A Novel Regeneration Technique for Free Space Optical Communication Systems

Abstract

We propose a novel technique to regenerate the optical signal in a relay-based free space optical link. Our proposed regenerator is based on an Electro-absorption modulator whose optical input is the signal to be regenerated, while the electrical input is extracted by processing a part of the optical input signal. The signal at the output of the proposed regenerator based relay has lower intensity fluctuations compared to a conventional optical amplifier based relay. We have tested our proposed regenerator-based relay under medium and strong turbulence conditions by choosing the refractive index structure parameters as 5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-15</sup> m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2/3</sup> and 5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-10</sup> m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2/3</sup> , respectively. Our simulation results show that the proposed regenerator-based relay reduces the received power penalty by 3.5 dB compared to the conventional amplifier-based relay, under strong turbulence conditions.