Figure 6.

A schematic of the experimental system of SIT. A schematic of the experimental system of SIT (A) used for measuring plant growth placed in an O₃ chamber with a photo of the real system on an optical bench (B). Third or fourth leaf was stably fixed using a sample holder (C) with precaution taken to avoid any damage to the leaf. The leaf length was about 15 to 20 cm. The probing points on the leaf were set to be around 4 cm from the apex of the leaf. The distance d between the points of illumination on the leaf was set to be 3 mm, and d can be adjusted by moving the prism P2 along the optical axis. The CCD camera was placed at a distance of 83 mm from the probing area, and the speckle interference patterns (A) were continuously recorded. Here, the notations indicate, NDF: neutral density filter, PZT: piezoelectric transducer, P1 and P2: prisms to generate two parallel probing beams, θ: angle between the probing and observing directions.