Multiwavelength highly transient stimulated Raman scattering on dual Raman modes in Sr(MoO₄)_0.8(WO₄)_0.2 and...

For the first time to our knowledge, multiwavelength, highly transient, single-pass stimulated Raman scattering with a low wavelength spacing on dual (stretching and bending) Raman modes in Sr(MoO₄)_0.8(WO₄)_0.2 and Sr(MoO₄)_0.4(WO₄)_0.6 solid solutions in a range of 1000-1300 nm (transparence window of biological tissue) under ultrafast chirped pulse laser pumping is comparatively investigated in the interests of multicolor two-photon imaging of a living tissue. For both the solid solutions, the optimum range (1-5 ps) of chirped pump pulse durations for multiwavelength Raman conversion on dual Raman modes was wider than for SrMoO₄ (2-3 ps) due to the higher integral cross section of the bending Raman mode. Higher efficient SRS conversion took place at negative chirping of the pump pulse with its stretching from 0.25 ps up to 5 ps due to the compensation of a positive chirp caused by nonlinear phase modulation with total Raman conversion efficiency of up to 36% for Sr(MoO₄)_0.8(WO₄)_0.2 and 49% for Sr(MoO₄)_0.4(WO₄)_0.6. The highest number (five) of Stokes components in the desired range (1000-1300 nm) was observed in the optimum Sr(MoO₄)_0.4(WO₄)_0.6 solid solution, which has the Raman modes with comparable intensities.