Laser diodes are very fast devices that react rapidly to changing voltage and current. While this is a benefit in applications such as signalling, it is also a potential liability. Laser diodes are vulnerable to electrostatic discharge (ESD) events and power surges. Blu-ray and low-power red laser diodes are particularly susceptible to voltage spikes, since any increase in applied voltage beyond normal operating parameters will cause both optical and electrical overstress.

Anecdotal evidence suggests that many laser diodes fail long before their life expectancy. One reason is ESD and power surges generated during power on/off cycles. Voltage spikes are often produced at these times, and their cumulative effect on laser diodes is detrimental.

To solve the ESD problem, in 2008 Pangolin Laser Systems developed an electrical component called LASORB. The word LASORB is a combination of the words “LASER” and “ESD ABSORBER”. The LASORB component is easy for engineers to implement because it is small and can simply be connected directly to the pins of the laser diode.

LASORB’s primary means of protection is a slew-rate detector that monitors the voltage across the pins of the laser diode. If there is a fast change-of-voltage condition detected, this triggers LASORB to aggressively conduct the voltage (and thus current) away from the laser diode. The conduction is initiated very rapidly – in some cases less than one nanosecond. The conduction can last from several microseconds, to tens of microseconds.

More information can be found on Lasorb.com.