Measurements of plant growth by statistical interferometry : Influence of air pollution on plants

The statistical interferometry proposed and developed by the authors has been applied to measure the growth of plants, aiming at investigating the influence of environmental conditions on plants. This method utilizes the statistical properties of a fully developed speckle field and has the advantage of a simple optical system to achieve measurements with an extremely high accuracy. In experiments aimed at determining the validity of this method, the growth speeds of plants were measured under the exposure of ozone, which is the main substance of a photochemical oxidant. It has been clearly demonstrated that the statistical interferometry has a high sensitivity for monitoring the growth of plants on a nanometer scale with a high temporal resolution of a second scale