Creating Bright Single Photon Sources with Metasurfaces for Quantum Information Technology

Recently, quantum information technologies (QIT) have been developing very actively and quickly. The epitaxial quantum dot (EQD) is a promising candidate as a light source for QIT. Thanks to its discrete density of states and cascade emission process, we can always obtain a single photon from the EQD once it’s excited. However, creating bright single photon sources based on EQD is quite a challenge due to the large portion of total internal reflection of quantum dot emission at the air/semiconductor boundary. To overcome this limitation and achieve 100% collection, a number of single photon sources have been developed based on both cavity and non-cavity designs, including well-known devices such as micropillars and nanowires. We are attempting to combine single EQDs with a metasurface to improve photon collection efficiency. This thin metasurface, composed of aSi pillars and holes, helps to manipulate the propagation of light emitted from a single EQD and extract it vertically. This device was fabricated in the nanofab at Penn State University and won first place in the scientific category of the 15th Materials Visualization Competition (MVC15).