We report the fabrication of extremely low NA preforms (<0.03), highly doped with Yb using a conventional Modified Chemical Vapor Deposition (MCVD) system. Our lowest NA preform (0.025 NA) was drawn to a 52um core step-index double-clad fiber operating in a single mode regime (M2=1.04). The fiber had a mode field diameter (MFD) and an effective area (Aeff) greater than 35um and 1000um2 respectively. In a fiber laser configuration, the efficiency was greater than 85% without any sign of photodarkening. To the best of our knowledge, by using our extremely low NA preforms we have demonstrated the largest MFD and Aeff to date for a single-mode step index double–clad Yb doped fiber without involving any micro-structuration.
We present a 3kW single-mode fiber laser based on an Yb-doped LMA fiber operating at 1080nm. The laser which is pumped by 9xxnm diode bars stacks. It is believed to be the highest power direct diode pumped single-mode fiber laser oscillator to date.
Fiber lasers have made significant progress in terms of power output, beam quality and operational robustness over the
past few years. Key to this progress has been advances in two technologies - fiber technology and 9xx nm diode laser
pump technology based on single emitters. We present the operational characteristics of our new high brightness 9xx nm
fiber laser pump sources based on diode laser bars and diode laser bar arrays and discuss the design trade offs involved
for realization of devices focused on this application. These trade offs include achieving the lowest slow axis divergence
while maintaining high wall plug efficiency and minimizing facet power density to maximize reliability.
In recent years fiber pulsed fiber lasers have began to challenge diode pumped solid state lasers in
performance. In particular double-clad fiber lasers and amplifiers with mJ energies and near diffraction
limited beam quality are gaining respect for applications such as materials processing, laser radar and
remote sensing. Frequency conversion of single-polarization fiber lasers further increases the application
space to such as underwater communications, underwater imaging, semiconductor processing and gas
Yb fiber lasers have to date produced several mJ pulse energy and several MW peak power but, largely
due to materials issues Er based fiber laser systems underperforms in comparison. Relevant technologies
In this paper we describe a multiwatt Nd3+ fiber laser pumped via a second cladding by the DIOMED 25 laser diode unit. This multiple diode array source is designed for coupling up to 25 Watts of diode power into a plastic-clad silica fiber of 400 micrometers diameter. The double-clad laser fiber is interchangeable with the normal PCS delivery fiber. The device operates at 1.058 micrometers with a slope efficiency > 50% and a 150 times brightness enhancement. This laser though useful in itself is also a key intermediate laser for generation of high powers at other wavelengths. Tandem pumping of Tm3+ and Er3+/Yb3+ fiber lasers at 1.058 micrometers enables efficient generation of 2.0 micrometers and 1.55 micrometers radiation respectively. In addition the Nd3+ laser can be operated close to 1.3 micrometers and there are prospects for in-fiber frequency doubling of the 1.06 micrometers line to generate a high power source in the green.
Conference Committee Involvement (5)
Fiber Lasers XIII: Technology, Systems, and Applications
15 February 2016 | San Francisco, California, United States
Fiber Lasers XII: Technology, Systems, and Applications
9 February 2015 | San Francisco, California, United States
Fiber Lasers XI: Technology, Systems, and Applications
3 February 2014 | San Francisco, California, United States
Fiber Lasers X: Technology, Systems, and Applications
4 February 2013 | San Francisco, California, United States
Fiber Lasers IX: Technology, Systems, and Applications
23 January 2012 | San Francisco, California, United States