Simple method for measuring frequency chirps with a Fabry-Perot interferometer

A simple method for measuring the frequency-chirped response of lasers is presented. This method relates the deviation from the Lorentzian line shape of the transmission of a Fabry-Perot interferometer to the frequency chirp of the laser and allows a direct measurement of the frequency chirp. Two chirps produced by an external-cavity laser diode with an intracavity electro-optic crystal were measured. The first measurement was of a linear chirp of 800 MHz occurring in a time of 12.3 micros, and the second measurement was of eight repeated 800-MHz linear chirps each occurring in 337 micros. Agreement between the measured and the expected frequency-chirped response of the laser is shown.