Work

Superior ultrafast laser-inscribed photonic-lantern mode (de)multiplexers using trajectory-asymmetry with uniform waveguides

Year: 2024

Type: article

Abstract: Femtosecond laser fabrication technology has been applied to photonic-lantern mode (de)multiplexers owing to its 3D fabrication capability.Current photonic-lantern mode (de)multiplexer designs based on femtosecond laser fabrication technology mostly follow a fibre-type photonic lantern design, which uses trajectory-symmetry structures with non-uniform waveguides for selective mode excitation.However, non-uniform waveguides can lead to inconsistent waveguide transmission and coupling losses.Trajectory-symmetry designs are inefficient for selective-mode excitation.Therefore, we optimised the design using trajectory asymmetry with uniform waveguides and fabricated superior ultrafast laser-inscribed photonic-lantern mode (de)multiplexers.Consistent waveguide transmission and coupling losses (0.1 dB/cm and 0.2 dB/facet, respectively) at 1550 nm were obtained on uniform single-mode waveguides.Based on the trajectory-asymmetry design for photonic-lantern mode (de)multiplexers, efficient mode excitation ( , , and ) with average insertion losses as low as 1 dB at 1550 nm was achieved, with mode-dependent losses of less than 0.3 dB.The photonic-lantern design was polarisation-insensitive, and the polarisation-determined losses were less than 0.2 dB.Along with polarisation multiplexing realised by fibre-type polarisation beam splitters, six signal channels ( , , , , , and ), each carrying 42 Gaud/s quadrature phase-shift keying signals, were transmitted through a few-mode fibre for optical transmission.The average insertion loss of the system is less than 5 dB, while its maximum crosstalk with the few-mode fibre is less than -12 dB, leading to a 4-dB power penalty.The findings of this study pave the way for the practical application of 3D integrated photonic chips in high-capacity optical transmission systems.

Source: Light Advanced Manufacturing

DOI: 10.37188/lam.2025.002

Authors: Chengkun Cai, Min Yang, Guofeng Yan, Kang Li, Kangrui Wang, Jian Wang

Institutions: Wuhan National Laboratory for Optoelectronics, Optics Valley Laboratory, Huazhong University of Science and Technology

Language: English

Topic: Laser Material Processing Techniques

Subfield: Computational Mechanics

Field: Engineering

Domain: Physical Sciences

Open Access status: diamond

Funders: National Natural Science Foundation of China, Huazhong University of Science and Technology, Natural Science Foundation of Hubei Province

Awards: G160318281, G3248731661, G431074200, G4365663544