• Photonics Research
  • Vol. 10, Issue 6, 1509 (2022)
Younghyun Kim1、2、*, Didit Yudistira1, Bernardette Kunert1, Marina Baryshnikova1, Reynald Alcotte1, Cenk Ibrahim Ozdemir1, Sanghyeon Kim1、3, Sebastien Lardenois1, Peter Verheyen1, Joris Van Campenhout1, and Marianna Pantouvaki1
Author Affiliations
  • 1IMEC, Heverlee B-3001, Belgium
  • 2Current address: Department of Photonics and Nanoelectronics, BK21 FOUR ERICA-ACE Center, Hanyang University, Ansan 15588, Republic of Korea
  • 3Current address: School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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    DOI: 10.1364/PRJ.451821 Cite this Article Set citation alerts
    Younghyun Kim, Didit Yudistira, Bernardette Kunert, Marina Baryshnikova, Reynald Alcotte, Cenk Ibrahim Ozdemir, Sanghyeon Kim, Sebastien Lardenois, Peter Verheyen, Joris Van Campenhout, Marianna Pantouvaki. Monolithic GaAs/Si V-groove depletion-type optical phase shifters integrated in a 300 mm Si photonics platform[J]. Photonics Research, 2022, 10(6): 1509 Copy Citation Text show less
    (a) Schematic of a Mach–Zehnder modulator with the III–V/Si optical phase shifters in both arms. (b) Cross-section of the GaAs/Si optical phase shifter.
    Fig. 1. (a) Schematic of a Mach–Zehnder modulator with the III–V/Si optical phase shifters in both arms. (b) Cross-section of the GaAs/Si optical phase shifter.
    Integration flow of the GaAs/Si optical phase shifter. (a) Si-on-insulator, (b) waveguide formation, (c) L-shape pn junction formation, (d) Si V-groove formation, (e) epitaxial GaAs growth on Si V-groove, (f) planarization, and (g) SiO2 passivation and electrode formation.
    Fig. 2. Integration flow of the GaAs/Si optical phase shifter. (a) Si-on-insulator, (b) waveguide formation, (c) L-shape pn junction formation, (d) Si V-groove formation, (e) epitaxial GaAs growth on Si V-groove, (f) planarization, and (g) SiO2 passivation and electrode formation.
    (a) Cross-section of the optical phase shifter and (b) the magnified dashed yellow rectangle for GaAs/Si V-groove.
    Fig. 3. (a) Cross-section of the optical phase shifter and (b) the magnified dashed yellow rectangle for GaAs/Si V-groove.
    EDX images of (a) Si, (b) Ga, and (c) As.
    Fig. 4. EDX images of (a) Si, (b) Ga, and (c) As.
    Optical microscopic top-view image of the fabricated GaAs/Si V-groove lumped MZ modulators of 500-, 1000-, and 1500-μm-long optical phase shifters at both arms.
    Fig. 5. Optical microscopic top-view image of the fabricated GaAs/Si V-groove lumped MZ modulators of 500-, 1000-, and 1500-μm-long optical phase shifters at both arms.
    Electrical characteristics of the pn junction in the GaAs/Si and Si optical phase shifters: (a) current-voltage and (b) capacitance-voltage.
    Fig. 6. Electrical characteristics of the pn junction in the GaAs/Si and Si optical phase shifters: (a) current-voltage and (b) capacitance-voltage.
    Bias-dependent measured spectra of the lumped MZ modulators with the 500-μm-phase shifter length: (a) the Si reference and (b) the GaAs/Si.
    Fig. 7. Bias-dependent measured spectra of the lumped MZ modulators with the 500-μm-phase shifter length: (a) the Si reference and (b) the GaAs/Si.
    (a) Extracted phase shift and (b) VπL as a function of the bias voltage for the GaAs/Si and the Si reference optical phase shifters.
    Fig. 8. (a) Extracted phase shift and (b) VπL as a function of the bias voltage for the GaAs/Si and the Si reference optical phase shifters.
    Phase shifter length-dependent measured spectra of the lumped MZ modulators with 500-, 1000-, and 1500-μm phase shifter lengths: (a) the Si reference and (b) the GaAs/Si.
    Fig. 9. Phase shifter length-dependent measured spectra of the lumped MZ modulators with 500-, 1000-, and 1500-μm phase shifter lengths: (a) the Si reference and (b) the GaAs/Si.
    Normalized insertion as a function of the phase shifter length for extracting the propagation loss of the GaAs/Si and the Si reference phase shifters.
    Fig. 10. Normalized insertion as a function of the phase shifter length for extracting the propagation loss of the GaAs/Si and the Si reference phase shifters.
    (a) Test site of the spiral waveguides including the GaAs/Si waveguide, the Si waveguide, and the waveguide transition. (b) The GaAs/Si waveguide region, red-colored rectangle. (c) The waveguide transition region from the Si to the GaAs/Si waveguide, blue-colored rectangle. (d) The measured transmission of the REF waveguide, Spiral 01, and Spiral 02.
    Fig. 11. (a) Test site of the spiral waveguides including the GaAs/Si waveguide, the Si waveguide, and the waveguide transition. (b) The GaAs/Si waveguide region, red-colored rectangle. (c) The waveguide transition region from the Si to the GaAs/Si waveguide, blue-colored rectangle. (d) The measured transmission of the REF waveguide, Spiral 01, and Spiral 02.
    (a) Propagation loss of the GaAs/Si waveguide and (b) the insertion loss of the waveguide transition.
    Fig. 12. (a) Propagation loss of the GaAs/Si waveguide and (b) the insertion loss of the waveguide transition.
    (a) Optical power versus applied voltage for the OMA definition and (b) the comparison of the OMA versus the phase shifter length between the GaAs/Si and the Si modulators.
    Fig. 13. (a) Optical power versus applied voltage for the OMA definition and (b) the comparison of the OMA versus the phase shifter length between the GaAs/Si and the Si modulators.
     lGaAs [μm]lSi [μm]nWT
    Spiral 011561643936
    Spiral 029990501036
    Table 1. Parameter Values of Waveguide Lengths and Number of Waveguide Transitions for Spiral 01 and Spiral 02
    Younghyun Kim, Didit Yudistira, Bernardette Kunert, Marina Baryshnikova, Reynald Alcotte, Cenk Ibrahim Ozdemir, Sanghyeon Kim, Sebastien Lardenois, Peter Verheyen, Joris Van Campenhout, Marianna Pantouvaki. Monolithic GaAs/Si V-groove depletion-type optical phase shifters integrated in a 300 mm Si photonics platform[J]. Photonics Research, 2022, 10(6): 1509
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