High-Peak-Power Femtosecond Pulse Generation by Nonlinear Compression in a Yb-Doped Hybrid Fiber

Abstract

We demonstrate a Yb-doped hybrid fiber with anomalous dispersion in the 1 μm spectral range, where asymptotically single-mode behavior is achieved with a differential mode amplification technique. The fiber has a dispersion of 70-100 ps/(nmkm) in the spectral range from 1.020 μm to 1.055 μm and a sharp dispersion peak (approximately 400 ps/(nm•km) near 1.064 μm) caused by the modes anti-crossing. The relatively large hybrid mode field diameter (8 μm) allows us to demonstrate high-peak-power femtosecond pulse generation via nonlinear chirped pulse compression in both dispersion regimes. Operation near 1.064 μm allows us to compress narrowband (3 dB spectral width of 2 nm) 6 ps pulses down to a duration of 250 fs with a peak power of 3.3 kW. Operation in the spectral region with a nearly constant anomalous dispersion is found to be optimal for the compression of wideband pulses. In particular, 1 ps pulses centered at 1.03 μm with a spectral width of approximately 11 nm are compressed down to 90 fs with a peak power of approximately 10 kW, which to the best of our knowledge is the best result for all-fiber (i.e., without external bulk compressors) systems operating near 1 μm.

Breaking the Stringent Trade-Off Between Mode Area and NA for Efficient High-Power Fiber Lasers Around 2 μm

“…LP02 curve crosses LP31 and LP41 curves), these are resonant couplings. This a common feature of M-type fibers and has been reported earlier [34][35].…”

“…It is also important to mention that, passive fibers similar but more complicated than the Mtype fibers have been successfully fabricated using MCVD process [31][32][33]. The active version of these fibers with confined doping of Yb 3+ and co-dopants ions in central core have been fabricated using rod-in-tube technique [34]. An Yb 3+ and co-doped preform was fabricated either using solution doping or vapour phase deposition and was further jacketed inside a silica tube having high-index layers deposited using chemical vapour deposition [34].…”

“…The active version of these fibers with confined doping of Yb 3+ and co-dopants ions in central core have been fabricated using rod-in-tube technique [34]. An Yb 3+ and co-doped preform was fabricated either using solution doping or vapour phase deposition and was further jacketed inside a silica tube having high-index layers deposited using chemical vapour deposition [34]. Aleshkina et al used the rodin-tube technique, possibly their design is much more complicated having two high-index layers and one absorbing layer [34].…”

“…to the ring. Recently Aleshkina et al, for the first time, demonstrated the exploitation of the anomalous dispersion profile of the LP02 and LP03 mode for non-linear applications using M-type fibers [31][32][33][34]. Thereafter, Jain et al also proposed the exploitation of the anomalous dispersion profile of the LP02 mode for mid infrared supercontinuum generation [35].…”

Segmented Cladding Fiber With a High-Index Ring in Core for Wideband Single-Mode Operation in Any Bending Orientation

“…Finally, the fiber can be prepared using the stack-and-draw technique from the stacked preform with the realized preform surrounded by alternatively arranged F-doped, and index-raising dopants doped silica rods. It's important to mention a similar structure with two layers of high-index rings has been fabricated using the MCVD process in conjunction with the rod-in-tube method [40]. The silica-glass-based segmented cladding fiber has also been fabricated [41].…”