Visible-Laser Driver Has Digitally Controlled Power Modulation

Abstract: The circuit in the figure below includes a 10-bit digital-to-analog converter (DAC) with 3-wire serial input that operates and maintains a visible-light laser diode at constant average optical output power. A separate digital input line (MOD) enables a comparator with open-drain output (IC4) to implement digital communications by pulsing the laser-diode through Q1.
Maxim > App Notes > A/D and D/A CONVERSION/SAMPLING CIRCUITS
AMPLIFIER AND COMPARATOR CIRCUITS FIBER-OPTIC CIRCUITS

Keywords: modulated laser, diode driver, visible-light laser, optical, photodiode, photo diode, peak optical Jul 01, 2001
power, visible laser driver

APPLICATION NOTE 1811
Visible-Laser Driver Has Digitally Controlled Power Modulation

Abstract: The circuit in the figure below includes a 10-bit digital-to-analog converter (DAC) with 3-wire serial
input that operates and maintains a visible-light laser diode at constant average optical output power. A
separate digital input line (MOD) enables a comparator with open-drain output (IC4) to implement digital
communications by pulsing the laser-diode through Q1.


Many laser diodes include a photodiode that generates a current