Tuning optical spectrum between Fano and Lorentzian line shapes with phase control

Controlling the spectrum of light with a phase has received intensive interest of researchers recently. Here, we study the phase control of the spectral line shape of the output from an optical March-Zehnder interferometer (MZI) with one arm involving a high quality Fabry-Perot cavity. Due to the interaction of the narrow-band light transmitted through the cavity with the broadband light, the spectrum can be tuned from Lorentzian to Fano-like profile with a phase shifter in MZI.