Quantum optics of soliton microcombs Guidry, Melissa A.; Lukin, Daniil M.; Yang, Ki Youl ...
Nature photonics,
01/2022, Letnik:
16, Številka:
1
Journal Article
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Soliton microcombs—phase-locked microcavity frequency combs—have become the foundation of several classical technologies in integrated photonics, including spectroscopy, LiDAR and optical computing. ...Despite the predicted multimode entanglement across the comb, experimental study of the quantum optics of the soliton microcomb has been elusive. In this work we use second-order photon correlations to study the underlying quantum processes of soliton microcombs in an integrated silicon carbide microresonator. We show that a stable temporal lattice of solitons can isolate a multimode below-threshold Gaussian state from any admixture of coherent light, and predict that all-to-all entanglement can be realized for the state. Our work opens a pathway toward a soliton-based multimode quantum resource.The quantum aspect of soliton microcomb from an integrated silicon carbide microresonator is studied in several regimes — below threshold, above threshold and in the soliton regime — using a single-photon optical spectrum analyser for second-order photon correlation measurement.
Abstract Radar display console is an equipment which is closely associated with people as a medium of human-computer interaction. However, for the sake of heat dissipation, draught fans in display ...console make continuous noise when radar is on operation, the noise dose harm to human health. In order to reduce the noise, an impedance compound muffler is designed in this paper, and then the acoustic characteristics of muffler is studied by simulation method. In the end, the simulation results are verified by means of noise spectrum analyser, as a result, the muffler obtains good silencing effect and the maximum sound level of the radar display console is reduced by 3dB.
Wireless communication systems using millimeter-wave (mmWave) frequencies can be used for high-throughput applications such as fixed wireless access, where static line-of-sight links are used to ...provide internet connectivity. The directive antennas are typically mounted on building facades above street level. Therefore, the wireless links are mainly subject to attenuation due to atmospheric absorption, rain, and vegetation. In this letter, we present vegetation loss measurements at Formula Omitted-band frequencies ranging from 50 to 75 GHz, using a spectrum analyzer-based channel sounder. Existing vegetation models, including the vegetation-dependent exponential decay (VED) model, are validated based on the measured vegetation loss. Furthermore, IEEE 802.11ad transceivers are used for the validation of the vegetation models, and to evaluate the influence of vegetation on the network performance via packet error rate (PER) and throughput measurements.
The color of oranges originates from carotenoids, which are natural pigments ranging from yellow to red color and is indicative of the sugar level and degree of ripeness. During the degreening ...process, the fruit quality can deteriorate, which is manifested as insufficient ripeness and sugar (sucrose) content. Therefore, in this study, we have designed a low-cost, easy-to-use optoelectronic system to measure the sugar content in orange and lemon juice. The system consists of a U-shaped plastic optical fiber (POF) and a visible multispectral sensor. The device identifies variation in the absorption of the evanescent field of the POF when it comes in contact with orange juice. The response of the multispectral sensor in the wavelength range of 450–650 nm is digitally captured, improving the efficiency and accuracy of the measurements. To validate the multispectral sensor measurements, the sugar contents are compared with those obtained using a visible spectrum analyzer and refractometer.
Abstract
Measurement of temperature changes is very important in the fields of physics, chemistry, biology, and industrial applications. The development of temperature sensors also continues to be ...developed both on an electric and optical basis. In this research, the detection of temperature changes based on optics is successfully detected using optical fiber splitter 1 × 2 by utilizing a plane mirror as a reflector and by stripping the cladding at the end optical fiber. Measurement of the power transmission of reflection to changes in temperature using an optical spectrum analyzer (OSA) at wavelength 1550 nm. This research showed that a linear relationship between transmission power and temperature increase from 40°C to 200°C on the sensor probe with a stripping length of 35 mm.
Characterization and suppression of noise are essential for the control of harmonic oscillators in the quantum regime. We measure the noise spectrum of a quantum harmonic oscillator from low ...frequency to near the oscillator resonance by sensing its response to amplitude modulated periodic drives with a qubit. Using the motion of a trapped ion, we experimentally demonstrate two different implementations with combined sensitivity to noise from 500 Hz to 600 kHz. We apply our method to measure the intrinsic noise spectrum of an ion trap potential in a previously unaccessed frequency range.
Radio frequency sources heavily impact human life due to the high number of technologies exploiting them. Their level assessment is a complex task because of differences in technologies working ...principles and high growth rate. Among them, cellular communications are the most pervasive, and several concerns are often addressed to currently deploying 5G. Here, 4G long-term evolution (LTE) technology is focused because it is still the largest used communication facility. To assess human exposure due to LTE, apart from traditional broadband and narrowband methods, easier and faster approaches have been proposed in the literature and the most recent technical standards: the extrapolation techniques (ETs). They measure pilot signals' levels and process them to obtain the equivalent worst case channel power. They are designed to overestimate the current channel power by estimating the maximum channel power in the measurement point, thus warranting a conservative approach. Nevertheless, some of the needed hypotheses, such as the pilot signal power constancy, do not always pass the experimental validation. Based on that, in some cases, supposed overestimation can turn into underestimation, thus losing the "conservative" feature and making the power measurement unreliable. Through a wide experimental analysis, this article aims to highlight those issues and derive an improved measurement procedure, under the assumption that a basic spectrum analyzer is adopted as a measuring instrument.
In this communication, an echo suppression method is presented to recover the true antenna gain pattern measured in a nonanechoic environment based on phaseless measurement data. With the proposed ...technique, the antenna pattern convoluted with the multipath spatial profile can be extracted with a deconvolution operation based on the scalar frequency response measurement, which can be easily obtained with a spectrum analyzer. The proposed scheme is advantageous compared to complex-signal-based methods since it is a phaseless solution. Moreover, a generalized solution jointly exploiting the frequency (i.e., using wideband scalar frequency response measurement) and spatial (i.e., using several spatial samples) domain is proposed to further improve the pattern reconstruction accuracy, where the state-of-the-art spatial-domain and the proposed frequency-domain solutions can be seen as special cases. Numerical simulations as well as experimental measurement results demonstrated the feasibility and advantages of the proposed algorithm.
Detection of biomarkers associated with wound conditions provides in‐depth healthcare information and benefits wound healing treatment. The current aim of wound detection is to achieve in situ ...multiple detections. Novel encoded structural color microneedle patches (EMNs) combining photonic crystals (PhCs) and microneedle arrays (MNs) for multiple wound biomarker detection in situ are described here. Using a partitioned and layered casting strategy, the EMNs can be divided into different modules and each serves for the detection of small molecules , including pH, glucose, and histamine. pH sensing is based on the interaction between hydrogen ions and carboxyl groups from hydrolyzed polyacrylamide (PAM); glucose sensing is achieved with the help of glucose‐responsive fluorophenylboronic acid (FPBA); while histamine sensing relies on specific recognition of aptamers and target molecules. Owing to the responsive volume change of these three modules in the presence of target molecules, the EMNs can create structural color change and characteristic peak shift of the PhCs, thus realizing the qualitative measurement of target molecules with a spectrum analyzer. It is further demonstrated that the EMNs behave well in the multivariate detection of rat wound molecules. These features indicate that the EMNs can be valuable smart detection systems for wound status screening.
Detection of biomarkers associated with wound conditions provides in‐depth healthcare information and benefits wound healing treatment. The current aim of wound detection is to achieve in situ multiple detections. Novel encoded structural color microneedle patches combining photonic crystals and microneedle arrays for multiple wound biomarker detection in situ are described here.
There are several issues that present in conventional sensor including its accuracy, safety, durability and RF effect. These issues could be minimized with the implementation of fiber optic sensor. ...This project is to design and implement optical sensor using FBG for various temperature and liquid density sensing. The FBG sensor was submerged in liquid substances to determine the sensing conditions. The available pigtail was connected to the circulator, 1550nm laser source and optical spectrum analyzer (OSA). The data regarding temperature and density sensing captured from OSA were observed and analyzed. It is found that the relationship between the change in temperature and the change in wavelength is virtually linear in both environments making FBG a good candidate for sensing temperature.
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