This work mainly demonstrates the development process of an ultra-broad band antireflection (AR) ... more This work mainly demonstrates the development process of an ultra-broad band antireflection (AR) coating that maximizes the optical performance of germanium optical elements. A multilayer stack exhibiting high efficient AR performance on Ge consists of thin multi-layers of aluminum oxide (Al2O3) and germanium (Ge) named as low and high refractive index layer materials. A three-layer design with a very tight thickness tolerance (3%) was optimized by Optilayer software. Al2O3 and Ge layers were deposited by a plasma assisted e-beam evaporation system. Ultra-high efficient multilayer AR coating on Ge has a base reflectance 0.005% at 3550 nm and an average reflectance of 0.256% over the entire mid wave infrared spectrum. Multilayer AR coating on Ge offers lower base and average reflectance than the works reported before. Moreover, AR coating on Ge offers a cost effective process cycle due to its number of layers and its thickness for providing ultra-broadband and high efficient optical performance for mid wave infrared electro-optical applications.
Super resolution optics have been developed for surpassing the resolution limit of conventional o... more Super resolution optics have been developed for surpassing the resolution limit of conventional optical components. As an application of the super resolution, micro diffraction based optical devices have an important role to exceed the resolution limit of the conventional components. Photon sieves are a design of optical components based on the principle of micro-diffraction optics. In this thesis, the design and production of photon sieves are aimed by using photolithography as a micro-fabrication method. In this context, the study is grouped under two main headings. In the first step, a simulation code was developed to design the diffraction optics and to investigate the focusing properties upon the design. With the help of this code, the intensity distribution and the resolution properties which determine the optical performance of photon sieves have been investigated. According to their usage areas three different photon sieve models were designed and their properties were exami...
The two important parameters, to evaluate the performance of the photon sieves quantitatively, ar... more The two important parameters, to evaluate the performance of the photon sieves quantitatively, are the intensity and resolution at the focus plane. Both high-intensity and super-resolution depend on the ratio of the diameter (d) of each pinhole to the width (w) of the related Fresnel zone: the d/w ratio. The size deviations in the produced pinholes may adversely affect the optical performance of the photon sieves. The mispositioned and imperfectly-shaped pinholes cause the super-resolution at the focus to be disrupted. The photon sieves are produced by using two sub-methods of maskless lithography: lift-off and wet chemical etching. Although designed to be constant of 1, the d/w ratio was measured to widen gradually for both chemical-etched and lift-off samples. It is revealed the optical performance of the photon sieves may be enhanced as a result of gradual increase of the d/w ratio, compared to the structure of constant d/w ratio.
Silicon nanocrystals (nc-Si) in an amorphous silicon oxide a-SiOx:H matrix, has generated signifi... more Silicon nanocrystals (nc-Si) in an amorphous silicon oxide a-SiOx:H matrix, has generated significant interest in the nc-Si/a-SiOx:H system because of its potential applications in electronics, optoelectronics, and optical devices in Si-compatible technologies. At present, however, many fundamental aspects of the synthesis and structure of nc-Si in a-SiOx:H are still uncertain, despite significant efforts over recent years.
This work mainly demonstrates the development process of an ultra-broad band antireflection (AR) ... more This work mainly demonstrates the development process of an ultra-broad band antireflection (AR) coating that maximizes the optical performance of germanium optical elements. A multilayer stack exhibiting high efficient AR performance on Ge consists of thin multi-layers of aluminum oxide (Al2O3) and germanium (Ge) named as low and high refractive index layer materials. A three-layer design with a very tight thickness tolerance (3%) was optimized by Optilayer software. Al2O3 and Ge layers were deposited by a plasma assisted e-beam evaporation system. Ultra-high efficient multilayer AR coating on Ge has a base reflectance 0.005% at 3550 nm and an average reflectance of 0.256% over the entire mid wave infrared spectrum. Multilayer AR coating on Ge offers lower base and average reflectance than the works reported before. Moreover, AR coating on Ge offers a cost effective process cycle due to its number of layers and its thickness for providing ultra-broadband and high efficient optical performance for mid wave infrared electro-optical applications.
Super resolution optics have been developed for surpassing the resolution limit of conventional o... more Super resolution optics have been developed for surpassing the resolution limit of conventional optical components. As an application of the super resolution, micro diffraction based optical devices have an important role to exceed the resolution limit of the conventional components. Photon sieves are a design of optical components based on the principle of micro-diffraction optics. In this thesis, the design and production of photon sieves are aimed by using photolithography as a micro-fabrication method. In this context, the study is grouped under two main headings. In the first step, a simulation code was developed to design the diffraction optics and to investigate the focusing properties upon the design. With the help of this code, the intensity distribution and the resolution properties which determine the optical performance of photon sieves have been investigated. According to their usage areas three different photon sieve models were designed and their properties were exami...
The two important parameters, to evaluate the performance of the photon sieves quantitatively, ar... more The two important parameters, to evaluate the performance of the photon sieves quantitatively, are the intensity and resolution at the focus plane. Both high-intensity and super-resolution depend on the ratio of the diameter (d) of each pinhole to the width (w) of the related Fresnel zone: the d/w ratio. The size deviations in the produced pinholes may adversely affect the optical performance of the photon sieves. The mispositioned and imperfectly-shaped pinholes cause the super-resolution at the focus to be disrupted. The photon sieves are produced by using two sub-methods of maskless lithography: lift-off and wet chemical etching. Although designed to be constant of 1, the d/w ratio was measured to widen gradually for both chemical-etched and lift-off samples. It is revealed the optical performance of the photon sieves may be enhanced as a result of gradual increase of the d/w ratio, compared to the structure of constant d/w ratio.
Silicon nanocrystals (nc-Si) in an amorphous silicon oxide a-SiOx:H matrix, has generated signifi... more Silicon nanocrystals (nc-Si) in an amorphous silicon oxide a-SiOx:H matrix, has generated significant interest in the nc-Si/a-SiOx:H system because of its potential applications in electronics, optoelectronics, and optical devices in Si-compatible technologies. At present, however, many fundamental aspects of the synthesis and structure of nc-Si in a-SiOx:H are still uncertain, despite significant efforts over recent years.
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Papers by KEMAL RÜZGAR
the nc-Si/a-SiOx:H system because of its potential applications in electronics, optoelectronics, and optical devices in Si-compatible
technologies. At present, however, many fundamental aspects of the synthesis and structure of nc-Si in a-SiOx:H are still uncertain,
despite significant efforts over recent years.
the nc-Si/a-SiOx:H system because of its potential applications in electronics, optoelectronics, and optical devices in Si-compatible
technologies. At present, however, many fundamental aspects of the synthesis and structure of nc-Si in a-SiOx:H are still uncertain,
despite significant efforts over recent years.