A current output of a drive signal, modulated between two current
settings, is applied to a laser diode, e.g. VCSEL. The settings are
selected such that laser diode's power output meets the average power and
peak power limits of the eye safety standards. The drive signal having a
duty cycle toggling between the two settings. The duty cycle is selected
such that the average and peak power limits are met for the given upper
current setting. The drive circuit may include an analog modulator or
digital analog converter (DAC) for maintaining the lower and upper
current settings. When the drive circuit is implemented as an integrated
circuit, the DAC may be incorporated into the IC. The sensitivity of the
DAC is selected to maintain the desired lower and upper current settings.