Performance of optically preamplified direct detection receivers in presence of laser chirp. Part 2: Near travelling-wave and Fabry-Perot amplifier cases

1989 ◽  
Vol 136 (5) ◽  
pp. 256
Author(s):  
R.S. Fyath ◽  
J.J. O'Reilly
2018 ◽  
Vol 176 ◽  
pp. 02021 ◽  
Author(s):  
Alexander Geiss ◽  
Uwe Marksteiner ◽  
Oliver Lux ◽  
Christian Lemmerz ◽  
Oliver Reitebuch ◽  
...  

By the end of 2017, the European Space Agency (ESA) will launch the Atmospheric laser Doppler instrument (ALADIN), a direct detection Doppler wind lidar operating at 355 nm. An important tool for the validation and optimization of ALADIN’s hardware and data processors for wind retrievals with real atmospheric signals is the ALADIN airborne demonstrator A2D. In order to be able to validate and test aerosol retrieval algorithms from ALADIN, an algorithm for the retrieval of atmospheric backscatter and extinction profiles from A2D is necessary. The A2D is utilizing a direct detection scheme by using a dual Fabry-Pérot interferometer to measure molecular Rayleigh signals and a Fizeau interferometer to measure aerosol Mie returns. Signals are captured by accumulation charge coupled devices (ACCD). These specifications make different steps in the signal preprocessing necessary. In this paper, the required steps to retrieve aerosol optical products, i. e. particle backscatter coefficient βp, particle extinction coefficient αp and lidar ratio Sp from A2D raw signals are described.


Nanophotonics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 2251-2272 ◽  
Author(s):  
Zhengzheng Liu ◽  
Sihao Huang ◽  
Juan Du ◽  
Chunwei Wang ◽  
Yuxin Leng

AbstractThe rapid advancement of perovskite-based optoelectronics devices has caught the world’s attention due to their outstanding properties, such as long carrier lifetime, low defect trap density, large absorption coefficient, narrow linewidth and high optical gain. Herein, the photonic lasing properties of perovskites are reviewed since the first stimulated emission of perovskites observed in 2014. The review is mainly focused on 3D structures based on their inherently active microcavities and externally passive microcavities of the perovskites. First, the fundamental properties in terms of crystal structure and optical characteristics of perovskites are reviewed. Then the perovskite lasers are classified into two sections based on the morphology features: the ability/inability to support lasing behaviors by themselves. Every section is further divided into two kinds of cavities according to the light reflection paths (Standing wave for the Fabry–Pérot cavity and travelling wave for the Whispering-Gallery-Mode cavity). The lasing performance involves fabrication methods, cavity sizes, thresholds, quality factors, pumping sources, etc. Finally, some challenges and prospects for perovskite lasers are given.


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