Breaking the bandwidth-efficiency trade-off in modified uni-travelling-carrier photodiodes

Yijun Guo; Xingjun Wang

doi:10.1088/1674-4926/26020029

J. Semicond. > Just Accepted

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Breaking the bandwidth-efficiency trade-off in modified uni-travelling-carrier photodiodes

Yijun Guo and Xingjun Wang

+ Author Affiliations

Corresponding author: Xingjun Wang, xjwang@pku.edu.cn

DOI: 10.1088/1674-4926/26020029CSTR: 32376.14.1674-4926.26020029

References

[1]	Nagatsuma T, Ducournau G, Renaud C C. Advances in terahertz communications accelerated by photonics. Nat Photonics, 2016, 10(6): 371 doi: 10.1038/nphoton.2016.65
[2]	Zhang H Q, Zhang L, Wang S W, et al. Tbit/s multi-dimensional multiplexing THz-over-fiber for 6G wireless communication. J Light Technol, 2021, 39(18): 5783 doi: 10.1109/JLT.2021.3093628
[3]	Tao Z H, Wang H Y, Feng H K, et al. Ultrabroadband on-chip photonics for full-spectrum wireless communications. Nature, 2025, 645(8079): 80 doi: 10.1038/s41586-025-09451-8
[4]	Zhang Y H, Shu H W, Guo Y J, et al. Integrated photonics enabling ultra-wideband fibre–wireless communication. Nature, 2026, 651(8105): 348 doi: 10.1038/s41586-026-10172-9
[5]	Wun J M, Wang Y W, Shi J W. Ultrafast uni-traveling carrier photodiodes with GaAs_0.5Sb_0.5/In_0.53Ga_0.47As type-II hybrid absorbers for high-power operation at THz frequencies. IEEE J Sel Top Quantum Electron, 2018, 24(2): 8500207 doi: 10.1109/jstqe.2017.2741106
[6]	Ito H, Furuta T, Kodama S, et al. InP/InGaAs uni-travelling-carrier photodiode with310 GHz bandwidth. Electron Lett, 2000, 36(21): 1809 doi: 10.1049/el:20001274
[7]	Rouvalis E, Chtioui M, van Dijk F, et al. 170 GHz uni-traveling carrier photodiodes for InP-based photonic integrated circuits. Opt Express, 2012, 20(18): 20090 doi: 10.1364/OE.20.020090
[8]	Li L Z, Wang L Y, Long T Y, et al. Ultra-fast waveguide MUTC photodiodes over 220 GHz. J Lightwave Technol, 2024, 42(21): 7451 doi: 10.1109/JLT.2024.3379188
[9]	Kato K, Kozen A, Muramoto Y, et al. 110-GHz, 50%-efficiency mushroom-mesa waveguide p-i-n photodiode for a 1.55-μm wavelength. IEEE Photon Technol Lett, 1994, 6(6): 719 doi: 10.1109/68.300173
[10]	Li L Z, et al. Modified uni-travelling-carrier photodiodes with 206 GHz bandwidth and 0.81 AW⁻¹ external responsivity. Nature Photonics 2025, 1-8

Fig. 1. (Color online) THz waveguide-integrated MUTC-PD. a, Schematic of the device. b–c, Frequency response from a heterodyne measurement setup of the 2 × 7 μm² device at 1.5-mA photocurrent (b), 2 × 15 μm² device at 3-mA photocurrent (c). d, Simulated electric field distributions at various photocurrents for the 2 × 15 μm² device under a –1.5-V bias. e, Frequency response of the packaged module under different photocurrents from 120 GHz to 220 GHz. f, RF power versus photocurrent for MUTC-PDs with different lengths at 180 GHz under a –1.5-V bias. g, BER versus photocurrent for 30-Gbaud QPSK/16-QAM signal at a carrier frequency of 150 GHz. h, Performance comparison of waveguide-coupled and surface-illuminated PDs^[10].

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[1]	Nagatsuma T, Ducournau G, Renaud C C. Advances in terahertz communications accelerated by photonics. Nat Photonics, 2016, 10(6): 371 doi: 10.1038/nphoton.2016.65
[2]	Zhang H Q, Zhang L, Wang S W, et al. Tbit/s multi-dimensional multiplexing THz-over-fiber for 6G wireless communication. J Light Technol, 2021, 39(18): 5783 doi: 10.1109/JLT.2021.3093628
[3]	Tao Z H, Wang H Y, Feng H K, et al. Ultrabroadband on-chip photonics for full-spectrum wireless communications. Nature, 2025, 645(8079): 80 doi: 10.1038/s41586-025-09451-8
[4]	Zhang Y H, Shu H W, Guo Y J, et al. Integrated photonics enabling ultra-wideband fibre–wireless communication. Nature, 2026, 651(8105): 348 doi: 10.1038/s41586-026-10172-9
[5]	Wun J M, Wang Y W, Shi J W. Ultrafast uni-traveling carrier photodiodes with GaAs_0.5Sb_0.5/In_0.53Ga_0.47As type-II hybrid absorbers for high-power operation at THz frequencies. IEEE J Sel Top Quantum Electron, 2018, 24(2): 8500207 doi: 10.1109/jstqe.2017.2741106
[6]	Ito H, Furuta T, Kodama S, et al. InP/InGaAs uni-travelling-carrier photodiode with310 GHz bandwidth. Electron Lett, 2000, 36(21): 1809 doi: 10.1049/el:20001274
[7]	Rouvalis E, Chtioui M, van Dijk F, et al. 170 GHz uni-traveling carrier photodiodes for InP-based photonic integrated circuits. Opt Express, 2012, 20(18): 20090 doi: 10.1364/OE.20.020090
[8]	Li L Z, Wang L Y, Long T Y, et al. Ultra-fast waveguide MUTC photodiodes over 220 GHz. J Lightwave Technol, 2024, 42(21): 7451 doi: 10.1109/JLT.2024.3379188
[9]	Kato K, Kozen A, Muramoto Y, et al. 110-GHz, 50%-efficiency mushroom-mesa waveguide p-i-n photodiode for a 1.55-μm wavelength. IEEE Photon Technol Lett, 1994, 6(6): 719 doi: 10.1109/68.300173
[10]	Li L Z, et al. Modified uni-travelling-carrier photodiodes with 206 GHz bandwidth and 0.81 AW⁻¹ external responsivity. Nature Photonics 2025, 1-8