There are 4 types of multimode fiber-coupled laser diodes:

Single Emitter: When the laser diode chips are individually assembled on the submount and individually packaged in the laser diode module. What we’re talking about here is typically a 15W power coupled to a 105 (core)/125µm (cladding) laser diode

Multiple Emitters: When multiple emitters are separated and optically coupled together with other isolated emitters in multimode fiber (Figure 19-right). As a result, output power levels can be scaled to hundreds of watts, and the size of the fibers can be kept small, such as 100 or 200 µm cores.

Single bar: When multiple emitters are held together as a single bar (Figure 17) and assembled in a single laser diode module. What we’re talking about here is typically around 50 W of power, typically coupled to a 200 µm (core)/240 µm (cladding) laser diode.

Doba Bars: When multiple bars are assembled in a large water-cooled package and coupled in a large diameter multimode fiber. What we are talking about here is 100 watts or even KW coupled into, for example, 600 or 800 µm core multimode fiber.