Feedback Coupling Module of Optical Transceiver Using Projection Core Fiber

Abstract

We propose a unique type optical transceiver with a lens position feedback control system to preserve a high optical coupling efficiency between a laser diode and a single-mode fiber (SMF). In this method, accurate alignment or welding is eliminated in the assembly of optical components. This system is also free from a long-term optical power change caused by optical component displacement with environmental variation in temperature and oscillation. In this study, we investigated an optical coupling system, where the position of an optical axis is tuned by active feedback control detecting the optical diffractive pattern from a projecting core fiber (PrCF). By this method, the optical transceiver enabled a lens position control of less than 0.3 µm in a noise environment of 100 Hz–0.25G (G-forces), and was able to maintain optical transmission.