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Open-loop shape control for continuous microelectromechanical system deformable mirror
Alioune Diouf, Andrew P. Legendre, Jason B. Stewart, Thomas G. Bifano, Yang Lu
We characterize the errors associated with open-loop control of a microelectromechanical system deformable mirror (DM) using an approach that combines sparse calibration of the electrostatic actuator state space with an elastic plate model of the mirror facesheet. We quantify sources of measurement ... [Appl. Opt. 49, G148-G154 (2010)]
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System optimization of a long-range Brillouin-loss-based distributed fiber sensor
Yongkang Dong, Liang Chen, Xiaoyi Bao
We report a high-performance 25km Brillouin-loss-based distributed fiber sensor through optimizing system parameters. First, the Brillouin spectrum distortion and measurement error induced by the excess amplification on probe pulse are investigated, and the results indicate that a low ... [Appl. Opt. 49, 5020-5025 (2010)]
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Simple two-layer reflectance model for biological tissue applications: lower absorbing layer
George Zonios, Aikaterini Dimou
A simple two-layer tissue reflectance model is described. This work is a continuation of our investigations on modeling reflectance from two-layered tissues that we recently initiated. In the present article, we describe a variation of a two-layer model that assumes a lower absorbing and scattering ... [Appl. Opt. 49, 5026-5031 (2010)]
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Orientation-free pressure sensor based on ?-shifted single-mode-fiber Sagnac interferometer
Jiulin Gan, Li Shen, Qing Ye, Zhengqing Pan, Haiwen Cai, Ronghui Qu
We propose and analyze a novel orientation-free pressure sensor based on a ?-shifted all-single-mode-fiber (SMF) Sagnac interferometer. Compared with a conventional pressure sensor based on high-birefringence polarization-maintaining fiber, this all-SMF structure is more simple, stable, and ... [Appl. Opt. 49, 5043-5048 (2010)]
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Resolution improvement in digital holography by angular and polarization multiplexing
Caojin Yuan, Guohai Situ, Giancarlo Pedrini, Jun Ma, Wolfgang Osten
Angular and polarization multiplexing techniques are utilized in both object and reference arms in the digital holographic microscopy system to improve its resolution. The angular multiplexing provides on-axis and off-axis illumination and reference beams with different carrier frequencies. ... [Appl. Opt. 50, B6-B11 (2011)]
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Rapid fabrication of an electrically switchable liquid crystal Fresnel zone lens
Yimin Lou, Qingkun Liu, Hui Wang, Yaocheng Shi, Sailing He
Based on a nanoimprint technique, a new method is proposed for the rapid fabrication of an electrically switchable liquid crystal Fresnel zone lens (SLCFZL). The flow chart of the proposed fabrication method for a SLCFZL is given and a binary SLCFZL is experimentally demonstrated using the proposed ... [Appl. Opt. 49, 4995-5000 (2010)]
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Circular multireflection cell for optical spectroscopy
Johannes Ofner, Heinz-Ulrich Kr?, Cornelius Zetzsch
We constructed a circular multireflection (CMR) cell, allowing multireflection around the center of the cell. This is caused by a skewed adjustment of the entering beam (equivalent to a simple parallel shift/offset), avoiding the center of the cell, thus leading to multiple reflections. The ... [Appl. Opt. 49, 5001-5004 (2010)]
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Pattern effect reduction in all-optical wavelength conversion using a two-electrode semiconductor optical amplifier
Peng Tian, Lirong Huang, Wei Hong, Dexiu Huang
A two-electrode semiconductor optical amplifier that has two sections and two separated electrodes is proposed for an all-optical wavelength converter. Pattern effect reduction based on dynamic gain compensation is theoretically investigated using a time-domain model that takes into account the ... [Appl. Opt. 49, 5005-5012 (2010)]
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Enhancement of magneto-optical effects in magnetic nanoparticles near gold-dielectric surfaces
Vasyl G. Kravets, Anatoliy S. Lapchuk
We report enhanced magneto-optical Kerr rotation in the layer systems of a magnetic granular film coated by uniform gold and dielectric films. The Kerr rotation spectra measured from 1.2 to 5eV show a peak at about 2.7eV, not present in either uncoated magnetic particle films. It was shown that the ... [Appl. Opt. 49, 5013-5019 (2010)]
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Automatic sensitivity adjustment for a curvature sensor
Aglae Kellerer, Mark Chun, Christ Ftaclas
There are different techniques for sensing wavefront phase distortions due to atmospheric turbulence. Curvature sensors are practical because their sensitivity is adjustable to the prevailing atmospheric conditions. Even at the best sites, the turbulence intensity has been found to vary at times ... [Appl. Opt. 49, G140-G147 (2010)]
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