Stimulated Raman scattering in an ethanol core microstructured optical fiber.

We show that high efficiency stimulated Raman scattering can be obtained using hollow core photonic crystal fiber with the core filled with a low refractive index nonlinear liquid. This new architecture opens new perspectives in the development of nonlinear functions as any kind of nonlinear liquid media can now be used to implement them, with original properties not accessible with silica core fibers.

Efficient laser operation of an Yb:S-FAP crystal at 985 nm.

We have obtained three-level cw laser operation at 985 nm with a Yb-doped S-FAP bulk crystal pumped by a Ti:sapphire laser. An output power of 250 mW for an incident pump power of 1.45 W has been achieved, which is the highest cw output power ever obtained, to our knowledge, at this wavelength with a Yb-doped crystal. The experimental results are in good agreement with the numerical model that we have developed.

Improvement of the spatial beam quality of laser sources with an intracavity Bragg grating.

We demonstrate a novel method for improvement of spatial beam quality by use of the angular selectivity of a thick phase grating inserted into various laser cavities. Preliminary experiments with an intentionally degraded beam from a Nd:YVO4 laser have enhanced beam propagation factor M2 by a factor of 4.5. Operation with a broad-area laser diode in an external cavity with a thick grating was achieved. We obtained 100 mW of cw power in a beam with an M2 of 1.3. Moreover, a reduction of the output spectrum by as much as a factor of 3.8 was obtained.

Continuous-wave diode-pumped solid-state laser with an intracavity fiber Bragg grating.

We demonstrate the feasibility of a new concept of laser that benefits from both fiber and laser crystals: a cw diode-pumped solid-state laser with an intracavity fiber Bragg grating as the output coupler. The design of the laser cavity and the experimental demonstration are both described. Several applications are mentioned.