A5067671392- Photonic Crystal and Fiber Optics
- Advanced Fiber Optic Sensors
- Photonic and Optical Devices
- Semiconductor Lasers and Optical Devices
- Advanced Fiber Laser Technologies
- Solid State Laser Technologies
- Optical Network Technologies
- Glass properties and applications
- Phase-change materials and chalcogenides
- Spectroscopy and Laser Applications
- Advanced Photonic Communication Systems
- Spectroscopy Techniques in Biomedical and Chemical Research
- Optical Coherence Tomography Applications
- Advanced Frequency and Time Standards
- Optical Coatings and Gratings
- Laser Material Processing Techniques
- Engineering and Test Systems
- Advanced Optical Sensing Technologies
- Advanced Memory and Neural Computing
- Laser Design and Applications
- Neural Networks and Reservoir Computing
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Optical and Acousto-Optic Technologies
- Mechanical and Optical Resonators
University of Nottingham
2019-2024
Gooch & Housego (United Kingdom)
2011-2022
Gooch & Housego (Greece)
2014
Gooch & Housego (United States)
2012
University of Exeter
2004
JDSU (United States)
2001
Eaton (United States)
2001
JDSU (Canada)
2000
Materials Technology (United Kingdom)
1991-1995
Oclaro (United Kingdom)
1995
We present, to the best of our knowledge, first demonstration mid-infrared supercontinuum (SC) tissue imaging at wavelengths beyond 5 μm using a fiber-coupled SC source spanning 2-7.5 μm. The was generated in tapered large-mode-area chalcogenide photonic crystal fiber order obtain broad bandwidth, high average power, and single-mode output for diffraction-limited performance. Tissue demonstrated transmission selected between 5.7 (1754 cm-1) 7.3 (1370 by point scanning over sub-millimeter...
By choosing pump wavelengths at which excited state absorption does not occur, efficient high gain operation of erbium-doped fibre amplifiers is possible. Practical 532 nm and 980 are identified as optimal, giving gains 1.35dB/mW 2.2dB/mW the two wavelengths, respectively.
A mechanism for phase-matched generation of second-harmonic (SH) light in an optical fibre has been experimentally and theoretically studied. weak non-phase-matched SH signal, created via the quadrupole polarisation, initiates self-writing axially periodic pattern colour centres which is postulated to lead growth a χ (2) grating. The grating (at phase-match period) gives rise at efficiencies 0.5%. spectral bandwidth this 0.24 nm.
We present numerical modeling of mid-infrared (MIR) supercontinuum generation (SCG) in dispersion-optimized chalcogenide (CHALC) step-index fibres (SIFs) with exceptionally high aperture (NA) around one, pumped mode-locked praseodymium-doped (Pr(3+)) fibre lasers. The 4.5um laser is assumed to have a repetition rate 4MHz 50ps long pulses having peak power 4.7kW. A thorough design optimisation was conducted using measured material dispersion (As-Se/Ge-As-Se) and loss obtained fabricated the...
We report the measurement of temperature distribution with an Nd3+ -doped multimode optical fibre. By exploiting temperature-sensitive absorption bands doped-glass core, was measured to accuracy 2°C over range −50°C 100°C. A spatial resolution 15 m a fibre length 140 obtained.
This Letter, to the best of our knowledge, reports mid-infrared fiber lasing beyond 5 µm at room temperature for first time, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msup> <mml:mi mathvariant="normal">C</mml:mi> mathvariant="normal">e</mml:mi> </mml:mrow> <mml:mn>3</mml:mn> <mml:mo>+</mml:mo> </mml:msup> </mml:math> -doped, chalcogenide glass, step index employed in-band pumping with a 4.15 quantum cascade laser. The...
It is shown that large permanent enhancements in second-order optical nonlinearity can be induced germanosilicate fibers (both pure and codoped with phosphorus) by application of a transverse dc electric poling field the presence high-intensity light. The macroscopic inversion symmetry core material broken excitation alignment defect centers. Significant frequency doubling results despite absence phase matching. saturation (with both increasing intensity) this effect investigated.
Laser emission has been observed in a samarium3+-doped silica optical fibre Fabry-Perot-type laser cavity. The is centred on 651 nm and corresponds to stimulated transitions from the 4G5/2 level 6H9/2 level. fluorescence absorption associated with metastable are seen be unusually narrow (3nm FWHM) for trivalent rare earth disordered glass structure. operated CW Q-switched modes when pumped 488 light at room temperature.
Chirped gratings with very broad reflection bandwidths up to 44 nm and high reflectivity have been produced holographically in boron-codoped standard telecommunications fibres which hydrogen-soaked. A 2 wide transmission band has within the by use of an amplitude mask during grating exposure.
Switching in less than 1 ns of an optical signal at 632 nm is demonstrated a m fiber Sagnac interferometer. Full modulation was obtained with pump power 24 W wavelength 532 nm.
A practical realization of a diode pumped actively Q-switched Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> -doped fluoride fiber laser operating near 2.78 μm is reported. For the repetition rate 100 Hz stable 26 ns pulses with an energy 330 μJ and peak power 12.7 kW are demonstrated. The performance tested against variations in pump power, active length.
A spontaneous emission fiber source operating in the mid-infrared (MIR) wavelength range from 3.5 to 8 µm is demonstrated for first time at output power levels of least 1 mW. The a Pr3+-doped selenide chalcogenide, multimode, glass pumped with commercially available laser diodes 1.470 µm, 1.511 and 1.690 µm. This MIR offers viable alternative broadband supercontinuum sources, which are comparatively complex costly. significant molecular sensing applications across biology chemistry,...
Abstract Rare-earth ion doped, silica glass, optical fibre amplifiers have transformed the world by enabling high speed communications and Internet. Fibre lasers, based on rare-earth doped glass fibres, achieve powers are exploited in machining, sensing medical surgery. However, chemical structure of fibres limits wavelength laser operation to < 2.5 µm, which excludes mid-infrared longer range 3–50 µm. doping fluoride glasses enables manufacture lasers up a limiting 3.92 µm wavelength,...
A distributed optical-fibre stress sensor with a measurement path length of 25m and spatial resolution lm is described. The sensor, the first its kind, uses stimulated Raman interaction between counterpropagating pump Stokes waves.
A microchannel was inscribed in the fiber of a ring cavity which constructed using two 0.1% : 99.9% couplers and 10-m loop. Cavity down spectroscopy used to measure refractive index (RI) gels infused into microchannel. The time discloses nonlinear increase with respect RI gel sensitivity up 300 mus/RI unit an resolution 1.4 times10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> obtained.
Abstract In this paper, a highly sensitive water pollutant optical sensor is proposed and analyzed. The suggested consists of photonic crystal fiber with core surrounded by four elliptical holes infiltrated the studied analyte (pure/polluted sample). addition, two gold nanorods are mounted horizontally at inner surfaces horizontal holes. can efficiently detect dissolved pollutants in such as nitric acid ( $${\mathrm{HNO}}_{3}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">...
A new multiwavelength semiconductor laser with singlemode fibre output is reported. The consists of a array which incorporated into an external cavity comprising diffraction grating and loop mirror. This has five wavelength-locked channels fixed separation 2.5 nm. centre wavelength may be tuned over 80
Broadband chirped fibre Bragg filters centred at 980nm and 1480nm with reflectivities as high 99% reflection bandwidths up to 22nm are reported. The have a low transmission loss of <0.5 db between 1.51 1.56μm their application reject recycle unabsorbed pump light from amplifier is demonstrated.
Abstract We demonstrate a maximum gain of 4.6 dB at signal wavelength 5.28 μm in 4.1 resonantly pumped Pr 3+ -doped selenide-based chalcogenide glass fibre amplifier length 109 mm, as well new excited-stated absorption (ESA) wavelengths around 5.5 μm. This work to the best our knowledge is first experimental demonstration mid-infrared (MIR) amplifier. The ESA attributed transition 3 H 6 → ( F 4 , ) after pump 5 μm, which absorbs MIR 5.37, 5.51 and 5.57 so spoils amplifier’s performance these...
A novel external cavity configuration for stable single frequency operation of the semiconductor laser is demonstrated. By using an erbium doped fiber as cavity, longitudinal mode-hopping suppressed, ensuring operation. Employing a 3 m long resolution-limited optical linewidths kHz are obtained.