  We present a method for remote interrogation of passive fiber Bragg grating
Fabry-Perot resonators, employing current modulation of the diode laser source.
With the presence of both RF amplitude and frequency modulation, it is a
variant of the ultra-sensitive Pound-Drever-Hall laser frequency locking
technique. We demonstrate that current modulation and interferometric
demodulation removes the need for a phase modulator in the sensing
architecture.
