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Honorary Editor's introduction. Special issue in honour of the 60th birthday of Professor David Hanna FRS
No full textThe idea of pulling together a Cluster of papers in celebration of the 60th birthday of Professor David Hanna FRS was inspired by his award of the European Physical Society Quantum Electronics Prize 2000 for applied aspects. The prize citation recognises David's 'outstanding and numerous contributions to solid-state laser physics and non-linear optics', an evaluation warmly endorsed by those of us who have been lucky enough to work with him. Over the years, David Hanna has made immense personal contributions to the field of quantum electronics and has inspired many students and collaborators to go on to make their own contributions. His influence can be seen in many aspects of the field and those who have worked closely with him have gone on to make significant impacts in the fields of business and academia throughout the world.David Hanna, who was the 1993 recipient of the Max Born Medal and Prize, has served as Deputy Director of the Optoelectronics Research Centre at the University of Southampton since its foundation in 1989. His achievements over this period include major advances in the high-power operation of bulk, fibre and planar guided-wave lasers, and the refinement of the optical parametric oscillator into a versatile practical source. All of these areas are represented in this Cluster, in which many of the contributors are David's students and colleagues, past and present. In Some thoughts on 38 years of lasing David shares his unique perspective on the evolution of this important field of contemporary optics.We hope that the readers of Journal of Physics D: Applied Physics will enjoy sampling the range and depth of topics covered by this tribute to David Hanna. The publication of the Cluster coincides with developments in the board of the Journal where we intend to give greater prominence to developments in the field of what has become known as Photonics
Frequency-modulation mode-locking of a Nd<sup>3+</sup>-doped fibre laser
No full textFrequency-modulation mode locking of a Nd3+-doped fiber laser operating at 1.09 µm using a bulk phase modulator is reported. The resulting pulses have a 20-psec duration (FWHM) and a peak power of 1 W. A least-squares fit to the second-harmonic-intensity autocorrelation trace and the time-bandwidth product of 0.30 ± 0.04 suggest that the pulses are bandwidth limited with a sech2-type profile
Diode-pumped FM modelocked fibre laser with coupled cavity bandwidth selection
No full textA diode-laser-pumped Nd3+-doped fibre laser has been actively mode-locked using an integrated fibre phase modulator. Pulses with a sub-80 ps duration are observed at a repetition rate of 417 MHz. Near bandwidth-limited operation is achieved by restricting the laser bandwidth by feedback off a diffraction grating in an external coupled cavity. Low intracavity losses support a submilliwatt laser threshold and a slope efficiency in excess of 48%
Frequency modulated mode-locked fiber laser with an integrated fiber phase modulator
No full textA Nd3+-doped fiber laser has been FM modelocked by two means: 20-ps pulses were obtained with a bulk phase modulator. Detuning the modulation frequency induced FM operation which broadened the laser bandwidth to 57 GHz. An integrated fiber phase modulator produced 80-ps pulses. Low intracavity losses led to submilliwatt thresholds and slope efficiencies in excess of 45%
Mode-locked fiber laser with a fiber phase modulator
No full textFM mode-locked operation of a single-mode Nd3+-doped fiber laser has been achieved with an integrated fiber phase modulator. The technique permits a low-loss cavity configuration, resulting in low threshold and high slope efficiency. Pulses of ~200psec duration are observed at a repetition rate of 417 MHz with an average output power of 15 mW
Optical chaos and hysteresis in a laser-diode pumped Nd doped fibre laser
No full textModulated pumping of a Nd3+doped silica monomode fibre laser has been investigated experimentally. For small modulation depths the laser exhibits a resonance at the relaxation oscillation frequency, providing pulses of a few microseconds duration at a repetition rate in the region of 10 kHz, dependent on the average pump level above threshold. As the pump modulation depth is increased, hysteresis is observed as a function of modulation frequency, along with optical bistability. For further increase in modulation depth, optical chaos and period doubling are observed. Gain-switching has also been demonstrated
Q-switched operation of a neodymium-doped monomode fibre laser
No full textQ-switched operation of a neodymium-doped monomode fibre laser at 1.08 µm has been demonstrated. An intracavity acousto-optic modulator was used to switch pulses of 200 ns duration and 8.8 W peak power at a repetition rate of 100 Hz
Frequency modulated mode-locked fibre laser with bulk and integrated fibre phase modulators
No full textQ-switching and modelocking of neodymium-doped monomode fibre laser at 1.08µm and 906nm
No full textThere has recently been great interest in the use of rare earth-doped monomode optical fibre in high gain laser systems. The monomode fibre geometry confers a low threshold for laser operation, so that compact and highly efficient devices using semiconductor diode laser pumping can be constructed. Moreover the strong inhomogeneous broadening of the rare earth transitions in the glass fibre offers the possibility of broadband tunable operation
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