Stabilisation of central wavelength of erbium‐doped fibre source as part of high‐accuracy fibre optic gyroscopes

Abstract

The stability of the central wavelength of the erbium-doped fibre source (EDFS) is one of the most important parameters to ensure the accurate operation of navigation systems based on high-accuracy fibre optic gyroscopes (FOGs). Herein, the method of stabilisation of the EDFS as a part of the FOG is presented. The main advantage of this method is the possibility of quick and simple matching of temperature-compensating spectral filters by changing the pump ratio without modifying the optic scheme. The EDFS optic scheme is based on the double-pass bidirectional pumping configuration. This makes it possible to obtain the world-class stability of the central wavelength of the EDFS as a component of different devices with the spectral selectivity and set the constant value of the optic power of the output light (OL). Also, this is the first study into the dependence of the temperature coefficient of the central wavelength on the pump ratio. The proposed method allows compensating the spectral characteristics of the FOG, achieving the OL central wavelength stability around 0.7 ppm/°C and the FOG scale factor stability around 0.73 ppm/°C.