A5018599767- Advanced Fiber Laser Technologies
- Photonic and Optical Devices
- Optical Network Technologies
- Advanced Fiber Optic Sensors
- Semiconductor Lasers and Optical Devices
- Advanced Photonic Communication Systems
- Solid State Laser Technologies
- Laser-Matter Interactions and Applications
- Laser Material Processing Techniques
- Photonic Crystal and Fiber Optics
- Semiconductor Quantum Structures and Devices
- Photorefractive and Nonlinear Optics
- GaN-based semiconductor devices and materials
- Advanced Optical Network Technologies
- Laser Design and Applications
- Optical Coatings and Gratings
- Quantum optics and atomic interactions
- Plasmonic and Surface Plasmon Research
- Metamaterials and Metasurfaces Applications
- Advanced Measurement and Metrology Techniques
- Power System Optimization and Stability
- Magnetic properties of thin films
- Force Microscopy Techniques and Applications
- Magnetic Properties and Applications
- Advanced Antenna and Metasurface Technologies
Aston University
2001-2020
University of Bristol
1997-2005
Russian Academy of Sciences
1992-2005
Prokhorov General Physics Institute
1994-2002
University of Southampton
1997
Fiber Optics Research Center
1995
Vavilov Institute of General Genetics
1990-1992
Direct, point-by-point inscription of fibre Bragg gratings by infrared femtosecond laser is reported for the first time. Gratings to third order have been produced in non-photosensitised, standard telecommunication and dispersion shifted fibre.
Depressed cladding waveguides have been formed in laser crystals by a tightly focused beam of femtosecond laser. A based on depressed waveguide neodymium-doped YAG crystal has demonstrated for what is believed to be the first time.
Direct, point-by-point inscription of fibre Bragg gratings by an infrared femtosecond laser has been reported recently. Response these to annealing at temperatures in the range 500 1050°C is studied for first time. Gratings inscribed lasers were thermally stable up 900°C, representing a significant improvement comparison with 'common', UV-inscribed, gratings. Annealing 700°C increased grating reflectivity.
Inscription of fiber Bragg gratings through the coating a nonphotosensitized standard telecommunication is demonstrated for what believed to be first time. Highly reflective were produced by direct point-by-point writing with an infrared femtosecond laser. The length presented ranged from 5 26 mm. technique does not require special coating, as coatings are transparent radiation. improves mechanical strength processed segment fiber.
A femtosecond laser inscription technique is proposed for the fabrication of a fiber grating directly into nonphotosensitive gain fiber. distributed Bragg reflector realized in conventional, untreated Er:Yb-codoped as an illustration. Robust, single-mode, single-polarization operation at temperatures excess 600 degrees C further achieved without compromising performance. nonlinear, thermally induced wavelength shift also observed elevated temperatures.
The structure of fiber Bragg gratings inscribed point-by-point by an infrared femtosecond laser is studied quantitative phase microscopy. Results show that these present a central region with depressed refractive index surrounded outer corona increased index. profile suggests the presence microvoids embedded in core
A direction-sensitive bend sensor in standard singlemode fibre is demonstrated for the first time based on an axially-offset Bragg grating, directly written by infrared femtosecond laser.
Femtosecond pulse amplification in Er3+-doped single-mode optical fibres has been experimentally investigated. The effect of amplified compression from 80 to 55 fs observed. energy was evaluated as 5 nJ. Maximum gain for the signal 26 dB.
A long period grating (LPG) written in a standard optical fibre was modified by using femtosecond laser to induce an asymmetric change the cladding's refractive index. This device produced blue and red wavelength shifts depending on orientation of applied curvature, with maximum sensitivities −1.6 nm m +3.8 m, suggesting that this type LPG may be useful as shape sensor.
A femtosecond laser has been used to asymmetrically modify the cladding of fiber containing long-period gratings. Following modification, devices in single-mode are shown be capable sensing magnitude and direction bending one plane by producing blue red wavelength shifts depending upon orientation bend. The resulting curvature sensitivities were -1.62 +3.82 nmmiddotm. Devices have also produced using an elliptical core study effects modification on two polarization eigenstates. applied fast...
High-quality femtosecond pulse generation from a 1.5 µm gain-switched DFB laser diode in compact nonlinear compressor based on dispersion-imbalanced fibre loop mirror is reported. An overall compression ratio of 80 achieved, resulting near-transform-limited pulses with negligible tails and duration 270 fs.
We report a novel tunable dispersion compensator (TDC) based on all-fiber distributed Gires-Tournois etalons (DGTE), which is formed by overlapped chirped fiber gratings. Two DGTEs of opposite slope work together to generate periodical profile. The demonstrated TDCs have the advantages multichannel operation, extremely low group-delay ripple, loss, and cost.
A 13-wavelength channel 10-GHz pulse source is demonstrated using a novel scheme incorporating dispersion-imbalanced fiber loop mirror and an arrayed waveguide grating. The output high-quality pulses are 5 ps wide with the pedestal suppression in excess of 25 dB.
The transmission of a 10-Gb/s data stream was demonstrated experimentally over practically unlimited distance in standard single-mode fiber system using nonlinear optical loop mirrors as simple in-line 2R regenerators. Error-free propagation 100 000 km has been achieved with terrestrial amplifier spacing.
Improvement of the signal quality from 10 GHz directly-modulated sources and crosstalk suppression in an 80 Gbit/s OTDM system are demonstrated for first fime by means nonlinear switching a dispersion-imbalanced fibre loop mirror (DILM).
Subpicosecond optical pulses are generated by passive modelocking in bulk active layer InGaAsP semiconductor lasers under CW pumping. The saturable absorber regions formed deep implantation of heavy ions into the diode facets. Optical with 0.64 ps width realised at 110 GHz repetition rate without using any external AC sources. No changes spectra and autocorrelation traces were observed after 50 h operation.
An investigation into the emission and degradation characteristics of GaInN multiquantum well lasers driven by short, high current pulses for both time spectral domains is presented. Sub-nanosecond optical with peak powers exceeding 450 mW gain-switched shorter than 50 ps have been generated.
Observation of autosoliton propagation in a dispersion-managed optical transmission system controlled by in-line nonlinear fiber loop switches is reported for what believed to be the first time. The based on strong dispersion map with large amplifier spacing. Operation at rates 10 and 40 Gbits/s demonstrated.
The suppression of interchannel interferometric crosstalk and reduction extinction-ratio induced power penalty have been demonstrated by means nonlinear switching in a dispersion-imbalanced fibre loop mirror (DILM).
A direction-sensitive bend sensor in standard single-mode fiber is demonstrated for the first time based on an axially-offset Bragg grating, directly written by infrared femtosecond laser.
Signal quality enhancement and interferometric noise suppression have been demonstrated by nonlinear filtering in a dispersion imbalanced loop mirror. The filter improves the signal extinction ratio more then 10 dB simultaneously increases acceptable level 15 dB. improvement is constant throughout wide wavelength range of 28 nm within C-band erbium-doped fiber amplifier region.
Controllable, spatially selective treatment of glass-covered amorphous magnetic wires by laser irradiation is demonstrated. Local annealing an argon has resulted in the formation weakly interacting heterogeneous structures with different properties. Two large and stable Barkhausen jumps were detected magnetization reversal high positive magnetostriction treated portions 200 μm 0.5 cm. The local negative magnetostrictive modified wire magnetoimpedance: maximum impedance plot flattens working...
We present recent results on experimental micro-fabrication and numerical modeling of advanced photonic devices by means direct writing femtosecond laser. Transverse inscription geometry was routinely used to inscribe modify based waveguiding structures. Typically, standard commercially available fibers were as a template with pre-fabricated waveguide. Using direct, point-by-point infrared laser, range fiber-based fabricated including Fiber Bragg Gratings (FBG) Long Period (LPG). Waveguides...