Apparatus and method for calibrating the drive current circuit of a semiconductor laser diode subject to reflected optical feedback from a target surface such an an optical recording disk. The method makes use of two power output vs. drive current characteristic curves for the laser, one curve for in...http://www.google.de/patents/US5216659?utm_source=gb-gplus-sharePatent US5216659 - Laser power calibration by measuring laser drive current at out of focus and in focus conditions
