Bandwidth reconfigurable microwave photonic filter based on stimulated Brillouin scattering

• Filter bandwidth narrowing and broadening based on SBS effect are proposed.
• Near 60% bandwidth reduction is obtained arising from gain spectrum narrowing.
• Filter bandwidth broadening from a few tens of MHz to several GHz is obtained.

A bandwidth reconfigurable microwave photonic filter is proposed and numerically analyzed employing Brillouin gain spectrum narrowing and broadening. The stimulated Brillouin scattering (SBS) process is used to convert the phase modulation to intensity modulation to generate filter passband. Due to the fact that the passband is formed by mapping the Brillouin gain spectrum, bandwidth reconfiguration can be implemented by changing Brillouin gain linewidth. In this paper, both bandwidth reduction and increase are included in a single system and the details of gain spectrum narrowing and broadening are demonstrated. Theoretically, nearly 60% bandwidth reduction and hundreds times of bandwidth increase are achieved as compared to the case without gain spectrum process.