A5037554581- Quantum Information and Cryptography
- Optical Network Technologies
- Photonic and Optical Devices
- Quantum optics and atomic interactions
- Advanced Fiber Laser Technologies
- Quantum Mechanics and Applications
- Quantum Computing Algorithms and Architecture
- Advanced Photonic Communication Systems
- Mechanical and Optical Resonators
- Laser-Matter Interactions and Applications
- Neural Networks and Reservoir Computing
- Semiconductor Lasers and Optical Devices
- Photonic Crystal and Fiber Optics
- Orbital Angular Momentum in Optics
- Photorefractive and Nonlinear Optics
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Advanced Fluorescence Microscopy Techniques
- Chaos-based Image/Signal Encryption
- Advanced Optical Sensing Technologies
- Random lasers and scattering media
- Spectroscopy and Quantum Chemical Studies
- Advanced Fiber Optic Sensors
- Solid State Laser Technologies
- Advanced Optical Network Technologies
Parul University
2024-2025
Northwestern University
2015-2024
University of Mysore
2024
Argonne National Laboratory
2023
PES University
2023
Guru Jambheshwar University of Science and Technology
2022
Netaji Subhas University of Technology
2021
Monash University Malaysia
2020
University of Nevada, Reno
2019
Pusan National University
2018
We present a fiber-based source of polarization-entangled photons that is well suited for quantum communication applications in the 1550 nm band standard fiber-optic telecommunications. Polarization entanglement created by pumping nonlinear-fiber Sagnac interferometer with two time-delayed orthogonally polarized pump pulses and subsequently removing time distinguishability passing parametrically scattered signal idler photon pairs through piece birefringent fiber. Coincidence detection...
.We experimentally study the generation of correlated pairs photons through four-wave mixing (FWM) in embedded silicon waveguides. The waveguides, which are designed to exhibit anomalous group-velocity dispersion at wavelengths near 1555 nm, allow phase matched FWM and thus efficient pair-wise non-degenerate signal idler photons. Photon counting measurements yield a coincidence-to-accidental ratio (CAR) around 25 for (idler) photon production rate about 0.05 per pulse. We characterize...
We have observed optical phase-conjugate gain (>50) in sodium vapor, using low-intensity pump lasers (1 W/cm2), with a response time of the order 1 μs. Coherent population trapping is experimentally identified as mechanism. A theoretical model presented that supports these observations by showing coherent can write large-amplitude nonlinear-optical gratings at laser intensities well below those needed to saturate transitions.
An experimental scheme is proposed by which the quantum states of two light beams different frequencies can be interchanged. With this it possible to generate frequency-tunable squeezed for spectroscopic applications.
In this letter, we present a source of quantum-correlated photon pairs based on parametric fluorescence in fiber Sagnac loop. The are generated the 1550-nm fiber-optic communication band and detected with InGaAs-InP avalanche photodiodes operating gated Geiger mode. A generation rate > 10/sup 3/ pairs/s is observed, which limited by detection electronics at present. We also demonstrate nonclassical nature correlations pairs. This source, given its spectral properties robustness, well suited...
Quantum frequency conversion, a process with which an input beam of light can be converted into output different while preserving the quantum state, is experimentally demonstrated for first time. Nonclassical intensity correlation (\ensuremath{\simeq}3 dB) between two beams at 1064 nm used as property. When one from to 532 nm, nonclassical correlations (\ensuremath{\simeq}1.5 appear up-converted and remaining beam. Our measurements are in excellent agreement theory conversion. The...
We have measured the photon statistics of random lasers with resonant feedback. With an increase pump intensity, number distribution in a single mode changes continuously from Bose-Einstein at threshold to Poisson well above threshold. The second-order correlation coefficient drops gradually 2 1. By comparing laser feedback and that nonresonant feedback, we illustrate very different lasing mechanisms for two types lasers.
We demonstrate theoretically and experimentally that secure communication using intermediate-energy (mesoscopic) coherent states is possible. Our scheme different from previous quantum cryptographic schemes in a short secret key explicitly used which noise hides both the bit key. This encryption allows optical amplification. New avenues are open to communications at high speeds fiber-optic or free-space channels.
Pulsed twin beams of light have been generated using an optical-parametric amplifier that is pumped by the second harmonic a mode-locked and Q-switched neodymium:yttrium aluminum garnet laser. The intensity noise levels on direct-detected signal idler are found to be correlated more than 15 dB, subtracted falls below quantum limit 6 dB (75%). To our knowledge, this first observation pulsed light, yields highest quantum-noise reduction observed in any experiment date. Our measurements...
We have generated squeezed-state light through forward four-wave mixing in sodium vapor as verified by homodyne detection. Optical phase-sensitive noise with a minimum falling 4% below the shot-noise limit was observed.
We report the observation of low-light level optical interactions in a tapered nanofiber (TNF) embedded hot rubidium vapor. The small mode area plays significant role properties vapor Rb-TNF system, allowing nonlinear with nW powers even presence transit-time dephasing rates much larger than intrinsic linewidth. demonstrate absorption and V-type electromagnetically induced transparency cw below 10 nW, comparable to best results any Rb-optical waveguide system. good performance flexibility...
Just as classical information technology rests on a foundation built of interconnected information-processing systems, quantum (QIT) must do the same. A critical component such systems is interconnect, device or process that allows transfer between disparate physical media, for example, semiconductor electronics, individual atoms, light pulses in optical fiber, microwave fields. While interconnects have been well engineered decades realm technology, (QuICs) present special challenges, they...
We demonstrate greatly improved results for the production of correlated photon-pairs using four-photon scattering process in silica fiber. achieve a true-coincidence-count to accidental-coincidence-count ratio greater than 10, when photon-pair rate is about 0.04 /pulse. This represents four-fold improvement over our previous results. The contribution spontaneous Raman scattering, primary cause uncorrelated photons that degrades fidelity this source, reduced by decreasing wavelength detuning...
We report what we believe to be the first experimental demonstration of nondegenerate four-wave mixing in a microstructure fiber. The effect χ3 nonlinearity is enhanced such fiber because small core area, and achieve phase matching by operating near zero-dispersion wavelength ≃750 nm. have observed parametric gains more than 13 dB 6.1-m-long with pump peak power only 6 W. compare our gain results those predicted theory explore effects Raman shift (or) amplification cascaded nonlinear mixing.
We demonstrate, for the first time to our knowledge, optical parametric oscillation based on four-wave mixing in microstructure fiber. The measured wavelength-tunability range of device (40 nm) and threshold-pump peak power (34.4 W) are good agreement with theory fibers. ellipticity fiber's polarization modes allows be implemented a relatively simple Fabry-Perot configuration. Spectral peaks that due cascaded-mixing processes easily observed setup, which may provide way extend tunability...
A team of researchers from the Massachusetts Institute Technology (MIT) and Northwestern University (NU) is developing a system for long-distance, high- delity qubit tele-portation. Such will be required if future quantum computers are to linked together into Internet. This paper presents recent progress that MIT/NU has made, beginning with review teleportation architecture its loss-limited performance analysis.
We experimentally demonstrate, for the first time to our knowledge, a phase-sensitive amplifier based on frequency nondegenerate parametric amplification in optical fiber, where input signal-idler pair is prepared all-optically. Using two fiber-optic sections separated by fiber-based wavelength-dependent phase shifter, we observe and investigate gain profile 1550 nm region both theoretically. The realized scheme automatically generates gain-defining that environmentally stable, making it...
To deploy and operate a quantum network which utilizes existing telecommunications infrastructure, it is necessary to be able route entangled photons at high speeds, with minimal loss signal-band noise, and--most importantly--without disturbing the photons' state. Here we present switch fulfills these requirements characterize its performance single photon level. Furthermore, because this type of couples temporal spatial degrees freedom, provides an important new tool encode multiple-qubit...
Quantum frequency conversion (QFC) of photonic signals preserves quantum information while simultaneously changing the signal wavelength. A common application QFC is to translate wavelength a compatible with current fiber-optic infrastructure shorter more high quality single-photon detectors and optical memories. Recent work has investigated use manipulate measure specific temporal modes (TMs) through tailoring pump pulses. Such scheme holds promise for multidimensional state manipulation...
Abstract This paper presents a platform combining an inverse electromagnetic design computational method with additive manufacturing to and fabricate all-dielectric metadevices. As opposed conventional flat metasurface-based devices that are composed of resonant building blocks resulting in narrow band operation, the proposed approach creates non-resonant, broadband (Δ λ /λ up >50%) metadevices based on low-index dielectric materials. High-efficiency (transmission >60%), thin (≤2λ)...
The Illinois Express Quantum Network (IEQNET) is a program to realize metropolitan scale quantum networking over deployed optical fiber using currently available technology. IEQNET consists of multiple sites that are geographically dispersed in the Chicago area. Each site has one or more nodes (Q-Nodes) representing communication parties network. Q-Nodes generate measure signals such as entangled photons and communicate measurement results via standard, classical conventional processes....
We used a spatially broadband optical parametric amplifier for image amplification. In the phase-sensitive configuration of amplifier, we observed noiseless amplification input images. For gain $\ensuremath{\simeq}2.5$, measured noise-figure values ( $0.2\ifmmode\pm\else\textpm\fi{}0.6$) and $0.4\ifmmode\pm\else\textpm\fi{}0.5$) dB, respectively, two amplifiers different lengths. These experimental agree with theory (for an ideal noise figure is 0 dB) are almost 2 dB lower than quantum limit...
We study the purity of correlated photon pairs generated in a dispersion-shifted fiber at various temperatures. The ratio coincidence to accidental-coincidence counts greater than 100 can be obtained as is cooled liquid-nitrogen temperature (77 K). then generate polarization-entangled by using compact counterpropagating scheme. Two-photon interference with visibility >98% and Bell's inequality violation >8 standard deviations measurement uncertainty are observed 77 K, without subtracting due...
Degenerate four-wave mixing has been suggested as a possible generation scheme for squeezed-state light. A recent analysis of the quantum effects probe-conjugate loss in backward degenerate shown that such puts an absolute limit on squeezing can be obtained via this scheme. In Rapid Communication we show it is counter-propagating beam geometry makes ill suited generation. On other hand, nominally copropagating forward to alleviate squeezing.