Calibrating lasers for optical recording using a maximal readback signal amplitude as a criterion

摘要

A magnetooptic recorder uses a magnetooptic disk for any predetermined number of radially inward tracks which are designated as calibration tracks. One of the calibration tracks is selected as a laser calibration track. The selected track is high powered erased and a test pattern is written on the track. A test pattern is repeated at diverse levels of laser recording power. A test pattern preferably includes or is limited to the highest frequency to be recorded in the ensuing data recordings. The recorded test pattern is read back with the readback signal amplitude being envelope indicated and detected. A table of signal envelope values is created in a digital computer. The values then are fit to a curve using second order polynomial curve fitting techniques. The maximal readback signal amplitude is then selected from the curve corresponding to laser write power used to obtain that maximum signal amplitude and is then selected as a criteria for indicating the laser write power as well as the erase write power.