10Gb/s direct modulation of widely tunable V-cavity-laser with chirp managed laser technology

Abstract

We report direct modulation results in a simple and compact widely tunable V-cavity laser. Chirp managed laser technology has been successfully applied to the V-cavity laser with an optical spectrum reshaping filter. The tunable V-cavity-laser employs a half-wave coupler to obtain single-mode operation with high side-mode suppression ratio and the Vernier effect to extend its tuning range. It does not require any grating structure and regrowth steps. In this experiment, we achieved single-electrode controlled wavelength tuning of about 18 channels at 100GHz spacing with a fixed temperature, and 32 channels using 2 temperature settings. Well-open eye diagrams with extinction ratio above 4.3dB in all channels are observed when the laser is directly modulated at 2.5Gb/s. Although the measured small-signal frequency response is only about 5.7GHz, more than 6.7dB extinction ratio under 10Gb/s modulation rate is achieved by using the chirp managed laser technology with an optical spectrum reshaping filter placed after the output of the laser to convert the frequency chirp accompanying the direct modulation to amplitude modulation. The advantages of compactness, fabrication simplicity, easy wavelength control algorithm, and simple direct modulation offer great potential for the chirped managed V-cavity laser to be used in low-cost WDM links.