Wavelength-swept laser sources with broad wavelength tunability and narrow instantaneous linewidth in the two-micron band have potential applications in a number of areas, including spectroscopic characterisation and optical coherence tomography (OCT). The use of OCT for non-invasive investigation of paintings to provide the information necessary for effective restoration and to aid conservation is one example of an emerging application where operation in two-micron band brings the advantage of increased penetration depth due to lower loss in commonly used pigments compared to the situation at near-infrared wavelengths. Tm-doped silica fibre lasers provide an efficient way to access the relevant wavelength region due to the wide emission line that extends from ~1700 nm to ~2100 nm. Unfortunately, wavelength tuning across the entire emission band with a single fibre gain stage is extremely difficult due to the combination of varying quasi-three-level character as a function of wavelength and gain saturation due to short wavelength amplified spontaneous emission. In order to access the full emission bandwidth potential of Tm-doped fibres, a different approach must be employed with two or more fibre gain stages and with each gain stage tailored to provide emission in complementary bands.

© 2013 IEEE

PDF Article


You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
Login to access OSA Member Subscription