Subjects: Optics >> Optical design and fabrication submitted time 2022-10-19 Cooperative journals: 《桂林电子科技大学学报》
Abstract： In order to better choose a suitable auxiliary objective lens, this article is based on the working principle of the
auxiliary objective lens, starting from both theoretical deduction and experimental simulation, firstly, the structure optimization
design of the common double glued auxiliary objective lens is carried out. According to the design requirements, the
initial structure of the auxiliary objective lens was reasonably selected, and various aberrations were theoretically deduced.
Finally, based on the initial structure and optimization goals, the optical design software OSLO is used to optimize the structure
and aberration analysis of the two forms of auxiliary objective lenses. Afterwards, the design of the innovative double
cemented-thick meniscus auxiliary objective lens was optimized. The structural parameters of the similar lens in the literature
were used as the initial structure of the design. OSLO optical software and design experience were used to optimize the
structure and analyze aberrations. And correction. Finally, the two types of auxiliary objectives are compared and analyzed.
The results show that the parameters of the two types of auxiliary objectives after optimization can meet the design requirements,
but the double-bonded-thick meniscus type auxiliary objective is more suitable for large images. The optical system
of the surface.
Subjects: Optics >> Quantum optics submitted time 2023-02-19
Abstract： High harmonic generation (HHG) from crystals in strong laser fields has been understood by the band theory of solid, which is based on the periodic boundary condition (PBC) of translational invariant. For systems having PBC of rotational invariant, in principles an analogous Bloch theorem can be developed and applied. Taking a ring-type cluster of cyclo[18]carbon as a representative, we theoretically suggest a quasi-band model and study its HHG by solving time-dependent Liouville-von Neumann equation. Under the irradiation of circularly polarized laser, explicit selection rules for left-handed and right-handed harmonics are observed, while in linearly polarized laser field, cyclo[18]carbon exhibits solid-like HHG originated from intra-band oscillations and inter-band transitions, which in turn is promising to optically detect the symmetry and geometry of controversial structures. In a sense, this work presents a connection linking the high harmonics of gases and solids.
Peer Review Status:
Awaiting Review
Subjects: Optics >> Quantum optics submitted time 2023-02-19
Abstract： This paper proposes a novel and rapid calibration-free wavelength modulation spectroscopy algorithm based on even-order harmonics. The proposed algorithm, analytically deduced from Voigt line-shape function, only involves simple algebraic operations to describe the actual gas absorption spectra, thus eliminating the time-consuming simulations and line-shape fitting procedures adopted in traditional algorithms. Instead of acquiring the entirely scanned absorption line-shape, the proposed technique only requires extraction of the peak values of the harmonics. This characteristic significantly benefits gas diagnosis at elevated pressure and/or temperature, in which the entirely scanned absorption is very difficult to be obtained due to the broadened line-shapes. The proposed algorithm is validated by both numerical simulation and condition-controlled experiment, indicating millisecond-level calculation of gas parameters with the relative error less than 4% in the experiments.
Peer Review Status:Awaiting Review
Subjects: Optics >> Quantum optics submitted time 2023-02-19
Abstract： Applicability and accuracy of traditional scanned-wavelength direct absorption spectroscopy (SDAS) diagnostic method is largely affected by combustion state such as temperature and pressure. To resolve this problem, an innovative baseline-free scanned-wavelength direct absorption spectroscopy (BF-SDAS) method is proposed in this work. This method does not need the zero-absorption regions for baseline fitting and can exclude the influence of baseline fitting error on the final result. It is especially suitable for the cases when the scanning range is too narrow or the absorption linewidth is too large to acquire the baseline. In this paper, the BF-SDAS is first derived and theoretically analyzed based on the Fourier analysis, and then the accuracy of this method is validated by measuring the concentration of H2O molecules in a static gas absorption cell at room temperature.
Peer Review Status:Awaiting Review
Subjects: Optics >> Quantum optics submitted time 2023-02-19
Abstract： Multiplexing multiple orbital angular momentum (OAM) modes of light has the potential to increase data capacity in optical communication. However, the distribution of such modes over long distances remains challenging. Free-space transmission is strongly influenced by atmospheric turbulence and light scattering, while the wave distortion induced by the mode dispersion in fibers disables OAM demultiplexing in fiber-optic communications. Here, a deep-learning-based approach is developed to recover the data from scattered OAM channels without measuring any phase information. Over a 1-km-long standard multimode fiber, the method is able to identify different OAM modes with an accuracy of more than 99.9% in parallel demultiplexing of 24 scattered OAM channels. To demonstrate the transmission quality, color images are encoded in multiplexed twisted light and our method achieves decoding the transmitted data with an error rate of 0.13%. Our work shows the artificial intelligence algorithm could benefit the use of OAM multiplexing in commercial fiber networks and high-performance optical communication in turbulent environments.
Peer Review Status:Awaiting Review
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