Nanofabrication of photonic structure for tin-vacancy center in diamond

Abstract

Quantum technology is a method that utilizes photons to encode information, leading to enhanced security. The origins of photonic quantum technologies can be traced back to the fundamental principles of quantum optics, which have long been used as a foundation for exploring concepts in quantum information science. Commercial quantum key distribution (QKD) systems are available, which utilize quantum systems to communicate information and provide enhanced security. Single-photon emitters are essential for many quantum technologies. These quantum technologies have sparked interest in diamond vacancy-impurity defects, crucial for various quantum applications. Diamond is a promising material for creating photonic devices because of its outstanding properties, including a high refractive index of 2.4, a wide band gap of 5.5 eV, a transparency window, and the ability to handle immense power. Diamond defects have demonstrated the potential for quantum emitters, such as the group IV color centers, which include the Si-, Ge-, Sn-, and Pb vacancies. Among them, negative charged Tin -vacancy centers (SnV-) in diamonds show great potential as quantum emitters due to their impressive optical and spin attributes. Single-emitter measurements suggest that the SnV has strong potential for quantum optics and quantum networking applications. Prospering quantum photonic devices at visible wavelengths are obtained by reactive ion beam angled etching in such devices as the diamond angled-etching method. Achievement of ICP-RIE of diamond photonic crystal nanobeams and waveguides is related to the effective type of mask used in electron beam lithography. The performance of the mask depends on its thickness, selectivity, aspect ratio, and sidewall smoothness which impacts the etch profiles and optical performance. Also, the 5 nm Chromium layer before the FOx 25 mask is applied to have the optimum etch profile and optical performance. This thesis explores the characterization, fabrication, and development of a structure consisting of a grating coupler nanobeam waveguide with shallow implanted.