Fig. 1. Schematic diagram for programmable, multifunctional integrated photonic chip

Fig. 2. Device characteristics of three typical structures. (a)(b) Schematic diagram and transmission spectrum of All-pass micro-ring resonator; (c)(d) schematic diagram and transmission spectra of Add-drop micro-ring resonator; (e)(f) schematic diagram and transmission spectra of MZI structure

Fig. 3. Schematic and operation modes of a reconfigurable a silicon micro-ring switch^[27,31]. (a) Device diagram; (b) scanning electron microscope figure; (c) transmission spectra of a switch in block/pass mode; (d) transmission spectra in pass/block mode; (e) transmission spectra inpass/pass mode; (f) method of calculating product based on microring cascade

Fig. 4. Programmable and multifunctional optical logic computing chip based on multi-wavelength configuration. (a) 2×2 chip structure diagram^［22］; (b) picture of packaged 2×2 chip^［22］; (c) 2×2 chip logic operation result^[22]; (d) 1×4 chip structure diagram^［25］; (e) 1×4 chip microscope image^［25］; (f) 1×4 chip logic operation result^[25]

Fig. 5. Programmable and multifunctional optical logic computing chip based on single-wavelength configuration. (a) Based on 1×1 multi-input microring optical switch chip structure diagram^[29]; (b) 1×1 chip spectrogram^[29]; (c) true table^[29]; (d) structure diagram of programmable computing chip based on 3×4 optical switch^［32］; (e) 3×4 optical switch chip microscope image^［32］; (f) calculated results of a 3×4 optical switch chip^[32]

Fig. 6. Resonator based forward optical signal processing chips. (a) Structure diagram of a programmable, multifunctional optical signal processing chip based on 8×8 micro-disk^［58］; (b) programmable optical beamforming function^［58］; (c) programmable optical pulse shaper function^[58]; (d) structure diagram of a programmable optical signal processing chip based on 6 microring resonators^［20］; (e) programmable delay function^[20]

Fig. 7. MZI based forward optical signal processing chips. (a) Programmable 8×8 silicon optical signal processing chip^［63］; (b) MIMO descrambler function^[63]; (c) programmable optical signal processing chip based on cascaded MZI couplers and PDs^［61］; (d) arbitrary waveform generation function^[61]

Fig. 8. Recirculating optical signal processing chips based on square or triangular waveguide meshes. (a) Silicon nitride optical information processing chip based on square waveguide meshes^［34］; (b) band-stop filter^［34］; (c) band-pass filter^[34]; (d) silicon nitride optical information processing chip based on triangular waveguide meshes^［23］; (e) design of a silicon nitride optical information processing chip layout^［23］; (f) reflection spectra of single ring resonator^［23］; (g) reflection spectrum of double ring resonator^[23]

Fig. 9. Recirculating optical signal processing chips based on hexagonal waveguide meshes. (a) Layout of a silicon programmable optical signal processing chip based on the 7-cell hexagonal waveguide meshes^［45］; (b) programmable structure^［45］; (c) optical filter^[45]; (d) layout of a silicon programmable optical signal processing chip based on the 72-cell hexagonal waveguide meshes^［55］; (e) chip image after packaging^［55］; (f) optical transfer function^［55］; (g) microwave photon filtering function^[55]