Amplification in a Fiber Laser

Fiber lasers of neodymium-doped glass have been used on a pulsed basis to amplify 1.06-μ radiation. To prevent oscillation, the ends are polished at an angle such that reflected light is lost from the cavity. With the high inversion which can then be obtained, gains as large as 5 × 104 have been observed in a 1-m long fiber. The gain was measured as a function of pumping energy and as a function of time during the pumping pulse at which the amplification was determined.