| 摘要 |
PROBLEM TO BE SOLVED: To calibrate the reference of the optical axis of an optical axis deviation angle measuring instrument, using a semiconductor laser which has an unknown optical axis deviation angle. SOLUTION: The temporary reference S of the optical axis of an optical axis deviation angle measuring instrument is set, and based on the set temporary reference S of the optial axis, the first optical axis deviation angle Δθ1 of a semiconductor laser 20 for calibration is measured with a photodiode 32, and the second optical axis deviation angle Δθ2 is measured again with the photodiode 32, in a state that the semiconductor laser 20 is rotated 180 deg., and the true reference S0 of the optical axis of an optical axis deviation angle measuring instrument is obtained from the average value of that measured optical axis deviation angle measuring instrument. At this time, the angle Δθm formed between the true reference S0 of the optical axis of the optical axis deviation angle measuring instrument and the temporary refernece S of the optical axis is given by an equation Δθm=(Δθ1 +Δθ2 )/2. On the stage of obtaining the average value, the true optical axis deviation angel Δθ of the semiconductor laser 20 is negated, so there is no necessity of the true optical axis deviation angle Δθ being known. |
