Rare-earth oxide doped tellurite glass near and mid-IR fibre lasers
Animesh Jha1(a.jha@leeds.ac.uk), Billy Richards1, Joris Lousteau1
1
Institute for Materials Research, School of Process, Environment and Materials
Engineering, The University of Leeds, Leeds, LS2 9JT, UK
Yuen Tsang2, David Binks2
2
Photon Physics Group, School of Physics and Astronomy, The University of
Manchester, Manchester, M13 9PL, UK
Abstract
The invited paper focuses on the advantages of tellurite glass as a medium for
engineering mid-IR fibre lasers and light sources. The lower phonon energy of the host
glass and its high-earth oxide solubility offers an excellent opportunity for engineering
near and mid-IR lasers and light sources for lidar, medicine and remote sensing
applications. In the invited talk, we will discuss both the single and multi-core fibre
geometries in engineering such devices. Specifically we will present a highly efficient
CW Tm3+-doped tellurite fibre laser operating at 1.88-1.97 μm in figure 1, and a
Tm3+/Ho3+-codoped tellurite fibre laser operating at 2.05-2.10 μm in figure 2, when
pumped using a ~1.6 μm Er3+/Yb3+-codoped silica fibre laser. The ~1.6 μm pump
excites the Tm3+: 3F4 which in the case of the Tm3+-doped fibre is the upper laser level,
and in the Tm3+/Ho3+-codoped fibre the energy is efficiently transferred to the Ho3+: 5I7
upper laser level. A maximum slope efficiency and output power of 76% and 283 mW,
respectively, was achieved in a 32 cm long Tm3+-doped fibre. By comparison in the
Tm3+/Ho3+-codoped fibre a maximum slope efficiency of 62% and an output power of
160 mW was achieved from a 76 cm long fibre (figure 1a). For both fibres, the optimum
arrangement was found to be with a highly reflective mirror at the pump end and 11%
Fresnel reflection at the output end. These results represent the highest power and
longest wavelength ever achieved from a tellurite fibre laser.
3+
Tm -doped tellurite fibre
3+
3+
Tm /Ho -codoped tellurite fibre
0.30
Laser output power (W)
0.25
0.20
Slope = 76%
0.15
Slope = 62%
0.10
0.05
 
0.00
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
Launched pump power (W)
0.45
0.50
 
0.55
1 ) Ch 1 :
50 0 m Vo lt 2 .5 u s
Figure 1. (a): Maximum slope efficiencies and output powers of the Tm3+ and Tm3+/Ho3+-doped tellurite
fibre lasers when pumped at ~1.6 μm. (b): Output laser pulses from the Q-switched Tm3+/Ho3+-codoped
tellurite fibre laser.
The ~2.1 μm Tm3+/Ho3+-codoped fibre laser was also actively Q-switched using a
mechanical chopper operating at a frequency of 19.2 kHz. A maximum average power
of 55 mW and pulse energies of >0.65 μJ were achieved with pulse widths in the 100160 ns range. The characteristic output of the Q-switched fibre laser showed between
three and five pulses per switch opening (figure 1b) which reduced the maximum pulse
energy by distributing the energy amongst several pulses. This result represents the first
ever pulsed tellurite fibre laser.
PRIMARY TOPIC: M
SECONDARY TOPIC: I
THIRD TOPIC: R
PREFERRED FORMAT OF PRESENTATION (ORAL/POSTER): O