I.R. Perry

Frequency upconversion in Tm- and Yb:Tm-doped silica fibers

Frequency upconversion has been observed and studied in Tm3+-doped and Yb3+-sensitized Tm3+-doped silica fibers. In the singly singly doped fiber upconversion to the blue and UV has been observed under excitation in the red (660 nm) and infra-red (1.064µm). In the co-doped fiber upconversion has also been observed under excitation at around 800-900 nm.

An Ytterbium-doped Monomode Fibre Laser: Broadly Tunable Operation from 1·010 μm to 1·162 μm and Three-level Operation at 974 Nm

Abstract Continuous-wave laser action has been observed from an ytterbium-doped monomode fibre laser on the three-level transition at 974 nm and on the four-level transition at 1036 nm with slope efficiencies of 67% and 77% respectively, with respect to absorbed power. Tuning behaviour is described, in which polarisation control by means of fibre loops has allowed smooth continuous tuning from 1·010 μm to 1·162 μm.

A 1-Watt thulium-doped cw fibre laser operating at 2 μm

Abstract We report efficient high power (>62; 1 W) single transverse mode continuous-wave laser action at 2 μm in a thulium-doped silica-based fibre laser pumped by a Nd : YAG laser at 1.064 μm. The highest measured output power was 1.35 W. A threshold of 600 mW absorbed and slope efficiency of 37% with respect to absorbed power were observed.

Efficient superfluorescent emission at 974 nm and 1040 nm from an Yb-doped fiber

Abstract End-pumping of an Yb-doped single-mode fiber has yielded > 10mW and 30 mW of broadband superflourescence at 974 nm and 1040 nm, respectively. Slope efficiencies > 40% have been obtained. Pump wavelength dependent linewidths between 2 nm and 19 nm have been observed.

Frequency shifted feedback and frequency comb generation in an Er3+ -doped fibre laser

The temporal and spectral characteristics are reported of an Er3+ -doped fibre laser incorporating frequency shifted feedback. The output of the free running laser was found to be either continuous-wave or train of driven relaxation oscillations depending on cavity loss. The performance is described and a simple theoretical model is used to predict the main features. Under cavity matching conditions, a train of pulses was generated with a repetition rate equal to the roundtrip time. Injection seeding of the laser generated a discrete comb of optical frequencies for applications in optical metrology.

Lasing Characteristics Of Ytterbium, Thulium And Other Rare-Earth Doped Silica Based Fibers

We have experimentally studied the lasing characteristics of silica fibers doped with Yb, Tm, Pr and Ho and present a summary of these results.

Thulium-doped silica fiber lasers

The trivalent thulium ion is an interesting activator for silica fiber lasers because of the near infrared transition which is broadband tunable ( diode pumpable can be operated with photon conversion efficiencies greater than 100 and has yielded in excess of 1W output power when pumped by a cw Nd:YAG laser. The paper will review progress on this system and indicate some potential future developments.

Micro-fluorescence profiling of erbium-doped fibre preforms

Abstract A micro-fluorescence technique for profiling the spatial distribution of erbium ions doped into optical fibre preforms is reported. Profiles have been compared using fluorescence at wavelengths of 0.553 and 1.5 μm to identify a critical erbium concentration of about 0.12 wt%Er 3+ , where the effects of clustering become apparent. The addition of core co-dopants has been studied and found to have no significant effect on the active ion distribution. The variation in 1.5 μm fluorescence lifetime with position across the core has been measured. A pronounced reduction (up to 66%) in this lifetime at the core extremities was observed and indicates the presence of local ion environment disordering.