Wideband high-power external cavity wavelength tunable laser

Abstract

Wideband wavelength tunable lasers are now beginning to play important roles in dense wavelength-division multiplexing (DWDM) optical transmission systems, because these lasers can reduce the required number of inventory lasers and inventory costs. They are also key components in the evolution towards future photonic network systems, particularly in reconfigurable optical add/drop multiplexing (ROADM) systems and optical cross-connect (OXC) systems. However, before the tunable laser can be a viable alternative for the conventional fixed wavelength laser (e.g. DFB laser) it should have the same characteristics over its entire tuning range. Additionally, the device should only be marginally more expensive than its fixed counterpart. This paper reviews our recent activities on the development of high performance full-band wavelength tunable lasers. Our approach utilizes an external cavity configuration, which makes use of a liquid crystal (LC) tunable mirror. We demonstrate high performance of an external cavity wavelength tunable laser (ECTL) with an intracavity etalon. This ECTL module shows a tuning range of 45 nm, fiber-coupled output power of higher than 14 dBm with SMSR of better than 59 dB, wavelength accuracy of +/-0.6 GHz, relative intensity noise (RIN) of better than - 150 dB/Hz, and linewidth of narrower than 1 MHz.