Figure 6: Layout of a fully integrated microwave photonics signal processor.
From: Integrable microwave filter based on a photonic crystal delay line
The weighting coefficients ak of the impulse response of the processing unit are programmed through the relative power levels of the TLSs, whereas the selected wavelengths set the taps group delays τk, and hence the filter FSR. DL, photonic crystal delay line; IM, intensity modulator; PD, photodiode; Semiconductor optical amplifiers C, 4:1 optical combiner; TLS, tunable laser source.
