scholarly journals The Illumination of Thunderclouds by Lightning: Part 3: Retrieving Optical Source Altitude

2021 ◽  
Author(s):  
Michael Peterson ◽  
Tracy E. L. Light ◽  
Douglas Mach
Keyword(s):  
Optical Source

A comparative study on the cold type and thermal type field emission guns used in the same electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 58-59
Author(s):  
M. Iwatsuki ◽  
Y. Kokubo ◽  
Y. Harada
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Signal To Noise Ratio ◽  
Electron Source ◽  
Resolving Power ◽  
Optical Source ◽  
Experimental Conditions ◽  
High Brightness ◽  
Illumination System ◽  
Transmission Electron

On accout of its high brightness, small optical source size, and minimal energy spread, the field emission gun (FEG) has the advantage that it provides the conventional transmission electron microscope (TEM) with a highly coherent illumination system and directly improves the resolving power and signal-to-noise ratio of the scanning electron microscope (SEM). The FEG is generally classified into two types; the cold field emission (C-FEG) and thermal field emission gun (T-FEG). The former, in which a field emitter is used at the room temperature, was successfully developed as an electron source for the SEM. The latter, in which the emitter is heated to the temperature range of 1000-1800°K, was also proved to be very suited as an electron source for the TEM, as well as for the SEM. Some characteristics of the two types of the FEG have been studied and reported by many authors. However, the results of the respective types have been obtained separately under different experimental conditions.

scholarly journals Stable Radio Frequency Transmission of Single Optical Source Over Fiber Based on Passive Phase Compensation

2021 ◽  
Vol 13 (1) ◽  
pp. 1-7
Author(s):  
Chen Hu ◽  
Bin Luo ◽  
Wenlin Bai ◽  
Wei Pan ◽  
Lianshan Yan ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Phase Compensation ◽  
Optical Source ◽  
Passive Phase

Comparative analysis of SISO and wavelength diversity-based FSO systems at different transmitter power levels

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Varun Srivastava ◽  
Abhilash Mandloi ◽  
Dhiraj Kumar Patel
Keyword(s):  
Optical Signal ◽  
Free Space Optical ◽  
Optical Source ◽  
Transmit Power ◽  
Single Input Single Output ◽  
Transmitter Power ◽  
Single Output ◽  
Communication Links ◽  
Single Input ◽  
Matching Performance

AbstractFree space optical (FSO) communication refers to a line of sight technology, which comprises optical source and detector to create a link without the use of physical connections. Similar to other wireless communication links, these are severely affected by losses that emerged due to atmospheric turbulence and lead to deteriorated intensity of the optical signal at the receiver. This impairment can be compensated easily by enhancing the transmitter power. However, increasing the transmitter power has some limitations as per radiation regulations. The requirement of high transmit power can be reduced by employing diversity methods. This paper presents, a wavelength-based diversity method with equal gain combining receiver, an effective technique to provide matching performance to single input single output at a comparatively low transmit power.

Multi-Site Cr3+ Occupation Related Broadband NIR Luminescence in Cr3+-doped Li3Mg2NbO6

CrystEngComm ◽  
2021 ◽  
Author(s):  
Fen Xiao ◽  
Chengning Xie ◽  
Shikun Xie ◽  
Rongxi Yi ◽  
Huiling Yuan ◽  
...  
Keyword(s):  
Near Infrared ◽  
Nir Spectroscopy ◽  
Luminescent Materials ◽  
Optical Source ◽  
Nir Emission ◽  
Nir Luminescence

Broadband near infrared (NIR) luminescent materials have attracted great attention recently for the advance smart optical source of NIR spectroscopy. In this work, a broadband NIR emission from 650 nm...

scholarly journals Photonic image rejection mixer based on polarization manipulation of a broadband optical source

2021 ◽  
pp. 1-1
Author(s):  
Zhiyao Jia ◽  
Guangyi Li ◽  
Difei Shi ◽  
Ming Li ◽  
Ning Hua Zhu ◽  
...  
Keyword(s):  
Image Rejection ◽  
Optical Source ◽  
Image Rejection Mixer

WDM optical-source generation using wavelength-locked FP-LDs with a spectrally sliced FP-LD

2004 ◽  
Vol 43 (1) ◽  
pp. 84-87
Author(s):  
Woo-Jun Choi ◽  
Sang-Jin Han ◽  
Hyuk-Choon Kwon ◽  
Sang-Kook Han
Keyword(s):  
Optical Source

Dual Fluorescence Emission by Irradiation of Single Optical Source for Fluorescein Sodium and 5-ALA Applications

2021 ◽  
Author(s):  
So Yoon Kwon ◽  
Ki-Cheol Yoon ◽  
Kwang Gi Kim
Keyword(s):  
Brain Tumors ◽  
Blood Vessels ◽  
Aminolevulinic Acid ◽  
Fluorescence Emission ◽  
Dual Band ◽  
Band Pass Filter ◽  
Fluorescein Sodium ◽  
Dual Fluorescence ◽  
Optical Source ◽  
Pass Filter

Abstract Most brain surgeries aim to completely resection a tumor. However, the arrangement of blood vessels around brain tumors is often complex. Moreover, the tumors and blood vessels have similar colors, making it difficult to identify the boundaries between them with the naked eye. Fluorescent staining is a method used to distinguish the borders between brain tumors and blood vessels. The fluorescent contrast agents commonly used to observe tumors are 5-aminolevulinic acid (5-ALA) and fluorescein sodium (FS), which have different surgical sensitivities, depending on the type of tumor. In this article, a dual band band-pass filter (BPF) with dual-wavelength emission for 5-ALA and FS is designed, and the dual-band BPF capable of inducing simultaneous fluorescence emission of FS and 5-ALA was investigated experimentally to improve accuracy, speed, and energy efficiency in clinical settings. The possibility of dual fluorescence emission with a single irradiation is proposed. The proposed fluorescent dual-band filter has the advantage of saving energy, reducing auxiliary manpower and unit costs, and reducing operating room space requirements by producing two fluorescence diagnostic effects using a single equipment.

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