All solid-state blue room-temperature thulium-doped upconversion fibre laser

Following the report by Grubb we describe an all solid state, single wavelength pumped, cw, room temperature, upconversion laser which has operated in the blue between 475nm and 483nm or in the near infrared at 778nm. We have pumped this device at both longer and shorter wavelengths than those reported by Grubb. The system uses Yb-doped silica fibre to convert the output from a diode pumped Nd:YLF laser to a wavelength in the range 1.05µm to 1.18µm. This is used to pump a Tm-doped ZBLAN fibre giving rise to an upconversion process which involves the sequential absorption of three pump photons to populate the 1G4 upper laser level as shown in Fig 1

An investigation into optical amplifiers and upconversion lasers using rare-earth doped fluorozirconate glass fibre

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WDM ring network employing a shared multiwavelength incoherent source

We propose and demonstrate a novel wavelength-division multiplexed (WDM) ring-network for wide-area, local-area, and access networks. The network employs a single, shared, multiwavelength incoherent source that is remotely located from network nodes. The use of a single incoherent source provides a straight-forward means of wavelength stabilization and potential for a cost-effective network. We demonstrate less than 10 -9 biterror-rate (BER) operation of a four-node network at per-node data rates of 622 Mb/s

A diode-pumped, first-window optical fibre amplifier providing up to +12dBm of output

The thulium ion is one of great interest when it is doped within fluorozirconate glass due to the number of transitions available for stimulated emission. One such transition is the 3F4 to 3H6 transition at 0.8 µm. This is of interest as it lies within the first window for optical communication. There is growing interest in the use of this window for local area networks, passive optical networks, or supervisory systems. Small signal amplification of up to 23 dB has been reported for this transition in a thulium-doped fluoride fibre using a Ti:sapphire laser as the pump source. We report here the first diode pumped operation of this optical amplifier. An intrinsic small signal gain in excess of 30 dB was achieved. With a launched 807-nm signal power of -10 dBm, intrinsic gain of 21 dB was observed, producing amplified output powers of +11 dBm. An intrinsic gain of greater than 20 dB was observed for signals over the spectral range of 802 nm to 810 nm. The greatest amplified output power obtained for this system was 12.8 dBm for 30 mW of launched diode pump power

Diode-pumped operation of a thulium doped fluoride fibre amplifier suitable for 1st- window systems

A fully connectorised diode laser pumped first window amplifier has been constructed, for the first time, around a thulium doped fluoride fibre. For a 780/806nm combination of pump and signal wavelengths, small signal gains of 25-26dB and gain efficiencies of 2.4dB/mW have been achieved. In addition, output powers approaching +13dBm are possible for a launched pump power of 31mW, which corresponds to a conversion efficiency of around 65%

Characterisation of a first window amplifier using a thulium doped fluoride fibre

A fully connectorized diode laser pumped first window amplifier has been constructed, for the first time, around a thulium doped fluoride fiber. For a 780/806 nm combination of pump and signal wavelengths intrinsic small signal gains of 25 - 26 dB and gain efficiencies of 2.4 dB/mW have been achieved. In addition output powers approaching +13 dBm from the doped fiber were possible for launched pump powers of 31 mW, which corresponds to a pump to signal conversion efficiency of around 64%. Minimum noise figures of 4 - 5 dB have been achieved with characteristics which mirror the output power performance. The 3 dB gain bandwidth for this transition has been measured at 9 - 10 nm for small signals, increasing to better than 15 nm under signal saturation condition

Efficient upconversion laser action in Tm³⁺ and Pr³⁺-doped ZBLAN fibres

Visible wavelength lasers are much sought after for many applications. In this paper we report that significant powers at blue (46 mw), green (5 mw) and red (30 mw) are now available from Tm3+ and Pr3+-doped ZBLAN fiber lasers using very convenient pumping schemes based on the Yb3+-doped silica fiber laser

Analysis of blue and red laser performance of the infrared-pumped praseodymium-doped fluoride fiber laser

The laser performance at 491 and 635nm of praseodymium-doped fluorozirconate fiber pumped at 1.01µm and 835nm is described and is interpreted with analytical solutions to the rate equations. Spectroscopic measurements of the absorption and the emission cross sections are presented, and the values are shown to be consistent with the observed lasing performance. The analytical model is shown to be a reliable indication of the optimum length of fiber for operation on the three-level 491nm transition

Efficient amplification in the first telecommunications window

Thulium-doped fluorozirconate fibre can be used as an efficient amplifier over the wavelength range 800 - 815nm in the first telecommunications window. A small-signal gain of 23dB has been achieved at 805nm with 50mW of launched pump power at 780nm. The fibre used for this demonstration had a core diameter of 3.5µm, numerical aperture 0.16 and thulium ion concentration 800ppm by weight. The background loss of the fibre was measured to be less than 0.1dB/m. These results suggest that a high gain 800nm amplifier employing an AlGaAs diode-pumped thulium-doped fluorozirconate fibre can now be made

A laser diode pumped optical amplifier in the first telecommunications window

Thulium doped fluorozirconate fibre has been shown to operate as an efficient amplifier over the wavelength range 800nm to 815nm in the first telecommunications window. Using a Ti:Sapphire laser at 780nm as pump source we have shown 23dB of gain at 805nm with 60mW of launched pump power