New colours with poled fibres
Researchers from the Optoelectronics Research Centre (ORC) at the University of Southampton, UK, have for the first time demonstrated broad range tuning of the wavelength of light generated through nonlinear optical processes in silica fibres. Such processes would normally be forbidden in glass because of its inversion symmetry, and would therefore be restricted to nonlinear crystals. The team has used a special technique, known as poling, to break the symmetry of the glass, creating the opportunity to develop a new class of all-fibre devices for frequency conversion and phase manipulation.
All-fibre wavelength conversion by Periodically Poled Silica Fibres (PPSF) ensures seamless integration with fibre lasers and avoids the use of bulk nonlinear optical crystal. Tuning of light is achieved through axial compression of the periodically poled fibre, enabling access to new wavelengths which are generally not possible in fibre lasers.
A longer interaction length, lower losses of light and high resilience to optically-induced damage make the PPSF an intriguing candidate for frequency conversion in fibre lasers. The tunability feature discovered by the team adds to the functionality of the PPSF.
‘Using the tuning mechanism from fibre Bragg gratings technology, we have managed to achieve the largest second-harmonic wavelength tuning range seen so far for single quasi-phase-matched periodically poled devices,’ explains Albert Canagasabey, a member of the team. ‘This discovery is significant because it improves functionality of the PPSF and allows access to wavelengths within fibres that weren’t accessible before, giving us a platform to generate new wavelengths which can be used in medical, industrial and sensing applications.’
This groundbreaking research on poled fibres recently published by the team has a dedicated paragraph in the ‘research highlights’ section of Nature Photonics.
The ORC has long been a world leader in fibre Bragg gratings technology which is used in many of the ORC’s projects within the telecommunications, sensors, short pulse and fibre laser areas. This most recent work is part of a joint project between the Fibre Bragg Gratings Group, led by Dr Morten Ibsen, and the Physical Optics Group, led by Prof Peter Kazansky.
Notes for editors
- The paragraph in the ‘research highlights’ section of Nature Photonics can be found at http://www.nature.com/nphoton/journal/v1/n7/full/nphoton.2007.101.html
- The paper highlighted in Nature Photonics is the following: A.Canagasabey, C.Corbari, Z.Zhang, P.G.Kazansky, M.Ibsen "Broadly tunable second-harmonic generation in periodically poled silica fibers", Optics Letters 2007 Vol.32(13) pp.1863-1865
- The Optoelectronics Research Centre at the University of Southampton is one of the largest university-based research groups entirely devoted to optoelectronics in the world, and has maintained a position at the forefront of photonics research for over four decades. Its long and well established track record in the fields of optical fibre, lasers, waveguides, devices and optoelectronic materials has fostered innovation, enterprise, cross-boundary and multi-disciplinary activities. It has built strong links with industry, research institutions and universities around the world, from informal collaborations to large-scale funding. Several spin out companies, including Southampton Photonics Inc, Stratophase Ltd, Mesophotonics Ltd and ChG Southampton Ltd, have commericalised the fruits of ORC research; while its extensive outreach programme has brought lasers and optical fibres into schools across the country.
Albert Canagasabey, Optoelectronics Research Centre, (tel: 023 8059 4530, email: firstname.lastname@example.org)
Marketing Officer, Optoelectronics Research Centre, University of Southampton, (Tel: 023 8059 3877, email: email@example.com)