arXiv subjects

Jong H. Chow

Publications and source records attributed to Jong H. Chow.

3 recordsLinked to original sources

arXiv2005

Demonstration of a passive sub-picostrain fiber strain sensor

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.

physics.optics↗

arXiv2004

Interrogation of a fiber Fabry-Perot sensor by current modulation of a diode laser

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.

physics.optics↗

arXiv2004

Phase-sensitive interrogation of fiber Bragg grating resonators for sensing applications

We discuss a phase-sensitive technique for remote interrogation of passive Bragg grating Fabry-Perot resonators. It is based on Pound-Drever-Hall laser frequency locking, using radio-frequency phase modulation sidebands to derive an error signal from the complex optical response, near resonance, of a Fabry-Perot interferometer. We examine how modulation frequency and resonance bandwidth affect this error signal. Experimental results are presented that demonstrate when the laser is locked, this method detects differential phase shifts in the optical carrier relative to its sidebands, due to minute fiber optical path displacements.

physics.optics↗