Wavelength channel accuracy of an external cavity wavelength tunable laser with intracavity wavelength reference etalon

A theoretical and experimental study of the wavelength channel accuracy of an external cavity wavelength tunable laser (ECTL) with a wavelength reference etalon inside the laser cavity is presented. A feedback control scheme for wavelength locking is proposed based on monitoring of the forward output power. The cavity parameters with an impact on the channel accuracy, using the proposed scheme, are indicated, and guidelines toward optimization of the etalon are proposed. Experimental demonstration of a channel accuracy of less than 0.6 GHz for a full C-band ECTL with a channel spacing of 50 GHz confirms the high potential of this laser configuration