IOSR-JAP   Volume-8 ~ Issue-6 ~ Nov-Dec 2016

ABSTRACT: In this work, we studied the effects of surface density of quantum dots and the mean size of quantum dots (QDs) on dynamics of quantum dot laser (QDL). Here, detailed theoretical study of the parameters effect on some properties of GaInAsp/InP QDL system at 1.55 μm wavelength. It includes the following variables: the threshold current density, confined level occupancy, internal loss coefficient, optical confinement layer. In addition, it is diagnosed their role to determining the amount of the maximum temperature of laser. By studying a different control ranges of surface density and the mean size of QDs that identified optimum values for them. That gives better stability of the system's work near the room temperature compared to experimental results.

Keywords:: Quantum dot lasers, Mean size of quantum dots, Surface density of QDs, GaInAsP/InP laser.

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[2] R. M. Hassan, C. A. Emshary and S. I. Easa, "Quantum Dot Laser: Turn-on Dynamics and the Operation Characteristics", LAP LAMBERT Academic Publishing, 2016.
[3] G. M. Ali, "Characteristic Temperature and Lowest Excitation Energy of Semiconductor QD laser", MSc. thesis, basrah university, 2015.
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[5] Yuchang .Wu "Theory of Modulation Response of Semiconductor Quantum Dot Lasers", PhD. thesis, Virginia Polytechnic Institute and State University, USA, 2013.

ABSTRACT: The theory of elastic constant is capable to explain the concept of Hook's law. According to this, a small amount of deformation in a solid is directly proportional to stress and the strain components are linear function of stress components. The ratio of stress to strain is known as the modulus of elasticity. The third and higher order terms are neglected in the case of harmonic approximation. Some derivations from Hook's law at small deformation has been reported by some physicists which is mainly due to the omission of higher order terms of the strain energy. This reason and derivation motivated the workers to focus their attention to Third Oreder Elastic Constants(TOECs).............

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ABSTRACT: Diabetes is the leading cause of blindness in western countries in the productive age groups. For diabetic retinopathy the major risk is the presence of diabetic. Early detection can potentially reduce the risk of blindness. The eye is one of the most important end organs for complications of diabetes. There are two types of ocular diabetic complications: direct and indirect. Diabetic retinopathy is the primary direct complication of diabetes in the eye. There are two main categories of DR, Non-proliferative (Non-PDR) and Proliferative (PDR). In this work a new technique is presented for automatic screening of diabetic Retinopathy based on Comprehensive Spectral-Textural features which are two fundamental patterns elements that can be interpreted by human. To extract spectral features parameters (Bi-spectral invariant features at different angles of orientation)the gray level retina images are subjected to Radon transform which convert the 2D image in to 1D image vector which introduced to the HOS (Higher Order Statistic) Scheme.............

Keywords: CAD, Diabetic retinopathy, Radon transform, Spectral-Textural Features, KNN.

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[3]. GiriBabuKande, April, 2010. Feature Extraction from Fundus Images to Analyze Diabetic Retinopathy. Research and Development Cell Jawaharlal Nehru Technological University Hyderabad Kukatpally, Hyderabad – 500 085, India.
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[5]. AbhirBhalerao et al. 2008. Robust Detection of Microaneurysms for Sight Threatening Retinopathy Screening. IEEE Computer society.