PREHEATING LASER DIODES WITH REVERSE BIAS FOR HAMR DISK DRIVES

A data storage device may include one or more disks, an actuator arm assembly comprising one or more disk heads, at least one laser diode positioned inside a corresponding laser diode cavity, a preamplifier, and one or more processing devices. The one or more processing devices are configured to: generate a reverse bias; apply, using the preamplifier, the reverse bias to the at least one laser diode to preheat a corresponding laser diode cavity to a target temperature prior to a write operation; control transition of the preamplifier from applying the reverse bias to applying a forward bias to the at least one laser diode; and activate the at least one laser diode to begin the write operation.