All fibre laser system with 0.1 W output power in blue spectralrange

A ytterbium sensitised thulium-doped blue upconversion ZBLAN fibre laser pumped at 1065 nm by a high power, diode pumped, double clad fibre laser is demonstrated. With a pump power of 2.8 W at 1065 nm, a blue output power of 106 mW at 482 nm is achieved     

800/1060 nm dual-wavelength pumped TDFA using single active pump source

Novel 800/1060 nm dual-wavelength pumping sources for Tm/sup 3+/-doped fibre amplifiers (TDFAs) are reported: a Nd/sup 3+/-doped silica fibre laser or a Nd/sup 3+/-doped microstructured silica fibre laser, both pumped near 800 nm and emitting near 1060 nm, providing the two required TDFA pump wavelengths. A new regime of pump power ratios is explored, in which the 800 nm power is comparable to the 1060 nm power. Gain and noise figure are comparable with those obtained using individual pump modules at the two wavelengths.     

935nm Nd/sup 3+/ fibre laser incorporating tapered photonic bandgap fibre filter

An 8 cm length of photonic bandgap fibre was tapered in the middle to narrow the transmission windows. The tapered fibre was incorporated into a neodymium fibre laser system, in which it suppressed the strong gain peaks at 907 and 1080 nm and ensured lasing at 935 nm     

Cascaded Raman fibre laser for stable dual-wavelength operation

The authors have demonstrated a stable and tunable dual-wavelength Raman fibre laser, which can be used as a pump source for a hybrid type and gain controlled C- and L-band distributed Raman and lumped erbium-doped fibre amplifiers. Intensity and wavelength tuning of the two lasing modes at 1480 nm and 1500 nm are achieved by tuning one and both of the fibre gratings used in the laser cavity, respectively     

Narrow-linewidth, yb31-doped, hybrid microstructured fibre laser operating at 1178 nm

A narrow-linewidth fibre laser operating at 1178 nm that employs a double-clad Yb^{3+doped hybrid microstructured fibre, is demonstrated. The fibre suppresses amplified spontaneous emission by the photonic bandgap effect, and parasitic lasing at shorter wavelength range (1030? 1100 nm) was prevented. A narrow-linewidth (≪0.05 nm), CW output of 0.5 W at 1178 nm with a slope efficiency of 14%, was measured.}     

Brillouin fibre laser with 20 m-long photonic crystal fibre

Brillouin fibre laser is demonstrated using a very short length of photonic crystal fibre (PCF). A simple ring resonator is used in the experiment which consists of a 20 m long highly nonlinear PCF and 49 cm long Bismuth-based erbium-doped fibre (Bi-EDF). The proposed Brillouin laser is able to generate up to 3 Stokes and 3 anti- Stokes lines in the 1560 nm region at a channel spacing of 0.09 nm.     

Broadband tunable single frequency diode-pumped erbium doped fibre laser

A single frequency erbium fibre laser with continuous wavelength tuning over the range 1525-68 nm has been demonstrated using a unidirectional loop mirror (ULM) configuration. The fibre laser is diode pumped at 1480 nm with a threshold of 9 mW, slope efficiency of 12% and has a linewidth of less than 295 kHz.<>     

Multi-wavelength, continuous wave fibre Raman ring laser operatingat 1.55 μm

A four wavelength continuous wave, fibre Raman ring laser has been demonstrated at room temperature using fibre Bragg gratings as the wavelength-selective elements with applications as a multi-wavelength source for optical fibre telecommunications. Channel spacings were ~5 nm between 1551.6 and 1565.1 nm with 14.9 dBm total output power     

Efficient up-conversion pumping at 800 nm of an erbium-doped fluoride fibre laser operating at 850 nm

An erbium-doped fluorozirconate fibre laser has been constructed which uses up-conversion pumping at 801 nm to excite a higher-level laser transition at 850 nm. A slope efficiency of 38% was measured.<>     

High repetition rate passively Q-switched Nd/sup 3+/:Cr/sup 4+/ all-fibre laser

A passively Q-switched fibre laser comprising an Nd/sup 3+/-doped gain fibre spliced to a new Cr/sup 4+/-doped saturable absorber fibre delivers 0.3 nm-bandwidth continuous pulsed laser beam at 1084 nm, with 38 to 84 kHz repetition rate, and 3.0 to 6.4 /spl mu/s pulse duration.     

Multiwavelength-switchable SOA-fibre ring laser using sampled Hi-Bi fibre grating

A novel multiwavelength-switchable laser based on a semiconductor optical amplifier (SOA) within a fibre ring cavity with a sampled high-birefringence fibre grating is proposed. Four channels with 0.8 nm spacing have been generated at room temperature and switched to other channels with 0.4 nm wavelength-shift by adjusting an inserted polariser. The laser can be used in hierarchical cross-connect WDM networks employing an interleaved waveband concept.     

Compact fully fibre integrated source of 100 fs pulses at 1.1 /spl mu/m based on compression in holey fibre

A simple, compact, fully fibre integrated source of /spl sim/100 fs pulses at a wavelength of 1.1 /spl mu/m is reported. 4 ps pulses at 1063 nm from a modelocked fibre laser were amplified to 23 mW in a ytterbium-doped fibre amplifier and subsequently propagated through 62 m of holey fibre with a zero dispersion wavelength at 1040 nm. Soliton formation, breakup and self frequency shift resulted in the formation of /spl sim/100 fs pulses at 1.1 /spl mu/m. Wavelength tunability from 1113 to 1220 nm is demonstrated.     

Broadband diode-pumped fibre laser

Reports the observation of a strong dependence of the emission spectrum (centre wavelength and linewidth) of Nd:silica fibre lasers on pump wavelength. In a particular fibre, careful selection of the pump wavelength has led to the operation of a broadband fibre laser at 1060 nm with 19 nm FWHM bandwidth. When pumped with a 30 mW diode laser, it exhibits a 1 mW threshold, a 2.5 mW output, and an intrinsic average wavelength temperature stability of about 10 p.p.m./°C     

1 W single-transverse-mode Yb-doped double-clad fibre laser at 978nm

A novel all-glass Yb-doped double-clad fibre laser that emits over 1 W of single-transverse-mode output at 978 nm is described. This device is efficiently pumped with 2.5 W of launched power from a single 200 μm broad-area laser diode at 915 nm     

Tuneable multiwavelength semiconductor laser with single fibre output

A new multiwavelength semiconductor laser with singlemode fibre output is reported. The laser consists of a semiconductor laser array which is incorporated into an external cavity comprising a diffraction grating and a fibre loop mirror. This laser has five wavelength-locked output channels with a fixed separation of 2.5 nm. The centre wavelength may be tuned over 80 nm.<>     

Helical-core ytterbium-doped fibre laser

An Yb-doped fibre laser with a helical core trajectory in the cladding material has been demonstrated for the first time. The laser yields 350 mW of linearly-polarised, single-spatial-mode output at 1047 nm from a multimode core of diameter, 26 /spl mu/m, and numerical aperture, 0.14, when core-pumped by an Yb:YAG laser at 1030 nm.     

Optical amplification at 0.54 /spl mu/m by Er/sup 3+/-doped fluoride fibre

Demonstrated is a 16.5 dB all-fibre optical amplifier at 546 nm using Er³⁺-doped fluoride fibre for a signal power of -30 dBm by forward upconversion pumping of a 974 nm laser diode. Results show Er ³⁺-doped fluoride fibre is a promising candidate for 0.54 mum optical amplifiers     

High-power diode pumped upconversion fibre laser in red and green spectral range

A praseodymium-ytterbium-doped multimode upconversion ZBLAN fibre laser pumped with high brightness multimode diodes at 850 nm is demonstrated. With a pump power of 6.5 W, an output power >2 W at 635 nm and 0.3 W at 520 nm has been achieved.     

Fibre-optic digital transmission experiment with heterodyne detection

A single-channel single-polarisation all-fibre-optic transmission system at 830 nm wavelength with transmitter laser and a heterodyne receiver with local laser, monomode fibre coupler and APD mixer has been set up. The intermediate frequency was 1.5 GHz. 8.4 Mbit/s digital signals were transmitted over 280 m of single-polarisation fibre by a subcarrier modulated baseband method.     

Multiwavelength erbium-doped fibre laser based on ahigh-birefringence fibre loop mirror

A novel multiwavelength fibre laser is proposed, which is based on a fibre loop mirror formed by a high-birefringence (HiBi) fibre, a polarisation controller, and a directional coupler. By setting the polarisation controller properly, the HiBi fibre loop mirror acts as a polarisation-independent wavelength filter. With this configuration, the wavelength spacing of the laser can be varied accurately by adjusting the length of the HiBi fibre. Experimentally, by cooling the erbium-doped fibre with liquid nitrogen to reduce its homogeneous linewidth, stable emission at 16 wavelengths with a spacing of 0.8 nm and an amplitude variation of <5 dB was achieved