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Junhui Li

Publications and source records attributed to Junhui Li.

77 records · Page 5Linked to original sources

Source coding model for repeated snapshot imaging

Imaging based on successive repeated snapshot measurement is modeled as a source coding process in information theory. The necessary number of measurement to maintain a certain level of error rate is depicted as the rate-distortion function of the source coding. Quantitative formula of the error rate versus measurement number relation is derived, based on the information capacity of imaging system. Second order fluctuation correlation imaging (SFCI) experiment with pseudo-thermal light verifies this formula, which paves the way for introducing information theory into the study of ghost imaging (GI), both conventional and computational.

physics.optics↗

Modeling the behavior of signal-to-noise ratio for repeated snapshot imaging

For imaging of static object by the means of sequential repeated independent measurements, a theoretical modeling of the behavior of signal-to-noise ratio (SNR) with varying number of measurement is developed, based on the information capacity of optical imaging systems. Experimental veritification of imaging using pseudo-thermal light source is implemented, for both the direct average of multiple measurements, and the image reconstructed by second order fluctuation correlation (SFC) which is closely related to ghost imaging. Successful curve fitting of data measured under different conditions verifies the model.

physics.optics↗

Integrated Surface-enhanced Raman Spectroscopy chip based on liquid core waveguide

We propose an integrated surface enhanced Raman scattering (SERS) chip based on liquid-core waveguide with total reflection, through which the depression of leaky mode enable a long propagating distance. An Raman enhancement factor for rhodamine 6G of 2.5*105 is obtained, and a excellent repeatability is shown. The peaks in the SERS spectrum of DNA of silkworm clearly illustrate the information of the molecule structure. The integration of the SERS substrate, micro-fluid, and liquid-core waveguide make such a SERS chip attractive for biochemical detection with high performance.

physics.optics↗

Quantum resource studied from the perspective of quantum state superposition

Quantum resources,such as discord and entanglement, are crucial in quantum information processing. In this paper, quantum resources are studied from the aspect of quantum state superposition. We define the local superposition (LS) as the superposition between basis of single part, and nonlocal superposition (NLS) as the superposition between product basis of multiple parts. For quantum resource with nonzero LS, quantum operation must be introduced to prepare it, and for quantum resource with nonzero NLS, nonlocal quantum operation must be introduced to prepare it. We prove that LS vanishes if and only if the state is classical and NLS vanishes if and only if the state is separable. From this superposition aspect, quantum resources are categorized as superpositions existing in different parts. These results are helpful to study quantum resources from a unified frame.

quant-ph↗