  We demonstrate a fiber Fabry-Perot (FFP) sensor capable of detecting
sub-picostrain signals, from 100 Hz and extending beyond 100 kHz, using the
Pound-Drever-Hall frequency locking technique. A low power diode laser at 1550
nm is locked to a free-space reference cavity to suppress its free-running
frequency noise, thereby stabilizing the laser. The stabilized laser is then
used to interrogate a FFP where the PDH error signal yields the instantaneous
fiber strain.
