than a factor of 150 com- pared with existing analog tunable Diffraction Gratings based on hard materials. We show that in combina- tion with a white light source, the presented Diffraction Grating can be used as a wavelength-adjustable luminous source. Such an illuminant has a potential application in inexpensive color displays that could reproduce all perceivable colors
David C. Hanna - One of the best experts on this subject based on the ideXlab platform.
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Synchronously pumped optical parametric oscillator with Diffraction-Grating tuning
Journal of Physics D: Applied Physics, 2001Co-Authors: David C. Hanna, M. V. O'connor, M. A. Watson, D P ShepherdAbstract:The operating characteristics of a synchronously pumped optical parametric oscillator, based on periodically poled lithium niobate (PPLN), with a Diffraction Grating as the tuning element, are described and compared with design expectations. Operation at average signal output power levels of up to 2.0 W has been achieved and signal/idler tuning in the range 1.466-3.663 µm has been investigated using the tilt of the Diffraction Grating, while keeping the temperature of the PPLN fixed. A detailed investigation has been made of the operating characteristics that might be influenced by the presence of pulse tilt caused by the Grating. It is shown that any adverse effects of tilt on beam quality can be small, with the main observed effect being an excess loss. An observed tendency to oscillate in higher-order transverse modes on the long-wavelength side of the tuning range is ascribed to non-collinear phase-matching. This higher-order-mode oscillation is easily prevented by the insertion of an aperture. The analysis presented here includes a Grating loss calculation and the calculation of the tuning range achievable with a Diffraction Grating. The effects of cavity-length change on oscillator performance are also examined and it is found that the Grating can give a valuable stabilizing influence by suppressing cavity-length-induced frequency-pulling effects. Extension of the use of Gratings from the picosecond to the femtosecond regime is also considered.