Ultra Small Integrated Optical Fiber Sensing System

Abstract

This paper introduces a revolutionary way to interrogate optical fiber sensors based on fiber Bragg gratings (FBGs) and to integrate the necessary driving optoelectronic components with the sensor elements. Low-cost optoelectronic chips are used to interrogate the optical fibers, creating a portable dynamic sensing system as an alternative for the traditionally bulky and expensive fiber sensor interrogation units. The possibility to embed these laser and detector chips is demonstrated resulting in an ultra thin flexible optoelectronic package of only 40 μm, provided with an integrated planar fiber pigtail. The result is a fully embedded flexible sensing system with a thickness of only 1 mm, based on a single Vertical-Cavity Surface-Emitting Laser (VCSEL), fiber sensor and photodetector chip. Temperature, strain and electrodynamic shaking tests have been performed on our system, not limited to static read-out measurements but dynamically reconstructing full spectral information datasets.

Assembly of optoelectronics for efficient chip-to-waveguide coupling

“…When aligned, the PMMA piece is glued to the chip package using an UV curable adhesive. The coupling loss between an embedded VCSEL and a multimode optical fiber is 2,8 dB [6]. This approach results in the highest level of integration.…”

Rapid and broad wavelength sweeping of standard telecommunication distributed feedback laser diode

“…Using the presented method and an off-the-shelf telecommunication distributed feedback laser diode, we demonstrate wavelength sweeps in excess of 10 nm that were completed in about 200 ns, while generating average optical power in excess of 50 mW. In spite of high-amplitude current-drive pulses, 6000 h continuous operation of the diode within such an operational regime did not show any significant degradation of the diode ' Change of emitted optical wavelength versus time, e.g., wavelength-sweep, is required within many photonic measurements and similar systems [1,2]. Furthermore, rapid wavelength sweep rates are often needed in dynamic measurements [3] or during time division multiplexing of sensors' arrays [4].…”

Evaluation of a 1540nm VCSEL for fibre Bragg gratings interrogation in dynamic measurement applications

“…Typical range of operation is from 0°C to 70°C. Their use is being extended to new applications that are dramatically improved in terms of the overall cost, energy consumption of the system and compactness [6].…”