Optical Wireless Link Operated at the Wavelength of 4.0 µm with Commercially Available Interband Cascade Laser.

Janusz Mikołajczyk,Robert Weih,Marcin Motyka

doi:10.3390/s21124102

Abstract

This paper evaluates the key factors influencing the design of optical wireless communication (OWC) systems operating in the mid-infrared range. The performed analysis has shown that working in this spectral “window”, compared to other wavelengths, is more effective in reducing the attenuation of radiation. The main goal was to verify the capabilities of the “on-shelf” interband cascade (IC) laser in the context of OWC system construction, considering its output power, modulation rate, room temperature operation, and integrated structure. For this purpose, a lab model of a data link with IC laser has been developed. Based on its main parameters, the estimation of signal-to-noise power ratio versus data link range was made. That range was about 2 km for a case of low scintillation and relatively low visibility. In the experimental part of the work, the obtained modulation rate was 70 MHz for NRZ (non-return-to-zero) format coding. It is an outstanding result taking into consideration IC laser operated at room temperature.

Highlights

Nowadays, microwave communication technologies have reached the upper limit of data throughput
These windows are located around 0.8 μm and 1.55 μm in near-infrared (NIR), from 3.0 to 5.2 μm in mid-infrared (MWIR), and from 8 to 12 μm in longwavelength infrared (LWIR) [1]
Some limitations have been defined by the light losses of the space propagation determined by air compounds, weather conditions or air turbulence

Summary

Introduction

Microwave communication technologies have reached the upper limit of data throughput. The interest in laser technology in optical wireless communication (OWC) has been renewed. From the practical point of view, this technology applies to devices operating in the range of several atmosphere transmission windows, which are characterized by lower propagation losses. These windows are located around 0.8 μm and 1.55 μm in near-infrared (NIR), from 3.0 to 5.2 μm in mid-infrared (MWIR), and from 8 to 12 μm in longwavelength infrared (LWIR) [1]. Available OWC systems most often operate in the NIR range in which well-developed optoelectronic technologies exist. MWIR is a highly transparent optical transmission window in the atmosphere, mainly characterized by a “lack” of water vapor absorption. There is a lower beam distortion due to beam scattering, beam wandering, loss of spatial coherence, or scintillation [2,3]

Methods

Results

Conclusion