Patent ID: 7436864

Claim:
A method of calibrating a multi-section tuneable laser to a specific frequency, the method comprising the steps of: a) measuring output values from the laser as a function of coarse tuning currents of the laser, b) forming a first discrete matrix from said output values from the laser, the first discrete matrix being defined by an optical characteristic of the output of the laser at specific determining tuning currents, c) processing the first discrete matrix so as to determine stable operating points within the first discrete matrix, the stable operating points defining specific frequencies where the laser may be operated, and d) determining whether the determined stable operating points represent the optimum stable operating points by the step of: i) dilating the set of points that are defined as contributing to an edge in the edge matrix by one pixel so as to widen edges of the matrix, thereby forcing the edges to join where gaps exist, ii) determining whether more than one operating point is in each dilated bounded region, iii) if more than one operating point is found in the region above it measuring the frequency of the laser at these points, and iv) determining whether the difference between the measured frequency of the laser and the mode jump spacing is within a predetermined value and, if it is within the value averaging the plurality of operating points to provide a single operating point within that bounded region or, if it is not within that predetermined value, allowing for a plurality of points within that region.