A multi-stage optical fiber amplifier, comprising: a preamplifying stage, comprising: a first optical fiber comprising a gain medium; and a first pump source arranged to optically pump the first optical fiber, wherein optically pumping the first optical fiber amplifies optical signals in a wavelength range transmitted through the gain medium of the first optical fiber; and a booster amplifying stage, comprising: a second optical fiber comprising a gain medium, wherein the second optical fiber is optically coupled to the first optical fiber and arranged to receive optical signals from the first optical fiber; a second pump source arranged to optically pump the second optical fiber, wherein optically pumping the second optical fiber amplifies optical signals in the wavelength range transmitted through the gain medium of the second optical fiber and generates excess heat and excess photons; a fiber encapsulation structure comprising: a first layer, comprising a polymer layer that at least partially surrounds the second optical fiber, wherein the polymer layer is optically transparent; a heatsink layer disposed adjacent to and in direct contact with the polymer layer, wherein the heatsink layer conducts the excess heat away from the second optical fiber; and a second layer, separate from the first layer, comprising an optically transparent layer disposed adjacent to the polymer layer opposite the heatsink layer, wherein the optically transparent layer transmits the excess photons away from the second optical fiber and out of the fiber encapsulation structure. a preamplifying stage, comprising: a first optical fiber comprising a gain medium; and a first pump source arranged to optically pump the first optical fiber, wherein a first optical fiber comprising a gain medium; and a first pump source arranged to optically pump the first optical fiber, wherein optically pumping the first optical fiber amplifies optical signals in a wavelength range transmitted through the gain medium of the first optical fiber; and a booster amplifying stage, comprising: a second optical fiber comprising a gain medium, wherein the second optical fiber is optically coupled to the first optical fiber and arranged to receive optical signals from the first optical fiber; a second pump source arranged to optically pump the second optical fiber, a second optical fiber comprising a gain medium, wherein the second optical fiber is optically coupled to the first optical fiber and arranged to receive optical signals from the first optical fiber; a second pump source arranged to optically pump the second optical fiber, wherein optically pumping the second optical fiber amplifies optical signals in the wavelength range transmitted through the gain medium of the second optical fiber and generates excess heat and excess photons; a fiber encapsulation structure comprising: a first layer, comprising a polymer layer that at least partially surrounds the second optical fiber, wherein the polymer layer is optically transparent; a heatsink layer disposed adjacent to and in direct contact with the polymer layer, wherein the heatsink layer conducts the excess heat away from the second optical fiber; and a second layer, separate from the first layer, comprising an optically transparent layer disposed adjacent to the polymer layer opposite the heatsink layer, wherein the optically transparent layer transmits the excess photons away from the second optical fiber and out of the fiber encapsulation structure. a first layer, comprising a polymer layer that at least partially surrounds the second optical fiber, wherein the polymer layer is optically transparent; a heatsink layer disposed adjacent to and in direct contact with the polymer layer, wherein the heatsink layer conducts the excess heat away from the second optical fiber; and a second layer, separate from the first layer, comprising an optically transparent layer disposed adjacent to the polymer layer opposite the heatsink layer, wherein the optically transparent layer transmits the excess photons away from the second optical fiber and out of the fiber encapsulation structure.