  The in-plane London penetration depth, $\lambda(T)$, was measured in single
crystals of the iron-chalcogenide superconductors
Fe$_{1.03}$(Te$_{0.63}$Se$_{0.37}$) and Fe$_{1.06}$(Te$_{0.88}$S$_{0.14}$) by
using a radio-frequency tunnel diode resonator. As is also the case for the
iron-pnictides, these iron-chalcogenides exhibit a nearly quadratic temperature
variation of $\lambda(T)$ at low temperatures. The absolute value of the
penetration depth in the $T \to 0$ limit was determined for
Fe$_{1.03}$(Te$_{0.63}$Se$_{0.37})$ by using an Al coating technique, giving
$\lambda(0)\approx560 \pm 20$ nm. The superfluid density
$\rho_s(T)=\lambda^2(0)/\lambda^2(T)$ was fitted with a self-consistent two-gap
$\gamma-$model. While two different gaps are needed to describe the full-range
temperature variation of $\rho_s(T)$, a non-exponential behavior at low
temperatures requires additional factors, such as scattering and/or significant
gap anisotropy.
