  Waves play an important role in the heating of solar atmosphere, however,
observations of wave propagation and damping from the solar photosphere to
corona through chromosphere and transition region are very rare. Recent
observations have shown propagation of 3-min slow magnetoacoustic waves (SMAWs)
along fan loops from the solar photosphere to corona. In this work, we
investigate the role of area divergence and frequencies on the damping of SMAWs
propagating from the photosphere to the corona along several fan loops rooted
in the sunspot umbra. We study the Fourier power spectra of oscillations along
fan loops at each atmospheric height which showed significant enhancements in
1--2 min, 2.3--3.6 min and 4.2--6 min period bands. Amplitude of intensity
oscillations in different period bands and heights are extracted after
normalizing the filtered light curves with low-frequency background. We find
damping of SMAW energy flux propagating along the fan loop 6 with damping
lengths ~170 km and ~208 km for 1.5-min and 3-min period bands. We also show
the decay of total wave energy content with height after incorporating area
divergence effect, and present actual damping of SMAWs from photosphere to
corona. Actual damping lengths in this case increases to ~172 km and ~303 km
for 1.5-min and 3-min period bands. All the fan loops show such increase in
actual damping lengths, and thus highlight the importance of area divergence
effect. Results also show some frequency-dependent damping of SMAW energy
fluxes with height where high-frequency waves are damped faster than
low-frequency waves.
