Extended-range, low coherence dual wavelength interferometry using a superfluorescent fibre source and chirped fibre Bragg gratings

We describe an all-fibre, passive scheme for making extended range interferometric measurements based on the dual wavelength technique. The coherence tuned interferometer network is illuminated with a single superfluorescent fibre source at 1.55 µm and the two wavelengths are synthesised at the output by means of chirped fibre Bragg gratings. We demonstrate an unambiguous sensing range of 270 µm, with a dynamic range of 2.7 × 10 5.

Actively modelocked dual-wavelength fibre laser with ultra-low inter-pulse-stream timing jitter

We demonstrate a novel dual-wavelength erbium-fiber laser that uses a single nonlinear-optical loop mirror modulator to simultaneously modelock two cavities with chirped fiber Bragg gratings as end mirrors. We show that this configuration produces synchronized soliton pulse trains with an ultra-low RMS inter-pulse-stream timing jitter of 620 fs enabling application to multiwavelength systems at data rates in excess of 130 Gb/s.

Improved supercontinuum generation by dispersion tuning and dual wavelength pumping

Supercontinuum generation in ultra-long Raman fibre laser cavities is compared for a range of fibre dispersions in the anomalous and normal regimes. For normal dispersion improved performance and efficiency is achieved using dual wavelength pumping.

Single- and dual-wavelength switchable erbium-doped fiber ring laser based on intracavity polarization selective tilted fiber gratings

We propose and demonstrate a single- and dual-wavelength switchable erbium-doped fiber laser (EDFL) by utilizing intracavity polarization selective filters based on tilted fiber gratings (TFGs). In the cavity, one 45° TFG functions as an in-fiber polarizer and the other 77° TFG is used as a fiber polarization dependent loss (PDL) filter. The combined polarization effect from these two TFGs enables the laser to switch between the single- and the dual-wavelength operation with a single-polarization state at room temperature. The laser output at each wavelength shows an optical signal-to-noise ratio (OSNR) of >60 dB, a side mode suppression ratio (SMSR) of >50 dB, and a polarization extinction ratio of ~35 dB. The proposed EDFL can give stable output under laboratory conditions.

Transversal loading sensor based on tunable beat frequency of a dual-wavelength fiber laser

Microwave signal generation by using the photonic beating from a phase-shift fiber Bragg grating (PS-FBG)-based dual-wavelength laser is proposed and experimentally demonstrated. The dual-wavelength laser is formed by a linear cavity, in which a PS-FBG is used as a dual-wavelength selective component. Transversal loading on the PS-FBG enhances the birefringence of the optical fiber and consequently makes the transmission peak of the PS-FBG splitting into two sharp transmission peaks of orthogonal polarizations. The wavelength spacing between the two transmission peaks increases with the transversal loading on the PS-FBG, thus making the polarization beating frequency increase. This property is exploited in a transversal loading sensor.

Dual-wavelength, ultralong Raman laser with Rayleigh-scattering feedback

We present experimental demonstration of a 200-km-long, dual-wavelength Raman laser utilizing two slightly different-wavelength fiber Bragg gratings, one on each side of the fiber span. The obtained results clearly prove the generation of two independent Raman lasers with a distributed “random” Rayleigh scattering mirror forming a cavity together with each of the individual fiber Bragg grating reflectors.

Extended range interferometry using a coherence tuned synthesised dual wavelength technique with multimode fibres

We describe in the letter a technique for making extended-range interferometric measurements with a coherence multiplexed system by means of a variation on the dual-wavelength technique. The interferometer is illuminated with a single source and the two wavelengths are synthesised at the output by means of an interference filter.

Alternate wavelength-switching in a dual-wavelength mode-locked fibre laser

We report a stable, dual-wavelength mode-locked fiber laser at 1 GHz with a wavelength spacing of 0.7 nm. Alternate switching between single and dual wavelength output was also achieved by simple adjustment of the pump power.

Dual wavelength Q-switched cascade laser

A diode-cladding-pumped dual wavelength Q-switched Ho3+ -doped fluoride cascade fiber laser operating in the mid-infrared is demonstrated. Stable pulse trains from the 5|6 -> 5|7 and 5|7 -> 5|8 laser transitions were produced, and the µs-level time delay between the pulses from each transition was dependent on the pump power. At maximum pump power and at an acousto-optic modulator repetition rate of 25 kHz, the 5|8 -> 5|7 transition pulse operated at 3.005 µm, a pulse energy of 29 µJ, and a pulse width of 380 ns; the 5|7 -> 5|8 transition pulse correspondingly produced 7 µJ pulse energy and 260 ns pulse width at 2.074 µm. To the best of our knowledge, this is the first demonstration of a Q-switched fiber laser operating beyond 3 µm.

Actively modelocked dual-wavelength fibre laser with ultra-low inter-pulse-stream timing jitter

We demonstrate a novel dual-wavelength erbium-fiber laser that uses a single nonlinear-optical loop mirror modulator to simultaneously modelock two cavities with chirped fiber Bragg gratings as end mirrors. We show that this configuration produces synchronized soliton pulse trains with an ultra-low RMS inter-pulse-stream timing jitter of 620 fs enabling application to multiwavelength systems at data rates in excess of 130 Gb/s. © 1995 IEEE

Extended-range, low coherence dual wavelength interferometry using a superfluorescent fibre source and chirped fibre Bragg gratings

We describe an all-fibre, passive scheme for making extended range interferometric measurements based on the dual wavelength technique. The coherence tuned interferometer network is illuminated with a single superfluorescent fibre source at 1.55 μm and the two wavelengths are synthesised at the output by means of chirped fibre Bragg gratings. We demonstrate an unambiguous sensing range of 270 μm, with a dynamic range of 2.7 × 105.

Improved supercontinuum generation by dispersion tuning and dual wavelength pumping

Supercontinuum generation in ultra-long Raman fibre laser cavities is compared for a range of fibre dispersions in the anomalous and normal regimes. For normal dispersion improved performance and efficiency is achieved using dual wavelength pumping.

Actively mode-locked tunable dual-wavelength erbium-doped fibre laser

Abstract—We report an actively mode-locked tunable dual-wavelength erbium-doped fiber laser that uses parallel amplifiers in order to minimize gain cross-saturation effects. We obtain extremely stable, room-temperature dual-wavelength operation at a modulator drive frequency of 1035.38 MHz (corresponding pulsewidths of 115 and 130 ps). Furthermore, we can independently tune the power and wavelength of each lasing output signal without affecting overall output stability. In particular, we achieve a wavelength separation as narrow as 0.3 nm.

Stable dual-wavelength oscillation of an Er-doped fiber ring laser at room temperature

We propose a simple Er-doped fiber laser configuration for achieving stable dual-wavelength oscillation at room temperature, in which a high birefringence fiber Bragg grating was used as the wavelength-selective component. Stable dual-wavelength oscillation at room temperature with a wavelength spacing of 0.23 nm and mutually orthogonal polarization stages was achieved by utilizing the polarization hole-burning effect. An amplitude variation of less than 0.7 dB over an 80 s period was obtained for both wavelengths.

Stable dual-wavelength oscillation of an erbium-doped fiber ring laser at room temperature

We propose a simple Er-doped fiber laser configuration for achieving stable dual-wavelength oscillation at room temperature, in which a high birefringence fiber Bragg grating was used as the wavelength-selective component. Stable dual-wavelength oscillation at room temperature with a wavelength spacing of 0.23nm and mutually orthogonal polarisation states was achieved by utilising the polarisation hole burning effect. An amplitude variation of less than 0.7dB over 80s period was obtained for both wavelengths.