arXiv subjects

A. Sayem

Publications and source records attributed to A. Sayem.

3 recordsLinked to original sources

arXiv2025

Periodically poled thin-film lithium niobate ring Mach Zehnder coupling interferometer for efficient quantum frequency conversion

Quantum frequency conversion is unavoidable for a true quantum communication network as most quantum memories work in the visible spectrum. Here, we propose a unique design of a quantum frequency converter based on a ring-Mach Zehnder interferometer coupled with a periodically poled thin-film lithium niobate waveguide. The proposed device can be-directionally convert quantum signals i.e. single photons from quantum memory such as SiV-center in diamond to the telecom wavelength offering conversion efficiency as high as 90% at mW pump power with noise photon rate below 0.1Hz.

quant-ph↗

arXiv2024

Periodically poled thin-film lithium niobate ring Mach Zehnder coupling interferometer as an efficient quantum source of light

Single photons and squeezed light are the two primary workhorses for quantum computation and quantum communication. Generating high-efficiency single photons with high purity and heralding efficiency is the prerequisite for photonic quantum computers. At the same time, generating high-efficiency scalable squeezed light is the prerequisite for continuous variable quantum computing along with sensing applications. Here, we propose a symmetric ring-Mach-Zehnder interferometer (RMZI), which includes a periodically poled lithium niobate (PPLN) waveguide as an efficient source of squeezed light and a single-photon source. We numerically show that our proposed design can generate tunable squeezed light with a squeezing level higher than -12dB with sub-milli-watt (mW) pump power. The proposed device can also generate single photons with purity as high as 99(95)% with heralding efficiency 94(99)% using only 20ps long pulses. Our proposed design is fully compatible with current fabrication technology.

physics.optics↗

arXiv2023

Photonic quantum computing on thin-film lithium niobate: Part I Design of an efficient heralded single photon source co-integrated with superconducting detectors

Photonic quantum computers are currently one of the primary candidates for fault-tolerant quantum computation. At the heart of the photonic quantum computation lies the strict requirement for suitable quantum sources e.g. high purity, high brightness single photon sources. To build a practical quantum computer, thousands to millions of such sources are required. In this article, we theoretically propose a unique single-photon source design on a thin-film lithium niobate (TFLN) platform co-integrated with superconducting nanowire single-photon detectors. We show that with a judicial design of single photon source using thin film periodically poled lithium waveguides (PPLN), back-illuminated grating couplers (GCs) and directly bonded or integrated cavity coupled superconducting nanowire single-photon detectors (SNSPDs) can lead to a simple but practical high efficiency heralded single-photon source using the current fabrication technology. Such a device will eliminate the requirement of out coupling of the generated photons and can lead to a fully integrated solution. The proposed design can be useful for fusion-based quantum computation and for multiplexed single photon sources and also for efficient on-chip generation and detection of squeezed light.

quant-ph↗