METHODS FOR DETERMINING OPTICAL POWER, FOR POWER NORMALIZING LASER MEASUREMENTS, AND FOR STABILIZING POWER OF LASERS VIA COMPLIANCE VOLTAGE SENSING

摘要

A method is disclosed for power normalization of spectroscopic signatures obtained from laser based chemical sensors that employs the compliance voltage across a quantum cascade laser device within an external cavity laser. The method obviates the need for a dedicated optical detector used specifically for power normalization purposes. A method is also disclosed that employs the compliance voltage developed across the laser device within an external cavity semiconductor laser to power-stabilize the laser mode of the semiconductor laser by adjusting drive current to the laser such that the output optical power from the external cavity semiconductor laser remains constant.

主权项

1. A method of stabilizing an optical power of an external cavity laser, comprising the steps of:
driving a laser device disposed within the external cavity laser with a current through the laser device from a current controller; measuring the compliance voltage across the laser device; applying a mathematical function to the compliance voltage to produce an optical power signal proportional to an optical power of the external cavity laser; feeding the optical power signal back to the current controller to change the current delivered to the laser device; and adjusting feedback parameters to stabilize the optical power of the external cavity laser.