发明名称 DETECTION CIRCUIT FOR DETERIORATION IN SEMICONDUCTOR LASER
摘要 PURPOSE:To prevent the LD deterioration signal from falsely transmitted due to any input signal disconnection by a method wherein a mark rate detection circuit is made to detect the mark rate of input signals. CONSTITUTION:A current voltage converter 51 converts the output photoelectric current of a photodetector element 22 detecting the output from a semiconductor laser (LD) 21 into voltage signals. A mark rate detector 52 detects the mark rate of input signals. An amplifier 53 amplifies the output signals from the current voltage converter 51 and the output signals from the mark rate detector 52. A bias current controller 54 controls the bias current from a semiconductor laser 21. A comparator 55 compares the output from the amplifier 53 with set up value to detect any deterioration in the semiconductor laser 21. Through these procedures, only the deterioration in the LD module can be accurately detected.
申请公布号 JPH02296381(A) 申请公布日期 1990.12.06
申请号 JP19890116966 申请日期 1989.05.10
申请人 MATSUSHITA ELECTRIC IND CO LTD 发明人 SANADA TAKESHI
分类号 H04B10/07;H01S5/042;H04B10/079;H04B10/2507 主分类号 H04B10/07
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