METHOD OF PULSE-MODE DRIVING OF A SEMI-CONDUCTOR LASER, DRIVING DEVICE FOR A SEMI-CONDUCTOR LASER AND LASER-WRITING APPARATUS PROVIDED WITH SUCH A DRIVING DEVICE

摘要

Method of pulse-mode driving of a semi-conductor laser, driving device for a semi-conductor laser and laser-writing apparatus provided with such a driving device. A semi-conductor laser (60) is driven by first driving the laser in the LED region with a pedestal current pulse from a first current source (41) and by superposing thereon an information current pulse from a second current source (51) after current stabilization. Due to this two-stage drive switching transients can be reduced so that shorter pulses are possible and unnecessary power dissipation between the information pulses is avoided which contributes to the lifetime of the semi-conductor laser. Figure 5.