Path to doubling the efficiency of mid-IR erbium lasers.

It has been experimentally shown that a Cr:ZnSe optical amplifier can be successfully used for self-amplification of the cascade Er:YO laser. This is to our best knowledge the first demonstration of an optical amplifier where both signal and pump are delivered from a single laser source. Absorption and emission spectra of the Cr:ZnSe are perfectly positioned to amplify the output of the cascade Er:YO laser, when the 1.6 μm emission of the cascade laser serves as a pump, while 2.7 μm as a signal. We have also shown that this concept is valid for any bulk or fiber cascade erbium laser.