A noiseless linear amplifier (NLA) performs the highest-quality amplification allowable under the rules of quantum physics. Unfortunately, these same rules conspire against us via the no-cloning theorem, which constrains NLA operations to the domain of probabilistic processes. Nevertheless, they are useful for a wide variety of quantum protocols, with numerous proposals assuming access to an optimal NLA device that performs with the maximum possible success probability. Here we propose the first linear-optics NLA protocol that asymptotically achieves this success probability bound by modifying the Knill-Laflamme-Milburn near-deterministic teleporter into an amplifier.
