0000000000204511
AUTHOR
Amir Shemer
Laser Vibrometer Interferometry for Speckle Patterns Tracking Systems
In this paper we propose a modulated laser system combining a speckle pattern tracking method for surface tilting changes sensing with an interferometer for surface z-axis changes sensing at the same scan time.
Superresolved imaging based on wavelength multiplexing of projected unknown speckle patterns
We propose a method for resolution enhancement of a diffraction limited optical system based on the capture of a set of low resolution images. These images are obtained after projection of an ensemble of unknown speckle patterns on top of the high resolution object that is to be imaged. Each speckle pattern is generated by the same thin (and unknown) diffuser, but illuminated with a slightly different wavelength. From the ensemble of low resolution images, we obtain a system of equations that can be solved in an iterative manner that enables reconstruction of the high resolution object. As a result, we also achieve the projected high resolution speckle patterns used for the encoding.
Modified morphological correlation based on bit-map representations.
Pattern recognition with high discrimination can be achieved with a morphological correlator. A modification of this correlator is carried out by use of a binary slicing process instead of linear thresholding. Although the obtained correlation result is not identical to the conventional morphological correlation, it requires fewer calculations and provides even higher discrimination. Two optical experimental implementations of this modified morphological correlator as well as some experimental results are shown.
Augmentative Alternative Communication using Eyelid Movement Remote Detection by Speckle Patterns Tracking System for Amyotrophic Lateral Sclerosis Disease
The implementation of augmentative alternative communication optical device for ALS speech problem is presented. The sensor is based on temporal tracking of back-reflected secondary speckle patterns generated when illuminating an eyelid with a laser.
Noncontact speckle-based optical sensor for detection of glucose concentration using magneto-optic effect
We experimentally verify a speckle-based technique for noncontact measurement of glucose concentration in the bloodstream. The final device is intended to be a single wristwatch-style device containing a laser, a camera, and an alternating current (ac) electromagnet generated by a solenoid. The experiments presented are performed in vitro as proof of the concept. When a glucose substance is inserted into a solenoid generating an ac magnetic field, it exhibits Faraday rotation, which affects the temporal changes of the secondary speckle pattern distributions. The temporal frequency resulting from the ac magnetic field was found to have a lock-in amplification role, which increased the observ…
Super resolving optical system based on spectral dilation
Time multiplexing is a common approach for achieving super resolution. The basic method involves moving two grating one is in front of the object and the other one in front of the camera. In this paper, we present a novel approach for obtaining super resolution not by shifting a grating, but by using its various dilations for obtaining the required encoding and decoding of information.
An Optical Remote Sensor for Fingerprint Identification using Speckle Pattern
The implementation of a simple, inexpensive optical device for remote fingerprint identification is presented. The sensor is based on temporal tracking of back-reflected secondary speckle patterns generated while illuminating a finger with a laser.
Improved superresolution in coherent optical systems.
Objects that temporally vary slowly can be superresolved by the use of two synchronized moving masks such as pinholes or gratings. This approach to superresolution allows one to exceed Abbe’s limit of resolution. Moreover, under coherent illumination, superresolution requires a certain approximation based on the time averaging of intensity rather than of field distribution. When extensive digital postprocessing can be incorporated into the optical system, a detector array and some postprocessing algorithms can replace the grating that is responsible for information decoding. In this way, no approximation is needed and the synchronization that is necessary when two gratings are used is simpl…
Superresolving optical system with time multiplexing and computer decoding
Objects that have slow temporal variations may be superresolved with two moving masks such as pinhole or grating. The first mask is responsible for encoding the input image, and the second one performs the decoding operation. This approach is efficient for exceeding the resolving capability beyond Abbe’s limit of resolution. However, the proposed setup requires two physical gratings that should move in a synchronized manner. We propose what is believed to be a novel configuration in which the second grating responsible for the information decoding is replaced with a detector array and some postprocessing digital procedures. In this way the synchronization problem that exists when two gratin…