Self-healing coatings incorporate microcapsules of about 60-150 microns diameter that contain film formers and dust suppression compounds suitable for controlling spalling of lead dust, for example. One or more fabrication processes associated with fiber preparation may be performed on an optical fiber without requiring active user input. A current indicator is used to indicate a currently valid dimension. Based on the one or more symbol indices a set of possible start symbol indices is established. Horizontal connections are used to interconnect PIN photodiodes in the rows in accordance with a second pattern that interconnects two or more adjacent rows. The peak of the first impurity concentration is smaller than the peak of the second impurity concentration.