Wavelength referencing by monitoring a voltage across a laser diode

摘要

A lasing wavelength of a laser diode is determined by applying a forward current to the p-n junction of the laser diode and measuring a voltage across the p-n junction. The lasing wavelength can be determined by performing a simple wavelength calibration of the laser diode. This allows one to stabilize the lasing wavelength, and also to use the laser diode as a reference wavelength source.

主权项

1. An optical system comprising:
a controller for a laser diode, the controller comprising: a current source for providing a driving current to the laser diode; a voltmeter for measuring a voltage across the laser diode; and a control circuit coupled to the current source and the voltmeter, the control circuit structured and arranged to: cause the current source to supply a first driving current to the laser diode above a lasing threshold of the laser diode to emit light at a first wavelength; cause the current source to supply a second driving current to the laser diode; cause the voltmeter to measure a reference value of a forward-bias voltage across the laser diode when the second driving current is supplied; and compute the first wavelength based on the reference value of the forward-bias voltage.