Specialty Optical Fibers Handbook

22.2 CLADDING PUMPED FIBERS

Early fiber lasers were side-pumped with a flashlamp, but in 1974, Julian

Stone and Charles Burrus [4] took the technology a significant step forward

when they demonstrated a neodymium-doped multimode fiber laser that was

end-pumped with a laser diode. However, at that time the only available tech-

nique for achieving an acceptable optical quality of the laser output was to

employ a fiber with a geometrically small core (on the order of a few microns).

The need to couple excitation energy directly into this small core meant that the

total achievable output power of these devices was limited to the milliWatt

range. With the advent of cladding pump fiber designs in 1988 [5], the limitation

to power scaling fiber devices became ...