| 摘要 |
A method or algorithm to control a driving current supplied to a semiconductor laser diode (LD) is disclosed. the method first prepares the look-up-table (LUT) that stores a set of parameters, α and β, for evaluating the modulation current Im by the equation of Im=α×Ib+β, where Ib is determined by the auto-power-control (APC) loop. In a practical operation of the LD, the APC loop determines Ib, while, Im is calculated according to the equation above by reading above two parameters corresponding to the current temperature of the LD from the LUT. |
| 主权项 |
1. A method to drive a semiconductor laser diode (LD) by supplying a bias current determined by an auto-power control (APC) loop and a modulation current Im calculated from the bias current based on a linear dependence of Im=α×Ib+β, the method comprising steps of:
preparing a look-up-table (LUT) by procedures including, evaluating a plurality of sets of two parameters, (α, β)i (i=1 to n), at respective temperatures Ti (i=1 to n), evaluating a first linear dependence of one of parameters, αi (i=1 to n), against temperatures to determine a slope and a y-intercept, aα and bα, of the first linear dependence, respectively and a second linear dependence of another of parameters, βi (i=1 to n), against temperatures to determine a slope and a y-intercept, aβ and bβ, of the second linear dependence, respectively, storing two slopes, aα and aβ, and other two y-intercepts, bα and bβ, in the LUT; sensing a current temperature T of the LD; calculating a set of parameters (α, β)T by referring to two slopes, aα and aβ and two y-intercepts, bα and bβ in the LUT, according to equations of:
αT=aα×T+bα, andβT=aβ×T+bβ. |
