A multi-hop free space optical link based on a regenerative relay

Abstract

A multi-hop free space optical link based on all-optical relays is presented. All-optical relays are either composed of simple optical amplifiers or optical regenerators. It has been shown that after a certain number of hops, the amplifier based relay cannot extend the range of the free space optical link. Therefore, we have investigated the use of a self phase modulation based regenerator as a substitute for simple amplifier based relay. By employing the regenerative relay, a 10 Gbps optical signal having pulse width of 7 ps is transmitted over a distance of 8 km of free space optical link. The free space optical link is modeled on the basis of Gamma-Gamma channel model in the strong turbulence regime. The performance of the link is observed on the basis of bit error rate analysis. It has been shown that under strong turbulence and accumulation of amplifier noise, the range of the link can only be extended by employing an optical regenerator.

Keywords

• Free space optics
• Gamma-Gamma channel model
• Optical regeneration