Low temperature operation of APD for quantum cryptographic applications

Kale, Zuhal
This thesis explains low temperature operation of an InGaAs Avalanche Photo Diode (APD) cooled using thermoelectric coolers in order to utilize in the quantum cryptographic applications. A theoretical background for the equipment used in the experiment was provided. Circuitry and mechanics used for the low temperature operation were designed. Performance measures for APD were explained and experiment results were presented.


Near-infrared Hong-Ou-Mandel interference on a silicon quantum photonic chip
Xu, Xinan; Xie, Zhenda; Zheng, Jiangjun; Liang, Junlin; Zhong, Tian; Yu, Mingbin; Kocaman, Serdar; Lo, Guo-Qiang; Kwong, Dim-Lee; Englund, Dirk R.; Wong, Franco N.C.; Wong, Chee Wei (The Optical Society, 2013-02-25)
Near-infrared Hong-Ou-Mandel quantum interference is observed in silicon nanophotonic directional couplers with raw visibilities on-chip at 90.5%. Spectrally-bright 1557-nm two-photon states are generated in a periodically-poled KTiOPO4 waveguide chip, serving as the entangled photon source and pumped with a self-injection locked laser, for the photon statistical measurements. Efficient four-port coupling in the communications C-band and in the high-index-contrast silicon photonics platform is demonstrated,...
Low temperature crystallization of amorphous silicon by gold nanoparticle
Karaman, M.; AYDIN, MURAT; Sedani, S. H.; ERTÜRK, KADİR; Turan, Raşit (Elsevier BV, 2013-08-01)
Single crystalline Si thin film fabricated on glass substrate by a process called Solid Phase Crystallization (SPC) is highly desirable for the development of high efficiency and low cost thin film solar cells. However, the use of ordinary soda lime glass requires process temperatures higher than 600 degrees C. Crystallization of Si film at around this temperature takes place in extremely long time exceeding 20 h in most cases. In order to reduce this long process time, new crystallization techniques such a...
Thermal refocusing method for spaceborne high-resolution optical imagers
Selimoglu, Ozgur; Ekinci, Mustafa; Karci, Ozgur (2016-05-20)
We describe the design of a thermal refocusing method for spaceborne high-resolution imagers where Korsch optical design is usually implemented. The secondary mirror is made of aluminum, a high thermal expansion coefficient material, instead of conventional zero-expansion glass ceramics. In this way, the radius of the curvature can be controlled by means of temperature change of the mirror. Change in the radius of curvature also changes the effective focal length of the camera which is used for compensation...
Design and analysis of ultrashort femtosecond laser amplifiers
Doğan, Ersin; Bilikmen, Kadri Sinan; Department of Physics (2006)
This thesis presents a compact femtosecond laser amplifier design for optical preamplifiers and power amplifiers consist of theoretical perspective, simulations to analyze and optimize beam performance. The propagation through optical media is simulated for every optical component such as mirrors and nonlinear crystal separately and suggested realignment of these components required increasing amplifier performance. Finally Gaussian beam propagation and aberration compensation has been conducted.
High temperature microstructural stability and recrystallization mechanisms in 14YWT alloys
Aydoğan Güngör, Eda; Takajo, S.; Vogel, S. C.; Maloy, S. A. (Elsevier BV, 2018-04-01)
In-situ neutron diffraction experiments were performed on room temperature compressed 14YWT nanostructured ferritic alloys at 1100 degrees C and 1150 degrees C to understand their thermally activated static recrystallization mechanisms. Existence of a high density of Y-Ti-O rich nano-oxides ( and {112} texture components during annealing, in contrast to the conventional recrystallization textures in body centered cubic alloys. Furthermore, nano-oxide size, shape, density and distribution are considerably di...
Citation Formats
Z. Kale, “Low temperature operation of APD for quantum cryptographic applications,” M.S. - Master of Science, Middle East Technical University, 2005.