Investigation of Free Space Optical Detection Module Operating at the Wavelength Range of 8-12 μm
The paper presents the construction and test results of a long-term radiation detector module for free space optical communication operated at the wavelength range of 8–12 μm. In the module a Polish detector manufactured in the company Vigo System S.A. was applied. High sensitivity of the detection module was achieved through a multi-layered heterostructure HgCdTe with immersion lens, which is optimized for the radiation detection at the wavelength of 10 μm. Detector noises were reduced as a result of detector cooling by means of four-stage thermoelectric cooler. The developed detection module is dedicated to design a next-generation optical data link. The link will be characterized by a greater range in difficult weather conditions in relation to the currently offered links operating at the shorter wavelengths.
Experimental Study of the Free Space Optics Communication System Operating in the 8–12 µm Spectral Range
(1) Background: Free space optics communication (FSO) has improved wireless communication and data transfer thanks to high bandwidth, low power consumption, energy efficiency, a high transfer capacity, and a wide applicability field. The FSO systems also have their limitations, including weather conditions and obstacles in the way of transmission. (2) Methods: This research assesses the atmospheric conditions’ influence on the intensity of received radiation, both experimentally and theoretically. The construction of a laboratory test stand of the FSO system, which is operating in the third-atmosphere transmission window (8–12 µm), is proposed. Next, considering different atmospheric conditions, the experimental validation was conducted, both in a laboratory and real conditions. (3) Results: The measurements were carried out for two optical links working with wavelengths of 1.5 µm and 10 µm. It was found that optical radiation with a wavelength of about 10 µm is characterized by better transmission properties in the case of limited visibility (e.g., light rain and fogs) than in the case of near-infrared waves. The same conclusion was found in analytical investigations. (4) Conclusions: The results obtained show that optical radiation with a wavelength of about 10 µm in limited visibility is characterized by better transmission properties than near-infrared waves. This demonstrates the validity of designing FSO links operating in the range 8–12 µm band, e.g., based on quantum cascade lasers and HgCdTe photodiodes.
Climate change, disasters and electricity generation
Abbrevia ons Foreword 1. Introduc on 8 2. The impacts of changing climate pa erns and changing disaster risks on energy 9 op ons and electricity genera on infrastructure 2.1 The rela onship between climate change and disaster risks 10 2.2 The impact of changing climate pa erns and changing disaster risks on electricity 11 genera on from fossil fuels 2.3 The impact of changing climate pa erns and changing disaster risks on electricity 14 from nuclear power 2.4 The impact of changing climate pa erns and changing disaster risks on electricity 17 genera on from renewable energy 2.4.1 Hydropower 17 2.4.2 Wind Energy 19 2.4.3 Bioenergy 22 2.4.4 Solar Energy 24 3. Climate change and changing disaster risks: implica ons for energy policy and 26 planning