8 of component B suggests the presence of a temperature independent pseudogap with a magnitude 2Δ$_{PG}$ ≃ 120 meV. The pseudogap is destroyed at a finite fluence in- dicating that it is not a band-structure effect (such as a 120 meV gap at some arbitrary point in the Bril- louin zone). Component C is observed only in the su- perconducting state and corresponds to the relaxation across a T -dependent superconducting gap with a BCS temperature dependence. At high enough pump flu- ence a complete destruction of the superconducting state is observed with the critical optical excitation density U p / k$_{B}$ ≈ 1 . 8 K/Fe which is similar to the value observed in (La,Sr)CuO$_{4}$. ation mechanisms in Sm-1111 and (Ba,K)-122. While behavior in (Ba,K)-122 is consistent with the Rotwarf- Taylor model 27,56 where the anharmonic optical-phonon decay is determining the relaxation time in Sm-1111 the presence of the ungapped electronic subsystem seems to provide a competing relaxation channel. However, only ℏ ω$_{P}$ = 1 . 55 eV was used in (Ba,K)Fe$_{2}$As$_{2}$ so ultrafast pump-probe spectroscopy at different ℏ ω$_{P}$ in 122 sys- tems and measurements in LaFeAsO$_{1}$ − x F x are needed for determination whether some fundamental difference between 1111 and 122 systems is responsible for the dif- ferent relaxation time behavior and marked temperature dependence above T$_{c}$ in Sm-1111. The multicomponent relaxation in SC samples strongly suggest the presence of two relatively weakly coupled electronic subsystems, one exhibiting the SC gap(s) and the other the pseudogap. From the temperature and fluence dependence of photoinduced optical reflec- tivity transients in undoped and near-optimally doped SmFeAsO$_{1}$ − x F x single crystals it is clear that the pres- ence of two electronic subsystems in the superconducting sample is not a result of a simple phase separation. The fact that no relaxation component - such as appears in the SDW phase - is seen in the SC phase appears to rule this out. The presence of two electronic subsystems therefore originates either in an intrinsic phase separation or more likely in the multiband nature of the supercon- ducting iron-pnictides. III. SUMMARY AND CONCLUSIONS Acknowledgments This work has been supported by ARRS (GrantNo.P1- 0040) and the Swiss National Science Foundation NCCR MaNEP. In undoped SmFeAsO a single-exponential relaxation is observed. From the high- T relaxation time the second moment of the Eliashaberg function is determined to be λ 〈 ω $^{2}$〉 = 135 ± 10 meV $^{2}$. The coupling constant λ ≈ 0 . 2 , estimated from this value, is comparable to low- T c super- conductors and cannot explain the high superconducting T c s of these compounds within a single band BCS model. Below T$_{SDW}$ the temperature dependence of the relax- ation indicates appearance of a QP relaxation bottleneck due to opening of a single charge gap at T$_{SDW}$ with a BCS-like temperature dependence and the amplitude of 2Δ$_{SDW}$ /k$_{B}$T$_{SDW}$ ≃ 5 at 4.2 K. A question whether this charge gap is a direct consequence of the SDW formation or due to the structural transition unfortunately cannot be answered from our data. In superconducting SmFeAsO$_{0}$ . $_{8}$F$_{0}$ . 2 three distinct re- laxation components are observed. Components A and B are present in both the superconducting and the nor- mal state. The temperature dependence of the amplitude 1 Y. Kamihara, H. Hiramatsu, M. Hirano, R. Kawamura, H. Yanagi, T. Kamiya, and H. Hosono, Journal of the American Chemical Society 128 , 10012 (2006), URL http://dx.doi.org/10.1021/ja063355c . 2 Y. Kamihara, T. Watanabe, M. Hirano, H. Hosono, et al., J. Am. Chem. Soc 130 , 3296 (2008). 3 Z. Ren, G. Che, X. Dong, J. Yang, W. Lu, W. 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