Novel Optical Fiber‐Based Gauge for Measuring Transient Pressures

While methods for determining transient pressures in shocked condensed matter are available, the need has arisen for new gauges whose quality of data, ease of use, and cost make them more appropriate for studying underwater shocks. A novel optical technique for measuring transient pressures in water or other fluids is being developed. One end of an optical fiber is submerged in the fluid of interest, allowing remote operation using a laser light source. The intensity of reflected light from the tip can be related to the optical properties of the fluid at the fiber/fluid interface and thus the pressure experienced by the fluid at a given time. This novel method has the benefits of avoiding electrical interference, permitting fast time resolution, and requiring only a photodiode and oscilloscope as detection electronics. Application of this gauge to studies of shock compression of water produced by detonation of energetic materials will be presented.