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...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 LPa11 LPb11 LP01(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 LPa11x LPa11y LPb11x LPb11y LP01xmultiplexing realised by fibre-type polarisation beam splitters,six signal channels(,,,,,LP01yand),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.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(62125503,62261160388)the Natural Science Foundation of Hubei Province of China(2023AFA028)the Innovation Project of Optics Valley Laboratory(OVL2021BG004).
文摘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 LPa11 LPb11 LP01(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 LPa11x LPa11y LPb11x LPb11y LP01xmultiplexing realised by fibre-type polarisation beam splitters,six signal channels(,,,,,LP01yand),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.
