Generation of squeezed vacuum on cesium D2 line down to kilohertz range

We study the influence of driving ways on the interaction in a two-atoms cavity quantum electrodynamics system. The results show that driving ways can induce different excitation pathways. We show two kinds of significantly different excitation spectrums under two ways: driving cavity and driving atoms. We demonstrate that driving atoms can be considered as a method to obtain the position information of atoms. This research has very practical application values on obtaining the position information of atoms in a cavity.

Section: Introductionmentioning

confidence: 99%

Influence of driving ways on measurement of relative phase in a two-atoms cavity system*

Bao¹,

Xu²,

Yang³

2020

“…[13] So far there have been more and more methods to generate squeezed light, nevertheless the parametric down-conversion process has been proved to be the most effective way to prepare the squeezed light. [14][15][16][17][18][19] Because the squeezed lights were generated from nonlinear optics in the past, they all have macro intensity. The development of quantum communication and quantum computing requires the light field to reach the single photon level.…”

Section: Introductionmentioning

confidence: 99%

Preparation of squeezed light with low average photon number based on dynamic Casimir effect

Li 李,

Lin 林,

Wei 韦

et al. 2023

It is well known that squeezed states can be produced by nonlinear optical processes, such as parametric amplification and four wave mixing, in which two photons are created or annihilated simultaneously. Since the Hamiltonian of the dynamic Casimir effect contains a 2 and a +2, photons in such process are also generated or annihilated in pairs. In this paper, we propose to get squeezed light through the dynamic Casimir effect, in detail, we demonstrate it from the full quantum perspective and the semiclassical perspective successively. Different from previous work, we focus on generating squeezed states with the lowest average photon number, because such squeezed states have better quantum properties. For the full quantum picture, that is, phonons also have quantum properties. When the system is initially in the excited state of phonons, squeezed light cannot be generated during the evolution, but the light field can collapse to the squeezed state by measuring the state of phonons. When the phonon is treated as a classical quantity, that is, the cavity wall is continuously driven, squeezed light with the minimum average photon number will be generated in the case of off-resonance. This will play a positive role in better regulating the photon state generated by the dynamic Casimir system in the future.

“…[6][7][8][9][10] While the bright squeezed state has a coherent amplitude, which can be used in spectroscopic measurement, [11,12] velocimetry, [13] LIDAR, [14] and quantum key distribution. [15,16] The detection, [17,18] besides the generation [19][20][21][22] and propagation of squeezed states, is another key element for improving their application performances. Many dedicated researches have been carried out to explore a balanced homodyne detector (BHD) with low-noise, high-gain, and high common mode rejection ratio (CMRR).…”

Section: Introductionmentioning

confidence: 99%

A low-noise, high-SNR balanced homodyne detector for the bright squeezed state measurement in 1–100 kHz range*

Wang

Liang

et al. 2020

We report a low-noise, high-signal-to-noise-ratio (SNR) balanced homodyne detector based on the standard transimpedance amplifier circuit and the inductance and capacitance combination for the measurement of the bright squeezed state in the range from 1 kHz to 100 kHz. A capacitance is mounted at the input end of the AC branch to prevent the DC photocurrent from entering the AC branch and avoid AC branch saturation. By adding a switch at the DC branch, the DC branch can be flexibly turned on and off on different occasions. When the switch is on, the DC output provides a monitor signal for laser beam alignment. When the switch is off, the electronic noise of the AC branch is greatly reduced at audio-frequency band due to immunity to the impedance of the DC branch, hence the SNR of the AC branch is significantly improved. As a result, the electronic noise of the AC branch is close to −125 dBm, and the maximum SNR of the AC branch is 48 dB with the incident power of 8 mW in the range from 1 kHz to 100 kHz. The developed photodetector paves a path for measuring the bright squeezed state at audio-frequency band.