Dense Wavelength Division Multiplexing Based on Soliton Crystal Microcomb Interweaving

Photonic signal processing technology based on on-chip Kerr microcombs enables various signal processing functions such as programmable filters, channelization, convolutional intelligent acceleration, integration/differentiation calculations, and wide-instantaneous-bandwidth beamforming. The core principle involves the temporal-wavelength interweaving effect of equidistant microcomb wavelength channels after transmission through dispersive media, which allows for specific functional processing of signals. However, existing on-chip microring resonators have limitations in the number of effective wavelength channels and spectral resource utilization, typically generating fewer than 100 channels concentrated around the pump wavelength. To overcome these limitations, this paper proposes a soliton crystal microcomb architecture with wide spectral coverage and high parallel wavelength channels based on dual-comb interweaving. The method uses two isomorphic and homogeneous integrated on-chip Kerr microring chips and employs thermal tuning for precise control of the center wavelength of soliton crystal microcombs. This approach significantly increases the number of available parallel wavelength channels while ensuring equal wavelength spacing and effective dense overlap of wavelengths. The results demonstrated the successful generation of an on-chip Kerr optical frequency comb system with up to 200 wavelength channels. Due to manufacturing tolerances, the repetition rates of the soliton crystal microcombs generated by two Kerr microcomb chips inevitably differ, which affects the repetition rate of the combined microcomb. Through the on-chip Kerr microcomb system, we demonstrate an effective wavelength division multiplexing scheme for photonic intelligent signal processing that effectively addresses the aforementioned issue. This work paves the way for more efficient and versatile photonic signal processing applications. © 2026 SPIE.