Wavelength monitoring devices for use in optical fiber sensors

Summary form only given. A two-element, GaAs quantum well photodetector has been demonstrated to act as a sensitive wavelength monitor for use in optical fiber Bragg grating strain sensors. The sensors are being developed to provide an internal sensing system for new-generation civil engineering structures, now termed smart structures. Two identical quantum well waveguide photodiodes are fabricated in-line on a shared rib waveguide channel. Input light is delivered to the cleaved input facet of the first detector and must pass through it to reach the second detector.