ilAbstract. We measured the response of short FBGs to a weak planar shock wave. The combined effect of the Photo-Elastic effect and the FBG strain was estimated theoretically depending on its orientation with respect to shock front (for 1550 nm FBG, parallel: 0.9 nm/kbar, perpendicular: -1.4 nm/kbar). The experimental results imply that the FBG/fibre survives for more than 1 μs at 5 kbar shock stress, and that our assumptions about the FBG behaviour under dynamic loading are valid, though more work is needed to fully quantify the effect.

The recovery of metastable structures formed at high pressure has been a long-standing goal in the field of condensed matter physics. While laser-driven compression has been used as a method to generate novel structures at high pressure, to date no high-pressure phases have been quenched to ambient conditions. Here we demonstrate, using in situ x-ray diffraction and recovery methods, the successful quench of a high-pressure phase which was formed under laser-driven shock compression. We show that tailoring the pressure release path from a shock-compressed state to eliminate sample spall, and therefore excess heating, increases the recovery yield of the high-pressure ω phase of zirconium from 0% to 48%. Our results have important implications for the quenchability of novel phases of matter demonstrated to occur at extreme pressures using nanosecond laser-driven compression.

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