Heat transport imaging in the spin-ladder compound Ca9La5Cu24O41

All-optical heat transport imaging on the spin-ladder compound Ca9La5Cu24O41 is presented. A 'time-of-flight' principle is discussed along with its experimental veri. cation which can be used to measure the bulk thermal diffusion constant. The results of the thermal imaging experiments clearly demonstrate anisotropic magnon heat transport. (C) 2008 Elsevier B.V. All rights reserved.