ABSTRACT
For the purposes of this chapter we will split ber devices into two broad categories, CW and pulsed ber lasers. The attraction of ber laser devices is the monolithic nature of their architecture, using a series of spliced ber components from the diode pump source through to the output of the laser. The lack of any glass/air surfaces along the chain of components eliminates any misalignment and contamination problems during the lifetime of the laser and increases efciency due to the reduced losses at the interfaces. In the case of a CW ber laser, a typical monolithic architecture is shown in Figure 6.1 [1], showing the key elements of an Yb-doped ber laser operating around 1060 nm. These components include the ber Bragg gratings (FBGs) forming the laser cavity, the tapered fused bundles (TFBs) for multiplexing many pump diodes, the pump laser diodes themselves along with components such as cladding light stripper and tap coupler. This entire chain of components is optimized for low splice loss between bers, particularly at high powers where excess loss is not only costly but also leads to lower reliability. Currently, there are multiple commercial suppliers for all the key components for making these CW laser devices even at the kW power level, as we will discuss in later chapters.
