With a levitodynamics experiment in the strong and coherent quantum optomechanical coupling regime, we demonstrate that the oscillator acts as a broadband quantum spectrum analyzer. The asymmetry ...between positive and negative frequency branches in the displacement spectrum traces out the spectral features of the quantum fluctuations in the cavity field, which are thus explored over a wide spectral range. Moreover, in our two-dimensional mechanical system the quantum backaction, generated by such vacuum fluctuations, is strongly suppressed in a narrow spectral region due to a destructive interference in the overall susceptibility.
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.
Abstract
Resolution Band Width (RBW) represents the 3 dB bandwidth of the internal IF filter of the spectrum analyzer, the setting of which greatly affects the clarity of the output spectrum line of ...the spectrum analyzer. Its reasonable value is essential to correctly distinguish the signals of different frequencies, especially in the case of aliasing of the output spectrum. Thus, it is of great significance to study the relationship between the setting of RBW and the output spectrum. Due to the expensive spectrum analyzer, the RBW adjustment range, frequency range and output accuracy are limited, so this paper will apply an economic, RBW arbitrary adjustable, high accuracy equivalent convolution method for the simulation of the RBW parameters of the spectrum analyzer, and evaluate the effect of RBW and filter type on the degree of output spectrum aliasing based on a typical equal-amplitude two-tone signal input, and finally give setting suggestions on RBW and filter type.
Quantum optics of soliton microcombs Guidry, Melissa A.; Lukin, Daniil M.; Yang, Ki Youl ...
Nature photonics,
01/2022, Letnik:
16, Številka:
1
Journal Article, Paper
Recenzirano
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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.
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.
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.
Abstract
The C band microwave signals are widely used for Earth observation in the field of remote sensing by using synthetic aperture radar sensor. The coverage of Indian regions by Sentinel 1A SAR ...sensor in interoferometric wide swath mode, provide an opportunity to research and conduct studies in remote sensing areas from urban planning to disaster management applications. The sensor acquired images undergo calibration test to confirm the quality requirements. The foremost significant step to ensure the availability of the signal of Sentinel 1A on the ground surface is by designing a antenna system which tracks and monitor the signal strength. In this context, the following stages are significant in signal monitoring system: satellite downlink budget calculation to ensure minimum signal strength, designing and configuring antenna system to receive the signals and measurement system such as spectrum analyser to monitor the signal strength. The paper presents the mathematical analysis of designing a down link for receiving Sentinel-1A SAR signals. An antenna subsystem is implemented which includes the design of the parabola antenna with horn feed and the simulation of the same using Matlab platform to confirm antenna parameters such as gain, directivity, VSWR and beam-width which meets the practical requirements
The technological progress in the means of transmission of information is very fast and it became necessary to obtain high speed in data transmission and high rate of data. Therefore, optical ...communication systems are the leading methods in this field because they cover these needs, but despite all these characteristics, there is a problem, And we will get rid of this problem in practice in this research through the use of two separate and different wavelengths and connect them to the Wavelength Division Multiplexing and send them to a distance of 3 Km and calculate the amount of dispersion in the signal to the outside of the Optical spectrum analyzer with and without Optical Fiber Bragg Gratings.
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.
Phase-sensitive detection is the essential projective measurement for measurement-based continuous-variable quantum information processing. The bandwidth of conventional electrical phase-sensitive ...detectors is up to several gigahertz, which would limit the speed of quantum computation. It is theoretically proposed to realize terahertz-order detection bandwidth by using all-optical phase-sensitive detection with an optical parametric amplifier (OPA). However, there have been experimental obstacles to achieve large parametric gain for continuous waves, which is required for use in quantum computation. Here, we adopt a fiber-coupled \(\chi^{(2)}\) OPA made of a periodically poled LiNbO\({}_{3}\) waveguide with high durability for intense continuous-wave pump light. Thanks to that, we manage to detect quadrature amplitudes of broadband continuous-wave squeezed light. 3 dB of squeezing is measured up to 3 THz of sideband frequency with an optical spectrum analyzer. Furthermore, we demonstrate the phase-locking and dispersion compensation of the broadband continuous-wave squeezed light, so that the phase of the squeezed light is maintained over 1 THz. The ultra-broadband continuous-wave detection method and dispersion compensation would help to realize all-optical quantum computation with over-THz clock frequency.
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