Spatially resolved holographic measurement of the thermal diffusivity in liquids

Phase gratings are recorded holographically with nanosecond light pulses by the interference of two plane waves in colored liquid samples using the thermooptic effect. The samples consist of toluene and distilled water which are immiscible and have different thermal conductivities. The exponential decay of the gratings caused by the thermal conductivity is monitored by diffraction of continuous wave light, and the thermal diffusivity is determined. Scanning of the read-out beam provides spatial resolution