| 摘要 |
PURPOSE:To make the plural shutter mechanisms and control units unnecessary and to reduce the cost of apparatus, by executing a current seanning only one side peak width of minute absorption characteristics by driving current and always correcting its peak value at a specific position of the current scanning extent by a microcomputer. CONSTITUTION:An electric signal photoconverted by a detector 6 is inputted in lockin amplifiers LA1, LA2 and a value P of absorption characteristics and value P' of differential absorption characteristics are outputted. These values P and P' are inputted in a microcomputer 7 through A/D converters 15a, 15b and are stored in a storage device 9 conducting a division operation. On the one hand, the laser 5 is scanned by driving current in a width of current value showing P'/P a peak and the current corresponding to the peak position of divided value of P'/P is fetched as a control signal. Then, the signal is inputted in a power source 8 from an adder 19 through a converter 18 and the maximum and minimum values of scanned current are corrected so as to be the center of the current extent to be scanned. |
