Yb-doped large mode area tapered fiber with depressed cladding and dopant confinement

Functional Fibers and Functional Fiber-Based Components for High-Power Lasers

“…With the development of fiber preform preparation and mechanical polishing technology, the studies of tapered fibers has evolved to more degrees of freedom along the longitudinal dimension, which is driven by better pump absorption capacity and greater single-mode potential. A series of representative results at several-kilowatt-level have been reported with near single-mode outputs [76,[258][259][260][261][262][263][264][265][266][267][267][268][269][270][271][272][273][274][275][276][277][278][279][280]. Table 2 summarizes the recent progress of tapered fibers for HPFLs applications.…”

“…Since the first experimental observation based on a piece of 10.5-m long-tapered fiber in 2008, which generated a CW output of 80 W (M 2 ~ 1.07) by employing the Yb-doped fiber with two ends of 27/834 μm and 5.8/177 μm [261], many optimistic results have been obtained. For example, the 600 W and 750 W single-mode oscillators [254,255], the 100 W polarization maintaining amplifier [262] and the ultra-large core birefringent fiber for high-power amplifiers [263]. To construct an all-fiberized format, a long-tapered fiber amplifier with a maximum output power of 1.47 kW was realized and the M 2 factor was 1.8 [264].…”

Ultra-large core birefringent Yb-doped tapered double clad fiber for high power amplifiers

“…To date, many different fiber-optic lasers and amplifiers containing the T-DCF have been demonstrated: a 750W CW ytterbium fiber laser [9], high power narrowband CW amplifiers [10,11], random tapered fiber laser [12], a nanosecond actively-Q-switched laser [13], amplifiers of nanosecond pulses [14,15], and even a powerful pulsed supercontinuum optical source [16].…”

“…The amplification of a short pulse is one of the most promising fields for the T-DCF application. The T-DCF has already been successfully used for the amplification of nanosecond [14,15] and picosecond pulses [5,17]. Although the advantages of the T-DCF for amplifying the pulses was first demonstrated a decade ago [5], there is still room for further improvement of their performance.…”

“…To date, Yb-doped birefringent T-DCFs with a relatively modest core diameter of 45μm [18], 56 μm [15] and 60 μm [14] have been demonstrated. Isotropic active T-DCFs with a large core diameter of 100μm [17] and even 200μm [8] and an anisotropic passive tapered fiber with a core size of 70μm [19] have also been demonstrated.…”