A Novel Regeneration Technique for Free Space Optical Communication Systems

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 <inline-formula> <tex-math notation="LaTeX">$5\times 10^{-15}\,\,m^{-2/3}$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$5\times 10^{-10}\,\,m^{-2/3}$ </tex-math></inline-formula>, respectively. Our simulation results show that the proposed regenerator-based relay reduces the received power penalty by <inline-formula> <tex-math notation="LaTeX">$3.5~dB$ </tex-math></inline-formula> compared to the conventional amplifier-based relay, under strong turbulence conditions.