Recent methodology advances in fluorescence molecular tomography

Molecular imaging(MI)is a novel imaging discipline that has been continuously developed in recent years.It combines biochemistry,multimodal imaging,biomathematics,bioinformatics,cell&molecular physiology,biophysics,and pharmacology,and it provides a new technology platform for the early diagnosis and quantitative analysis of diseases,treatment monitoring and evaluation,and the development of comprehensive physiology.Fluorescence Molecular Tomography(FMT)is a type of optical imaging modality in MI that captures the three-dimensional distribution of fluorescence within a biological tissue generated by a specific molecule of fluorescent material within a biological tissue.Compared with other optical molecular imaging methods,FMT has the characteristics of high sensitivity,low cost,and safety and reliability.It has become the research frontier and research hotspot of optical molecular imaging technology.This paper took an overview of the recent methodology advances in FMT,mainly focused on the photon propagation model of FMT based on the radiative transfer equation(RTE),and the reconstruction problem solution consist of forward problem and inverse problem.We introduce the detailed technologies utilized in reconstruction of FMT.Finally,the challenges in FMT were discussed.This survey aims at summarizing current research hotspots in methodology of FMT,fromwhich future research may benefit.

Bessel–Gauss photon beams with fractional order vortex propagation in weak non-Kolmogorov turbulence

We model the effects of weak fluctuations on the probability densities and normalized powers of vortex models for the Bessel–Gauss photon beam with fractional topological charge in the paraxial non-Kolmogorov turbulence channel. We find that probability density of signal vortex models is a function of deviation from the center of the photon beam, and the farther away from the beam center it is, the smaller the probability density is. For fractional topological charge, the average probability densities of signal/crosstalk vortex modes oscillate along the beam radius except the half-integer order. As the beam waist of the photon source grows, the average probability density of signal and crosstalk vortex modes grow together. Moreover, the peak of the average probability density of crosstalk vortex modes shifts outward from the beam center as the beam waist gets larger. The results also show that the smaller index of non-Kolmogorov turbulence and the smaller generalized refractive-index structure parameter may lead to the higher average probability densities of signal vortex modes and lower average probability densities of crosstalk vortex modes. Lower-coherence radius or beam waist can give rise to less reduction of the normalized powers of the signal vortex modes, which is opposite to the normalized powers of crosstalk vortex modes.

Quantum information transfer between photonic and quantum-dot spin qubits

We propose schemes for the efficient information transfer between a propagating photon and a quantum-dot（QD） spin qubit in an optical microcavity that have no auxiliary particles required. With these methods, the information transfer between two photons or two QD spins can also be achieved. All of our proposals can work with high fidelity, even with a high leakage rate. What is more, each information transfer process above can also be seen as a controlled-NOT（CNOT） operation. It is found that the information transfer can be equivalent to a CNOT gate. These proposals will promote more efficient quantum information networks and quantum computation.