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.