Yellow Silica Fiber Laser Delivering an Output Power of ~ 150 mW

Lanthanide-doped fiber lasers are sought after for many applications, as they can generate high-brightness signals through some of the most compact, rugged, and reliable laser systems available. Although high power fiber lasers have been mostly reported between 1 and
$3\ \mu\mathrm{m}$
, the recent advent of GaN laser diodes has provided a low-cost solution to efficiently pump lanthanide-doped fibers for visible laser emission. To date, watt-level operation of these lasers has been reported [1], [2], but only for active fibers based on fluoride glass, which is known for its constraining thermal and mechanical properties. While the use of such a host is needed for mid-infrared lasers due to its low phonon energy, it is not necessarily the case for visible laser emission. Indeed, for some rare-earth ions like Sm
³
+ and Dy
³⁺
, the large energy gap between the upper energy level responsible for visible emission (in the case of Dy
³⁺
,
⁴
F
9/2
) and the energy level directly below (in the case of Dy
³⁺
,
⁶
F
5/2
) allows a high phonon energy medium such as silica to be a suitable host for laser emission [3]. While visible silica fiber lasers show a lot of promise due to their excellent thermal and mechanical properties, very few demonstrations of such lasers have been made. Thus far, the record output power is set to 18 mW [4]. In this work, we present a monolithic Dy
³⁺
- doped aluminosilicate fiber laser yielding a maximum output power of 147 mW, which is eight times more than the previous record.