The Optoelectronics Research Centre at the University of Southampton, UK is claiming a research breakthrough. It has demonstrated broad range tuning of the wavelength of light generated through nonlinear optical processes in silica fibres.
The team used a 'poling' technique to break the symmetry of the glass, which creates the opportunity to develop a new class of all-fibre devices. These would be suitable for frequency conversion and phase manipulation.
Tuning of light through Periodically Poled Silica Fibres (PPSF) is achieved, says the University, through axial compression of the periodically poled fibre. This enables access to new wavelengths, which are generally not possible in fibre lasers.
'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,' explained Albert Canagasabey, a member of the research team.
'This discovery is significant,' he added, '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.'