Star Simulator Base on Multiple LEDs, Optical Fiber and Integral Sphere

2014 ◽  
Vol 672-674 ◽  
pp. 2048-2051
Author(s):  
Xin Ji Gan ◽  
Yan Chen

In order to design a compact star simulator based on multiple LEDs, optical fibers, an integral sphere and tiny collimated optical systems are employed in the system. Firstly the system configuration block diagram of the star simulator is given in this paper. Then the luminous flux calculation of LED is calculated based on the optical system. Finally the principle of PWM control of LED is illustrated. The analysis shows that the simulated precision of star magnitude can achieve ±0.1m.

2021 ◽  
Vol 24 (02) ◽  
pp. 218-226
Author(s):  
L.F. Kupchenko ◽  
◽  
V.D. Karlov ◽  
A.S. Rybiak ◽  
О.А. Goorin ◽  
...  

The issues discussed in this paper provide for further development of studies in the sphere of imaging spectroscopy and laser vision. In terms of forming the information fields (radiation fields), the electro-optical systems are subdivided into the passive and active ones. Passive electro-optical systems use the information fields formed by natural radiation sources, whereas the active ones suggest using artificial sources. Comparative analysis of mathematical and physical issues of designing the electro-optical systems with dynamic spectral processing of optical radiation of the passive and active types has been performed. It has been shown that the controlled dynamic spectral processing of optical radiation can be implemented within the passive and active electro-optical systems on the basis of the same algorithm that represents operation of the optical processor performing the mathematical operation of dot product. The authors have developed the block diagram of an active electro-optical system with dynamic spectral processing. The algorithm for optimal detection of optical signals has been developed using basics of the signal detection theory. Mathematical modeling of target detection against an inhomogeneous background has been performed. It has been shown that the optimal dynamic spectral processing of optical radiation in active electro-optical system enables to separate the desired optical signal by suppressing the background signal.


Author(s):  
J T Fourie

The attempts at improvement of electron optical systems to date, have largely been directed towards the design aspect of magnetic lenses and towards the establishment of ideal lens combinations. In the present work the emphasis has been placed on the utilization of a unique three-dimensional crystal objective aperture within a standard electron optical system with the aim to reduce the spherical aberration without introducing diffraction effects. A brief summary of this work together with a description of results obtained recently, will be given.The concept of utilizing a crystal as aperture in an electron optical system was introduced by Fourie who employed a {111} crystal foil as a collector aperture, by mounting the sample directly on top of the foil and in intimate contact with the foil. In the present work the sample was mounted on the bottom of the foil so that the crystal would function as an objective or probe forming aperture. The transmission function of such a crystal aperture depends on the thickness, t, and the orientation of the foil. The expression for calculating the transmission function was derived by Hashimoto, Howie and Whelan on the basis of the electron equivalent of the Borrmann anomalous absorption effect in crystals. In Fig. 1 the functions for a g220 diffraction vector and t = 0.53 and 1.0 μm are shown. Here n= Θ‒ΘB, where Θ is the angle between the incident ray and the (hkl) planes, and ΘB is the Bragg angle.


2012 ◽  
Vol E95.B (8) ◽  
pp. 2638-2641 ◽  
Author(s):  
Makoto YAMADA ◽  
Akisumi TOMOE ◽  
Takahiro KINOSHITA ◽  
Osanori KOYAMA ◽  
Yutaka KATUYAMA ◽  
...  
Keyword(s):  

2021 ◽  
Vol 11 (7) ◽  
pp. 3254
Author(s):  
Marco Pisco ◽  
Francesco Galeotti

The realization of advanced optical fiber probes demands the integration of materials and structures on optical fibers with micro- and nanoscale definition. Although researchers often choose complex nanofabrication tools to implement their designs, the migration from proof-of-principle devices to mass production lab-on-fiber devices requires the development of sustainable and reliable technology for cost-effective production. To make it possible, continuous efforts are devoted to applying bottom-up nanofabrication based on self-assembly to decorate the optical fiber with highly ordered photonic structures. The main challenges still pertain to “order” attainment and the limited number of implementable geometries. In this review, we try to shed light on the importance of self-assembled ordered patterns for lab-on-fiber technology. After a brief presentation of the light manipulation possibilities concerned with ordered structures, and of the new prospects offered by aperiodically ordered structures, we briefly recall how the bottom-up approach can be applied to create ordered patterns on the optical fiber. Then, we present un-attempted methodologies, which can enlarge the set of achievable structures, and can potentially improve the yielding rate in finely ordered self-assembled optical fiber probes by eliminating undesired defects and increasing the order by post-processing treatments. Finally, we discuss the available tools to quantify the degree of order in the obtained photonic structures, by suggesting the use of key performance figures of merit in order to systematically evaluate to what extent the pattern is really “ordered”. We hope such a collection of articles and discussion herein could inspire new directions and hint at best practices to fully exploit the benefits inherent to self-organization phenomena leading to ordered systems.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mahmoud M. A. Eid ◽  
Ahmed Nabih Zaki Rashed ◽  

AbstractThis study presents high speed optical switching gain based Erbium doped fiber amplifier model. By using the proposed model the optical fiber loss can be minimized. The system is stabilized with the power budget of 25.875 mW a long 75 km as a length of optical fiber in this study can be verified. The modulation rate of 10 Gb/s can be upgrade up to reach 30 Gb/s. The suitable power for the optical transmitter is −2.440 dBm and NRZ modulation code is verified. The receiver sensitivity can be upgraded with the minimum bit error rate and max Q factor are 1.806 e−009 and 5.899.


Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 195
Author(s):  
Ziqian He ◽  
Kun Yin ◽  
Kuan-Hsu Fan-Chiang ◽  
Shin-Tson Wu

The Maxwellian view offers a promising approach to overcome the vergence-accommodation conflict in near-eye displays, however, its pinhole-like imaging naturally limits the eyebox size. Here, a liquid crystal polymer-based Dammann grating with evenly distributed energy among different diffraction orders is developed to enlarge the eyebox of Maxwellian view displays via pupil replication. In the experiment, a 3-by-3 Dammann grating is designed and fabricated, which exhibits good efficiency and high brightness uniformity. We further construct a proof-of-concept Maxwellian view display breadboard by inserting the Dammann grating into the optical system. The prototype successfully demonstrates the enlarged eyebox and full-color operation. Our work provides a promising route of eyebox expansion in Maxwellian view displays while maintaining full-color operation, simple system configuration, compactness, and lightweight.


Author(s):  
Yih-Tun Tseng ◽  
Jhong-Bin Huang ◽  
Che-Hsin Lin ◽  
Chin-Lung Chen ◽  
Wood-Hi Cheng

The GI (graded-index) POFs (Plastic optical fibers), which has been proven to reach distances as long as 1 km at 1.25 Gb/s has a relatively low numerical aperture . Therefore, the efficient coupling of GI POFs to the light source has become critical to the power budget in the system. Efficient coupling for a POFs system normally involves either a separate lens or the direct formation of the lens at the end of the fiber. Forming the lens-like structure directly on the fiber end is preferred for simplicity of fabrication and packaging, such as polishing and fusion, combine different fibers with the cascaded fiber method and hydroflouride (HF) chemical etching. These approaches are well established, but applicable only to glass. Optical assembly architecture for multichannel fibers and optical devices is critical to optical fiber interconnections. Multichannel fiber-pigtail laser diode (LD) modules have potential for supporting higher data throughput and longer transmission distances. However, to be of practical use, these modules must be more precise. This work proposes and manufactures lensed plastic optical fibers (LPOF) array. This novel manipulation can be utilized to fabricate an aspherical lens on a fiber array after the UV curing of the photo-sensitive polymer; the coupling efficiency (CE) is increased and exceeds 47% between the LD array and the fiber array.


Micromachines ◽  
2018 ◽  
Vol 9 (10) ◽  
pp. 521 ◽  
Author(s):  
Georgia Konstantinou ◽  
Karolina Milenko ◽  
Kyriaki Kosma ◽  
Stavros Pissadakis

We demonstrate a three-port, light guiding and routing T-shaped configuration based on the combination of whispering gallery modes (WGMs) and micro-structured optical fibers (MOFs). This system includes a single mode optical fiber taper (SOFT), a slightly tapered MOF and a BaTiO3 microsphere for efficient light coupling and routing between these two optical fibers. The BaTiO3 glass microsphere is semi-immersed into one of the hollow capillaries of the MOF taper, while the single mode optical fiber taper is placed perpendicularly to the latter and in contact with the equatorial region of the microsphere. Experimental results are presented for different excitation and reading conditions through the WGM microspherical resonator, namely, through single mode optical fiber taper or the MOF. The experimental results indicate that light coupling between the MOF and the single mode optical fiber taper is facilitated at specific wavelengths, supported by the light localization characteristics of the BaTiO3 glass microsphere, with spectral Q-factors varying between 4.5 × 103 and 6.1 × 103, depending on the port and parity excitation.


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