Fig. 4: Microwave photonic channelization.
From: Electrically interfaced Brillouin-active waveguide for microwave photonic measurements
a Operating principle of a multi-segment electrically interfaced Brillouin-active waveguide for microwave photonic channelization. Intensity-modulated light (ii) carrying a wideband RF signal (i) is injected into the system, which excites localized phonons at each electro-optomechanical region. Each phonon generates a microwave signal output with a designed center frequency and targeted bandwidth (iii–v). Despite undergoing several phase modulations, the output optical field preserves the intensity envelope, ensuring that the RF information encoded in the optical signal remains unaltered. b The cross-section of the Brillouin-active waveguide, illustrating the membrane width W and the number of IDT teeth N. c Tunability of the microwave filter center frequency using the membrane width (W) of W1 = 14.70 μm, W2 = 15.43 μm, and W3 = 16.15 μm. d Tunability of the microwave filter bandwidth using the number of IDT teeth.
