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.}     

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     

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.     

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     

Extruded singlemode, high-nonlinearity, tellurite glass holey fibre

The fabrication of the first singlemode tellurite glass holey fibre produced from an extruded preform is reported. Robust singlemode guidance was observed at 1047 nm in the fabricated small core holey fibre. An effective mode area of 2.6 /spl mu/m/sup 2/ and high effective nonlinearity of 580 W/sup -1/ km/sup -1/ at 1047 nm were predicted. The fibre loss was measured to be 3.5 dB/m at 1050 nm, and 5.8 dB/m at 1550 nm.     

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.     

High-power cascaded Raman fibre laser using phosphosilicate fibre

A 13.2 W second cascade phosphosilicate cascaded Raman fibre using a 450 m phosphosilicate singlemode optical fibre is demonstrated. The lasing wavelength is 1539 nm and the conversion efficiency is 32.5%. This is the highest output power ever reported from a cascaded Raman fibre laser in the 1400-1600 nm range.     

Wideband gain flattened erbium fibre amplifier using a photosensitive fibre blazed grating

An erbium fibre amplifier with a highly flattened gain spectrum is demonstrated for the first time using an all fibre photosensitive Bragg grating. An ASE spectrum flattened to within +or-0.5 dB over a bandwidth of 35 nm in the 1550 nm window is achieved with a 3 mm long radiation coupling Bragg fibre grating.<>     

Flatly broadened supercontinuum generation at 10 Gbit/s using dispersionflattened photonic crystal fibre with small normal dispersion

Supercontinuum generation at 10 Gbit/s using a nonlinear dispersion-flattened photonic crystal fibre is experimentally demonstrated. The fibre has small normal dispersion with a variation smaller than 1.5 ps nm^-1 km^-1 between 1500 and 1650 nm. The supercontinuum with a flatly broadened spectrum of 92 nm (at 6 dB) in the 1.55 mum region is generated by injecting 1545 nm, 1.5 ps optical pulses into an 80 m-long fibre     

Low-cost continuous-wave supercontinuum generation using multimode 975 nm pump lasers

A low-cost continuous-wave supercontinuum source is demonstrated with optical spectral coverage from less than 1200 to more than 2000 nm, using low-cost multimode 975 nm pump lasers. The laser consists mainly of highly nonlinear fibre, Yb/Er doped fibre and 975 nm pump lasers.     

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     

Tunability of erbium-doped fibre ring laser based on bending loss of active fibre

A single frequency depressed-cladding erbium-doped fibre ring laser which can be tuned by exploiting the fibre bending losses has been proposed and experimentally demonstrated. A tunability range of about 44 nm, between 1491 and 1535 nm, has been measured. A saturable absorber formed by an unpumped erbium-doped fibre has been employed to guarantee single frequency operation     

Long periodic superstructure Bragg gratings in optical fibres

A 40 mm long optical fibre grating superstructure is written by translating an ultraviolet writing beam along a fibre and phase-mask assembly while its intensity is periodically varied. The grating reflects at multiple wavelengths, equally spaced by 0.13 nm, over a range of more than 1.0 nm. This grating structure has applications in signal processing and tunable fibre lasers     

Wavelength tunable CW Raman fibre ring laser operating at 1486-1551nm

A continuous-wave, wavelength tunable Raman fibre ring laser has been demonstrated operating at 1485-1551 nm with peak output power of over 400 mW, pumped at 1420 nm by a 1.58 W fibre laser     

Strong 157 nm F2-laser photosensitivity-locking ofhydrogen-loaded telecommunication fibre for 248 nm fabrication oflong-period gratings

Strong (>20 dB) long-period fibre gratings were fabricated by combining F₂-laser photosensitivity-locking of hydrogen-soaked telecommunication fibre and KrF-laser grating formation. The 157 nm pretreatment permanently enhances the fibre photosensitivity response to the low-energy 248 nm photons. Thermal annealing at 120°C for 24 h improves the grating stability without diminishing the enhancement     

Two-mode fibre spatial-mode converter using periodic coredeformation

Efficient conversion between the LP₀₁ and LP₁₁ modes in a two-mode fibre is achieved by periodically ablating the fibre surface with a CO₂ laser and then annealing the fibre with an electric arc. The resulting periodic core deformation produces 99% mode conversion over a 37 nm bandwidth around 1540 nm and 0.38 dB insertion loss     

Superfluorescence from Yb- and Yb–Er-doped phosphotellurite glass fibres

Short length, air-clad, multimode fibres were fabricated using high concentration Yb- and Yb–Er-doped phosphotellurite glass. Superfluorescent light sources are obtained by optically pumping the fibres using a 980 nm laser diode. Ytterbium-doped fibre showed amplified spontaneous emission (ASE) in the 1000–1100 nm wavelength region, whereas Yb–Er-codoped fibre in both 1000–1100 nm (due to Yb³⁺ ions) and 1450–1650 nm (due to Er³⁺ ions) wavelength regions. The ASE spectra from the fibres are compared for different fibre lengths and pump powers. The observed change in the ASE spectral shape and the shift in peak wavelength with the length of the optical fibre is discussed.     

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     

Wideband wavelength tunable modelocked fibre laser over 1557-1607nm

An electronically wavelength tunable modelocked fibre laser operating over a 50 nm range using an all-fibre acousto-optic tunable filter is presented. The tuning range is 1557-1607 nm, for a 70 m long erbium-doped fibre (EDF) with a 270 ppm concentration     

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.