Related papers: Telecom-band Multi-Type Spontaneous Parametric Dow…
We propose a non-uniform modulation of $\chi^{(2)}_{xyz}$ to significantly enhance photon pair generation efficiency via spontaneous parametric down-conversion in modal phase-matched semiconductor waveguides. This approach enables…
We report on theoretical and experimental demonstration of high-efficiency coupling of two-photon entangled states produced in the nonlinear process of spontaneous parametric down conversion into a single-mode fiber. We determine…
Generation and characterization of entanglement are crucial tasks in quantum information processing. A hypothesis testing scheme for entanglement has been formulated. Three designs were proposed to test the entangled photon states created…
Parity-time-symmetric ($\mathcal{PT}$-symmetric) optical waveguide couplers have become a key component for integrated optics. They offer new possibilities for fast, ultracompact, configurable, all-optical signal processing. Here, we study…
Spontaneous parametric downconversion (SPDC) has been a key enabling technology in exploring quantum phenomena and their applications for decades. For instance, traditional SPDC, which splits a high energy pump photon into two lower energy…
We present an experimental method to measure the transverse spatial quantum state of an optical field in coordinate space at the single-photon level. The continuous-variable measurements are made with a photon-counting, parity-inverting…
The importance of integrated quantum photonics in the telecom band resides on the possibility of interfacing with the optical network infrastructure developed for classical communications. In this framework, femtosecond laser written…
We suggest the generation of photon pairs in a thermally induced nonlinear periodically-poled silica fiber by spontaneous parametric down-conversion. Photons are generated directly in eigenstates of optical angular momentum. Photons in a…
We present a direct measurement of the spatiotemporal coherence of parametric down-conversion in the range of negative group-velocity dispersion. In this case, the frequency-angular spectra are ring-shaped and temporal coherence is coupled…
We present designs for variably polarizing beam splitters. These are beam splitters allowing the complete and independent control of the horizontal and vertical polarization splitting ratios. They have quantum optics and quantum information…
Parametric down-conversion can produce photons that are entangled both in polarization and in space. Here we show how the spatial entanglement can be used to purify the polarization entanglement using only linear optical elements. Spatial…
Quantum information technology strongly relies on coupling of optical photons with narrowband quantum systems, such as quantum dots, color centers, and atomic systems. This coupling requires matching the optical wavelength and bandwidth to…
The ability to inscribe information on single photons at high speeds is a crucial requirement for quantum applications such as quantum communication and measurement-based photonic quantum computation. Nowadays, most experimental…
Spatial polarization independent (SPI) parametric conversion is the basis of many optical applications, such as SPI frequency interface for communication channels carried by vector modes and upconversion detection for polarization-resolved…
We present a fiber-based source of polarization-entangled photon pairs that is well suited for quantum communication applications in the 1.5$\mu$m band of standard telecommunication fiber. Quantum-correlated signal and idler photon pairs…
Nonlinear optical processes of spatially structured light, including optical vortex and vector optical fields, have stimulated a lot of interesting physical effects and found a variety of important applications ranging from optical imaging…
Multimode entanglement is an essential resource for quantum information in continuous-variable systems. Light-based quantum technologies will arguably not be built upon table-top bulk setups, but will presumably rather resort to integrated…
Non-classical multi-photon and number states attracts many people because of their wide applications in fundamental quantum mechanics tests, quantum metrology and quantum computation, therefore it is a longstanding aim to generate such…
Entanglement-based quantum networks require quantum photonic interfaces between stationary quantum memories and photons, enabling entanglement distribution. Here we present such a photonic interface, designed for connecting a $^{40}$Ca$^+$…
Spontaneous parametric down-conversion (SPDC) is one of the most versatile nonlinear optical techniques for the generation of entangled and correlated single-photon pairs. However, it suffers from very poor efficiency leading to extremely…