An optical model with a hyperbola-parabola primary mirror added in the Cassegrain antenna, which can effectively improve transmission efficiency, is proposed this paper. The optimum parameters of and secondary for antenna system have been designed analyzed detail. parabola-hyperbola structure obtained to efficiency 10.60% theory, simulation changed 9.359%. For different deflection angles receiving emit coupling curve has obtained.

With the help of vector theory reflection and refraction, a novel emitting Cassegrain antenna with semitransparent secondary mirror has been proposed analyzed for distant point source. Based on absorptivity valued at 3.00% reflectivity 0.10%, this new can increase transmission efficiency from 63.65% to 93.85%. In addition, an off-axis parabolic receiving corresponding is designed 3D ray-trace simulation result given. According result, nicely converge rays antenna.

Central energy loss is a critical factor decreasing the transmission efficiency of Cassegrain antenna. In this paper, pair conic lenses are designed and set in front antenna to improve instead designing complicated structure. On basis analysis, optimized lens can theoretically up 100% at wavelength 1550 nm under ideal conditions. After several practical factors considered, such as dispersion material, transmissivity chamfering lens, reflectivity mirrors composing antenna, still increase...

In this paper, the propagation properties of Laguerre-Gaussian (LG) beam passing through Cassegrain antenna system in a turbulent atmosphere have been researched. The accurate analytical function for diffraction field LG antenna, average intensity, and cross-talk among different orbital angular momentum (OAM) modes Kolmogorov derived. simulation results show that with ring-like distribution is selected to enhance emission efficiency antenna. OAM can remarkably reduce using analysis process...

In this paper, an asymmetric large-mode-area photonic crystal fiber (LMA-PCF) with low bending loss at a smaller radius is designed. The finite-element method perfectly matched layer boundary used to analyze the performance of PCF. To achieve LMA-PCF loss, air holes double lattice constants and different sizes core are Numerical results show that structure can LMA wavelength 1.55 μm. effective mode area fundamental larger than 1000 μm2 when ≥10 cm. just 0.0113 dB/m, difference between...

We propose a novel annular focus antenna with an off-axial parabolic primary mirror and slanting hyperbolic secondary mirror. Ray tracing based on three-dimensional vector reflection theory is utilized to design analyze the structural parameters of antenna. In ideal conditions, there no geometric loss in transmitting efficiency increases by 24.54% compared conventional Cassegrain optical The also calculated conditions on-axial defocus. simulated results demonstrate that this can increase...

In this work, a novel design of high birefringence photonic crystal fiber (HB-PCF) with multimode and low confinement loss is proposed. To achieve birefringence, the core designed as an elliptical region, which enclosed by twelve small holes. Based on design, replacing two circular holes at top bottom region can further improve birefringence. At wavelength 1.55 μm, fundamental mode (LP01) second-order (LP11) are 1.70×10-2 1.85×10-2, respectively. Meanwhile, losses maintain orders 1×10-5...

To solve the serious loss problem for central energy of Cassegrain antenna, this paper designs a beam-shaping system, named E-A to convert elliptical divergent beam with astigmatism from laser diode into an annular collimation beam. This comprised only lenses quadratic surfaces, can simultaneously realize four functions, i.e., aberration correction, circularization, collimation, and dark hollow generation. By adjusting parameters, system be used shape astigmatic beams different parameters....

With the improvement of transmission efficiency, Cassegrain antenna can be widely used in space optical communication. In this paper, Bessel-Gaussian (BG) beam is to avoid central energy loss a system. The intensity distribution and phase BG passing through are theoretically derived simulated. At wavelength 1550 nm, method improve efficiency approach 100% under situation which obscuration ratio nonzero, reach more than 80% when range from 0 0.1252 with $l=4$l=4. effects on-axial defocusing...

With the development of digital holography, accuracy requirements for reconstruction phase are becoming increasingly high. The transfer function double fast transform (D-FFT) algorithm is distorted when diffraction distance larger than criterion dt, which reduces solving phase. In this paper, Fresnel integration improved by using low-pass Tukey window to obtain more accurate reconstructed phases. called D-FFT (Tukey) algorithm. adjusts degree edge smoothing window, peak signal-to-noise ratio...

Abstract Hybrid nanostructures with a plasmonic core and catalytic shell often show significantly enhanced efficiency under illumination of specific frequency. Excitation localized surface resonance on metals can generate hot electrons that assist in the reaction. However, correlation between microstructural geometry, dielectric environment, internal energy flow hybrid structure, chemical reaction rate is so far not clear. Here, composite Au metal yolk nearly transparent Ni 3 S 2 designed to...

In this paper, a reflector antenna design method is proposed to improve transmission efficiency and control output intensity distribution. Primary secondary mirrors are constructed segment by using numerical according the law of energy conservation, vector theory reflection, Fermat's principle that optical path length each ray must be equal. To verify effectiveness practicability method, an example with prescribed distribution beam given. The system designed reaches 100% in theory. effects...

• The 2-D and 3-D ray tracing of the parallel beam passing through Cassegrain antenna. Propagation properties in free space turbulence atmosphere are researched. Focusing property BG collimating optical system. focusing can potentially reduce cross-talk among different OAM modes. transmission characteristics Bessel-Gaussian (BG) propagation after antenna system researched this paper. research results show that half-cone angles parameters be used to control trajectory orbital angular momentum...

The low efficiency of coupling a hollow Gaussian beam into single-mode fiber terribly decreases the transmission an optical communication system. In this paper, system containing shaping lens and is designed based on vector theory refraction. simulation results show that our can improve to 81.45%, still reach 74.73% even though chamfering other factors are considered. This paper may not only provide engineers with more efficient but also designers ideas hollow-solid (or solid-hollow) systems.

Designing a cavity with high quality factor for omnidirectionally emitting laser (OEL) can extend its potential applications in optical communication and biomedical detection. We demonstrate method including five steps to design high-Q OEL using one-dimensional topological photonic crystal heterostructure. A Si/SiO2 fiber solid gain medium Er-doped SiO2 is designed following our steps. The axially transmit the pump energy at low confine loss act as radial emission of exited beam,...

The ray transfer matrix method is widely used for analyzing beam-transmission properties and designing multi-pass systems. In this paper, a modified proposed tracing an accurate non-sequential in three-dimensional space based on vector reflection theory. can be utilized to analyze transmitting between arbitrary surfaces, which not confined rotational symmetrical structures. There no need project rays onto two perpendicular planes, nor introduce paraxial approximation our calculation. Since...