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. https://www.sahmbuffy.com/product-category/d-cell-ni-cd-and-ni-mh-batteries-and-battery-packs/