High-speed and high-precision chemical-imaging sensor

The scanning-laser-beam chemical-imaging sensor [M. Nakao et al., Sensors and Actuators B, 20 (1994) 119] is a new tool for visualizing the distribution of chemical species. In spite of its high spatial resolution and high sensitivity, its relatively slow operation due to the large number of pixels may restrict its application, especially to real-time observation of chemical processes. In this study, the trade-off relation between the measuring rate and precision of the chemical-imaging sensor is investigated by simulation and experiments. It is shown that an optimized choice of the ratio of the sampling frequency to the light-modulation frequency allows a drastic reduction of the measuring time without much sacrifice of precision.