This paper presents a wavelength-stepped swept laser based on a dispersion-tuned swept laser with the integration of a Mach-Zehnder interferometer,enabling a transition from continuous wavelength sweeping to wavelengt...This paper presents a wavelength-stepped swept laser based on a dispersion-tuned swept laser with the integration of a Mach-Zehnder interferometer,enabling a transition from continuous wavelength sweeping to wavelengthstepped sweeping.A comprehensive investigation of this laser is conducted,wherein different modulation schemes are employed to dynamically compare the switching mode,static-sweeping mode,and sweeping mode;the absence of mode hopping in the sweeping mode of the laser is verified.However,it is observed during experiments that the wavelength always remains stationary for a long time during the initiation of sweeping and change in sweeping direction,exhibiting latency compared to the modulation frequency variations.Through a simplistic modeling analysis of the composite cavity,it is revealed that the detuned state of the sub-cavity plays a critical role in the stable operation of the laser.Subsequently,simulation verification using the Ginzburg-Landau equation supports this observation.Additionally,compared to dispersion-tuned swept lasers,not only the linewidth significantly is narrowed in the proposed laser,but it also demonstrates enhanced stability during the sweeping process.This study provides,to our knowledge,a new laser source for ultra-fast optical imaging,ranging,and sensing applications,and presents novel methods and theoretical models for linewidth compression in swept lasers.展开更多
基金National Key Research and Development Program of China(2023YFF0715700)Fundamental Research Funds for the Central Universities(2023CDJKYJH064)Chongqing Talents:Exceptional Young Talents Project(CQYC202005011)。
文摘This paper presents a wavelength-stepped swept laser based on a dispersion-tuned swept laser with the integration of a Mach-Zehnder interferometer,enabling a transition from continuous wavelength sweeping to wavelengthstepped sweeping.A comprehensive investigation of this laser is conducted,wherein different modulation schemes are employed to dynamically compare the switching mode,static-sweeping mode,and sweeping mode;the absence of mode hopping in the sweeping mode of the laser is verified.However,it is observed during experiments that the wavelength always remains stationary for a long time during the initiation of sweeping and change in sweeping direction,exhibiting latency compared to the modulation frequency variations.Through a simplistic modeling analysis of the composite cavity,it is revealed that the detuned state of the sub-cavity plays a critical role in the stable operation of the laser.Subsequently,simulation verification using the Ginzburg-Landau equation supports this observation.Additionally,compared to dispersion-tuned swept lasers,not only the linewidth significantly is narrowed in the proposed laser,but it also demonstrates enhanced stability during the sweeping process.This study provides,to our knowledge,a new laser source for ultra-fast optical imaging,ranging,and sensing applications,and presents novel methods and theoretical models for linewidth compression in swept lasers.
