6533b833fe1ef96bd129befc

RESEARCH PRODUCT

Fiber-based light source for biomedical applications

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This manuscript presents the work done concerning the development of a light source used for biomedical imaging and more particularly for coherent Raman scattering imaging. In fact an efficient broadcasting of these ones is hampered by the need of two synchronized and wavelength shifted pulses. As so, the handiness and frequency conversion capabilities of nonlinear fiber optics are used to circumvent this technological lock. First of all, an easy wavelength tunable source is set by the use of the self-shifting in optical frequency of a soliton. A study of the main fiber parameters lead to shifts of 320 to more than 500 nm which allows interesting molecular resonances imaging (≈ 1000-4000 cm-1). Two applications of this shift are also reported. Then, the second pulse sees its spectral width reduced from 70 to 10 cm-1 by spectral compression, which consists in a "loss-less frequency regrouping", in order to obtain a proper spectral resolution. Finally, the developed source is validated by acquiring CARS spectra of different reference solvents and for different resonances (850 to 1750 cm-1). An evolution of this source to allow other imaging techniques is proposed, as well as a quasi-all-fibered source exploiting the principles addressed during this thesis work