Time-Resolving Wavelength Chirp with Fabry-Perot Etalons and Gratings: A Theoretical Approach

Basic dynamic properties of Fabry-Perot etalons and gratings are investigated for a square-wave shaped input pulse with a linearly changing wavelength. It is shown that for the chirp rates present in DFB laser pulses a simultaneous good resolution in the wavelength and time domain is attainable with an etalon due to its small FWHM time-bandwidth product of 0.11. This is not possible with the grating which has a time-bandwidth product of 0.89. A simulated measurement of time resolving the dynamic chirp of a DFB laser pulse is presented and compared to the actual incident wavelength chirp. © 1991 IEEE