Optical pulses are fundamentally defined by their temporal and spectral properties.The ability to control pulse properties allows practitioners to efficiently leverage them for advanced metrology,high speed optical co...Optical pulses are fundamentally defined by their temporal and spectral properties.The ability to control pulse properties allows practitioners to efficiently leverage them for advanced metrology,high speed optical communications and attosecond science.Here,we report 11×temporal compression of 5.8 ps pulses to 0.55 ps using a low power of 13.3 W.The result is accompanied by a significant increase in the pulse peak power by 9.4×.These results represent the strongest temporal compression demonstrated to date on a complementary metal–oxide–semiconductor(CMOS)chip.In addition,we report the first demonstration of on-chip spectral compression,3.0×spectral compression of 480 fs pulses,importantly while preserving the pulse energy.The strong compression achieved at low powers harnesses advanced on-chip device design,and the strong nonlinear properties of backend-CMOS compatible ultra-silicon-rich nitride,which possesses absence of two-photon absorption and 500×larger nonlinear parameter than in stoichiometric silicon nitride waveguides.The demonstrated work introduces an important new paradigm for spectro-temporal compression of optical pulses toward turn-key,on-chip integrated systems for all-optical pulse control.展开更多
Spectral tunability methods used in optical communications and signal processing leveraging optical,electrical,and acousto-optic effects typically involve spectral truncation that results in energy loss.Here we demons...Spectral tunability methods used in optical communications and signal processing leveraging optical,electrical,and acousto-optic effects typically involve spectral truncation that results in energy loss.Here we demonstrate temperature tunable spectral broadening using a nonlinear ultra-silicon-rich nitride device consisting of a 3-mm-long cladding-modulated Bragg grating and a 7-mm-long nonlinear channel waveguide.By operating at frequencies close to the grating band edge,in an apodized Bragg grating,we access strong grating-induced dispersion while maintaining low losses and high transmissivity.We further exploit the redshift in the Bragg grating stopband due to the thermo-optic effect to achieve tunable dispersion,leading to varying degrees of soliton-effect compression and self-phase-modulation-induced spectral broadening.We observe an increase in the bandwidth of the output pulse spectrum from 69 to 106 nm as temperature decreases from 70℃ to 25℃,in good agreement with simulated results using the generalized nonlinear Schrödinger equation.The demonstrated approach provides a new avenue to achieve on-chip laser spectral tuning without loss in pulse energy.展开更多
基金supported by the National Research Foundation Competitive Research Grant(NRF-CRP18-2017-03)the MOE ACRF Tier 2 Grant.
文摘Optical pulses are fundamentally defined by their temporal and spectral properties.The ability to control pulse properties allows practitioners to efficiently leverage them for advanced metrology,high speed optical communications and attosecond science.Here,we report 11×temporal compression of 5.8 ps pulses to 0.55 ps using a low power of 13.3 W.The result is accompanied by a significant increase in the pulse peak power by 9.4×.These results represent the strongest temporal compression demonstrated to date on a complementary metal–oxide–semiconductor(CMOS)chip.In addition,we report the first demonstration of on-chip spectral compression,3.0×spectral compression of 480 fs pulses,importantly while preserving the pulse energy.The strong compression achieved at low powers harnesses advanced on-chip device design,and the strong nonlinear properties of backend-CMOS compatible ultra-silicon-rich nitride,which possesses absence of two-photon absorption and 500×larger nonlinear parameter than in stoichiometric silicon nitride waveguides.The demonstrated work introduces an important new paradigm for spectro-temporal compression of optical pulses toward turn-key,on-chip integrated systems for all-optical pulse control.
基金National Research Foundation Competitive Research Grant(NRF-CRP18-2017-03)Ministry of Education ACRF Tier 2 Grant.
文摘Spectral tunability methods used in optical communications and signal processing leveraging optical,electrical,and acousto-optic effects typically involve spectral truncation that results in energy loss.Here we demonstrate temperature tunable spectral broadening using a nonlinear ultra-silicon-rich nitride device consisting of a 3-mm-long cladding-modulated Bragg grating and a 7-mm-long nonlinear channel waveguide.By operating at frequencies close to the grating band edge,in an apodized Bragg grating,we access strong grating-induced dispersion while maintaining low losses and high transmissivity.We further exploit the redshift in the Bragg grating stopband due to the thermo-optic effect to achieve tunable dispersion,leading to varying degrees of soliton-effect compression and self-phase-modulation-induced spectral broadening.We observe an increase in the bandwidth of the output pulse spectrum from 69 to 106 nm as temperature decreases from 70℃ to 25℃,in good agreement with simulated results using the generalized nonlinear Schrödinger equation.The demonstrated approach provides a new avenue to achieve on-chip laser spectral tuning without loss in pulse energy.
