|
Recent advances in integration technologies enable constructing novel, highly complex and miniaturized photonic systems for a large variety of applications. A constantly increasing interest can be observed in implementing application specific photonic integrated circuits (ASPICs) in a new generation of optical sensing systems.
The InP platform allows to realize complete interrogators of sensing systems, comprising the light sources and photodetectors. An InP PIC can also be used as a sensing element itself. In this work we discuss the sensing systems addressing two different application fields, which can benefit from the recent developments of InP platforms - optical gyroscopes and interrogators of fiber Bragg gratings.
The principle of work of optical gyroscope is based on the Sagnac effect. Two typical configurations can be identified – interferometric fiber-optic gyroscope (IFOG) and ring laser gyroscope (RLG). An integrated interrogator unit of an IFOG system presented here was realized using a DBR laser, passive couplers and PIN photodiodes. Characterization results have proven the possibility of detection of the Sagnac signal for the length of the fiber loop of 1 km. We also discuss monolithic single-frequency lasers, which were realized in the framework of the development of an integrated optical gyro.
Also, the integrated interrogators of fiber Bragg gratings are presented and discussed. The investigated solutions are based on the interrogation scheme in which a broadband signal is coupled to a network of FBGs, and the reflected signals are analyzed using a spectrometer based on an arrayed waveguide grating. Several realized circuits are discussed with respect to their design, characterization results and potential for application in sensing systems.
Studies were funded by FOTECH-1 project granted by Warsaw University of Technology under the program Excellence Initiative: Research University (ID-UB). This work was partially supported by National Centre for Research and Development (PBS3/B9/41/2015).
|
