公开(公告)号：US20070160095A1

公开(公告)日：2007-07-12

申请号：US11439424

申请日：2006-05-24

申请人： Kentaro Kitagawa ,  Hiroto Ishibashi

发明人： Kentaro Kitagawa ,  Hiroto Ishibashi

IPC分类号： H01S3/13

CPC分类号： H01S5/0683 ,  H01S5/0617 ,  H01S5/06804

摘要： This invention provides an automatic power control (APC) circuit for keeping an extinction ratio constant even when the efficiency of a laser diode (LD) deteriorates. The APC circuit according to this invention stores first control data for deciding the relationship between a bias current Ib and a modulation current Im so that the extinction ratio under a certain target power is a predetermined value. A central processing unit (CPU) decides the bias current Ib and modulation current Im on the basis of a current optical output power and the first control data and supplies them to an LD driver. The APC circuit also stores second control data for deciding the correction value for the optical output power corresponding to the temperature of the LD. The CPU acquires the current temperature before deciding the bias current Ib, decides a correction value corresponding to the current temperature according to the second control data, and corrects the target power. Thereafter, the CPU computes the bias current Ib on the basis of the corrected target power.

摘要翻译： 本发明提供一种自动功率控制（APC）电路，用于在激光二极管（LD）的效率降低时保持消光比恒定。 根据本发明的APC电路存储用于确定偏置电流Ib和调制电流Im之间的关系的第一控制数据，使得在某一目标功率下的消光比是预定值。 中央处理单元（CPU）基于当前光输出功率和第一控制数据来确定偏置电流Ib和调制电流Im，并将其提供给LD驱动器。 APC电路还存储用于决定与LD的温度对应的光输出功率的校正值的第二控制数据。 在决定偏置电流Ib之前，CPU获取当前温度，根据第二控制数据确定与当前温度对应的校正值，并校正目标功率。 此后，CPU基于校正的目标功率来计算偏置电流Ib。