ABSTRACT
This chapter introduces an overview on micro-electro-mechanical-system (MEMS)-based swept laser sources. It begins with presenting the different wavelength-tuning sources, the principle of operation of swept sources, and the most common wavelength-scanning techniques. In addition, an overview is provided on the MEMS technology; the silicon-on-insulator (SOI) and the deep reactive ion etching (DRIE) technologies, as well as the comb-drive actuators. Then, it goes deep into one of the most common configurations of the swept sources, the fibre-ring laser source with an intracavity tunable filter. First, the tunable filter is introduced, which is a MEMS-based Fabry–Perot (FP) etalon with deeply etched 80 µm height silicon/air Bragg mirrors, allowing a tuning range of up to 125 nm. The static behaviour of the swept source system is then studied, where a wavelength-tuning range of up to 100 nm and a 3-dB spectral linewidth of 0.13 nm are reported. Finally, its dynamic behaviour is studied showing a hysteresis in the performance during sweeping at the different directions. The performance dependence on the pumping current, the scanning speed, and the fibre-loop length is studied as well.
