S. Rosen, G. Y. Sirat, H. Ilan, and A. J. Agranat, “A sub wavelength localization scheme in optical imaging using conical diffraction,” Optics Express, vol. 21, no. 8, pp. 101338, 2013.Abstract
In this paper we present a scheme for the acquisition of high temporal resolution images of single particles with enhanced lateral localization accuracy. The scheme, which is implementable as a part of the illumination system of a standard confocal microscope, is based on the generation of a vector beam that is manipulated by polarimetry techniques to create a set of illumination PSFs with different spatial profiles. The combination of data collected in different illumination states enables the extraction of spatial information obscured by diffraction in the standard imaging system. An implementation of the scheme based on the utilization of the unique phenomenon of conical diffraction is presented, and the basic strategy it provides for enhanced localization in the diffraction limited region is demonstrated.
N. Sapiens and A. J. Agranat, “Full C-Band Tunable Laser based on Electroholography,” Optics Letters , vol. 38, pp. 2131-2133, 2013.Abstract
A tunable laser that spans the entire C band is presented. The laser consists of an Er-doped fiber amplifier gain medium, a fiber ring resonator, and an electroholography-based tuning mechanism. The electrohologram used is in the g44 configuration where the Bragg condition can be electrically tuned for a specific wavelength. Two laser architectures are presented, one in which the diffracting beam and one in which the direct beam of the electrohologram is used as the laser output. Switching time between wavelengths is limited by the gain medium relaxation time, since the electrohologram switching time is less than 1 ns.
Y. Kabessa, V. Korouma, H. Ilan, S. Yagur-Kroll, S. Belkin, and A. J. Agranat, “Simultaneous quantification of the fluorescent responses of an ensemble of bacterial sensors.,” Biosensors & Bioelectronics, vol. 49, pp. 394 - 398, 2013. Publisher's VersionAbstract
Abstract: Bacterial bioreporters are genetically engineered microbial strains capable of detecting specific chemicals, groups of chemicals or global biological effects such as toxicity or genotoxicity. A scheme for simultaneous selective detection of the fluorescent signals emitted by a bacterial biosensor array, able to detect four different types of toxicants, using a single photodetector (photomultiplier) is presented. The underlying principle of the scheme is to convert the spatially distributed signals from all the elements in the array to temporally distributed frequency multiplexed signals at the output of the photodetector. Experimental proof of this concept is demonstrated in a four-channel system, in which low power (a few tens of picowatts) fluorescent signals produced by the bacterial sensors are measured, while maintaining a wide dynamic range of detection (more than 3 orders of magnitude). Simultaneous monitoring of concentrations down to a few mg/l of different chemicals in a liquid sample is demonstrated. [Copyright &y& Elsevier]Copyright of Biosensors & Bioelectronics is the property of Elsevier Science Publishing Company, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)