Electrostatic discharge damage to pump lasers while operating

GaInAsP buried heterostructure pump lasers emitting at approximately 1480nm have been subjected to simulated electrostatic discharge pulses, with one added feature over usual practice in that the lasers were run at close to maximum output while the pulses were applied. Using pulses in the forward bias direction, no perceptible damage occurred at up to 50 kV from a standard human body model of 100 pF discharging through 1500 Omega and the device under test. ESD pulses in the reverse direction caused damage at 5 to 12 kV, and the damage threshold was increased by about 600 V when the lasers were running during the test. Analysis of data, and physical arguments reveal the likely nature of damage and its causes, and the applicability of this theory to other device structures and wavelengths is discussed.