  Optical pulse shaping stands as a formidable technique in ultrafast optics,
radio-frequency photonics, and quantum communications. While existing systems
rely on bulk optics or integrated platforms with planar waveguide sections for
spatial dispersion, they face limitations in achieving finer (few- or sub-GHz)
spectrum control. These methods either demand considerable space or suffer from
pronounced phase errors and optical losses when assembled to achieve fine
resolution. Addressing these challenges, we present a foundry-fabricated
six-channel silicon photonic shaper using microresonator filter banks with
inline phase control and high spectral resolution. Leveraging existing
comb-based spectroscopic techniques, we devise a novel system to mitigate
thermal crosstalk and enable the versatile use of our on-chip shaper. Our
results demonstrate the shaper's ability to phase-compensate six comb lines at
tunable channel spacings of 3, 4, and 5 GHz. Specifically, at a 3 GHz channel
spacing, we showcase the generation of arbitrary waveforms in the time domain.
This scalable design and control scheme holds promise in meeting future demands
for high-precision spectral shaping capabilities.
