Executive Summary : | Scaling the gate length has been at the heart of improving the device performance of conventional transistors. Improvement in the performance of the conventional charge-based devices has been limited in recent years as the further scaling of the gate length has been limited. Efforts are now directed towards devices with novel materials and functionalities to circumvent this problem and continue with the performance improvements. Quantum devices and technologies are now at the center of this attraction due to their immense possibilities and significant performance improvements compared to that offered by conventional charge-based devices. The quantum bits (qubits) are very different from the charge-based units used to identify a device's states. Several kinds of qubits have been proposed by various groups, including diamond NV center, trapped ion qubits, quantum-dot qubits, nuclear spin, Majorana qubits, and photonic qubits. The polarization of a single photon has particularly drawn interest in this regard due to its ease of preparation and manipulation using conventional optics. The single-photon as qubits are relevant for both diamond NV centers and photonic qubits. While sources of the single-photon source are being looked at aggressively, detecting the single-photon has also remained challenging. Various types of detectors are being explored, including Hanbury Brown-Twiss (HBT), coherence detection using Mach-Zehnder interferometer, and indistinguishability detection by the Hong-Ou-Mandel detector. These single-photon detectors find wide spead applications, including quantum communication, quantum cryptography, quantum metrology, lidar, medical physics quantum information processing. This proposal will design and develop these interferometers with high accuracy and efficiency suitable for these applications. |