An original femtosecond Cr<sup>4+</sup>:forsterite laser source associated with a nonlinear optical correlator was used for imaging through scattering media with 1220-nm light. The system, which operates as an ultrafast optical gate by sum-frequency generation in a nonlinear crystal, was able to detect the light reflected from a resolution chart hidden in a turbid medium, at an attenuation of as much as 15 mean free paths. When the object was illuminated with a collimated beam, real-time two-dimensional images were obtained, with a maximum transverse resolution of ∼20 µm.
© 2000 Optical Society of America
(290.1350) Scattering : Backscattering
(290.1990) Scattering : Diffusion
(290.7050) Scattering : Turbid media
(320.2250) Ultrafast optics : Femtosecond phenomena
(320.7110) Ultrafast optics : Ultrafast nonlinear optics
E. Abraham, E. Bordenave, N. Tsurumachi, G. Jonusauskas, J. Oberlé, C. Rullière, and A. Mito, "Real-time two-dimensional imaging in scattering media by use of a femtosecond Cr4+:forsterite laser," Opt. Lett. 25, 929-931 (2000)