Subjects: Optics >> Ultrafast optics submitted time 2024-01-31
LIU Junkai
DENG Xuan
YANG Kaizhi
LUO Qiuyan
NIU Lihong
ZHANG Jingjin
LIU Jinyuan
CAI Houzhi
XIANG Lijuan
Abstract： The original 3D image, denoted as I(x-y-t), is encoded and modulated using digital micromirror devices (DMD), subsequently transmitted to a slit full-open fringe image converter. By means of deflection via a deflecting electric field, multiple images at various time points are superimposed, resulting in the generation of the final integral image on the CCD. To reconstruct multiple original images I(x-y-t) from the CCD integral images, a total variational restoration algorithm is employed. In this study, we simulate the process of image acquisition and the restoration algorithm within the compressed ultrafast imaging system. As a result, we obtain eight dynamic 2D images depicting laser transmission through an air medium. Each image is exposed for a duration of 12.5 ps, and the reconstructed signal demonstrates a similarity of 0.92 when compared to the original signal.
Subjects: Optics >> Microscopy submitted time 2023-11-15
Abstract： A full-field transmission hard X-ray microscope (TXM) with 30nm resolution was designed and its prototype was constructed. The TXM relies on a compact, high stiffness, low heat dissipation and low vibration design philosophy and utilizes Fresnel Zone plate (FZP) as imaging optics. The design of the TXM was introduced in detail, including the optical layout, the parameters of the FZP, the mechanical design of the TXM instrument. Preliminary imaging result with 52nm spatial resolution was achieved.
Subjects: Optics >> Quantum optics submitted time 2023-07-10
Abstract： The atomic system has reflection symmetry, parity, and atomic stimulated radiation amplified by a parallel plane resonant cavity, can generate macroscopic photons entangled state[4].
It is a quantum entangled state of 2N photons with a certain parity, a total momentum of zero, a certain energy, and a certain angular momentum. Observing it in time and space has uncertainty and randomness. According to the Heisenberg uncertainty principle, its energy (frequency) and momentum are completely determined. The measurement accuracy can reach the Heisenberg quantum limit and has a quantum 2N enhancement effect (2N is the number of entangled photons).
The probability distribution P2N （t） of ∣Ф2NI > and its fourier transform P2N （w-w0 ）were measured through experiments, and the experimental results were in line with theoretical expectations. And the lifetime of macroscopic photons entangled state was observed, which also has a 2N enhancement factor. The experimental results are consistent with theoretical expectations.
Peer Review Status:
Awaiting Review
Subjects: Astronomy >> Astronomical Instruments and Techniques Subjects: Optics >> Instrumentation, measurement, and metrology Subjects: Optics >> Coherence and statistical optics submitted time 2023-06-28
Abstract： Co-phase and co-focus detection is one of the key technologies for large-aperture segmented mirror telescopes. In this paper, a new edge sensor based on fringes of equal thickness is developed, which can detect each segment's relative piston, tilt, and tip errors from the interferograms. Based on the co-focus demand for many ground-based seeing limited segmented mirror telescopes, an edge sensor prototype based on such a principle is built and applied in the indoor segmented mirror experiment system in the lab. According to the co-focus requirement of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, many simulations and experiments are carried out for co-focus error detection of the segmented mirror system. Experiment results show that the co-focus accuracy is better than 0."02 rms, which can meet the co-focus requirements of most large or extremely large segmented mirror astronomical telescopes.
Subjects: Optics >> Quantum optics submitted time 2023-06-25
Abstract： Multi-photon entanglement is the core technology of quantum information technology such as quantum computation and quantum communication. Two-photon entanglement generated by spontaneous parametric down-conversion is a commonly used source of entanglement. Entangled photons emit randomly, and the probability of entanglement pairs is very small. Although great achievements have been made, it is still far from the application requirements of quantum computing and other fields. New approaches need to be explored from two aspects of basic theory and experimental research.
In this paper, the fundamental process of stimulated radiation and the mechanism of stimulated radiation are studied. It is found that the quantum properties of the initial two-photon state produced by this process are closely related to the symmetry of the stimulated substances. If the electronic states of stimulated radiation substances have parity, their wave functions also have parity, such as atoms, molecules with symmetric centers, crystals with reflection symmetry, etc. The electronic states of these substances have parity and reflection symmetry. The stimulated radiation process of a parity substances obeys parity conservation. The two-photon state produced by the stimulated radiation has parity and is superposition entangled state. Such two entangled photons pass through the action of parallel plane resonator, and then through stimulated radiation, the process is repeated again and again, and finally produces multi-photon entanglement.
The main results and conclusions of this paper are as follows: multi-photon entangled state is generated by stimulated radiation of parity substances. If the electronic state of the laser substance has parity, the multi-photon state produced by the stimulated radiation in the laser resonator (parallel plane cavity) is entangled state and can be output from a symmetrical two-way single longitudinal mode laser.
The expression of multiphoton entanglement is given theoretically. A symmetrical bi-directional output single longitudinal mode He-Ne laser has been developed. The experimental verification of multi-photon entangled state has been carried out. The experimental results are in good agreement with the theoretical expectations.
Peer Review Status:Awaiting Review
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