1.5-μm波段25-GHz重频亚皮秒脉冲输出半导体锁模激光器(特邀)

25-GHz Semiconductor Mode-locked Laser with Subpicosecond Pulse Output in the 1.5-μm Band(Invited)

针对高速光采样、光频梳以及光通信系统应用,研制了1.5μm波段高重频超短脉冲输出半导体锁模激光器。基于AlGaInAs/InP材料体系,采用两段式单片集成锁模结构,引入稀释波导结构,综合降低光限制因子、提升材料饱和能量、降低腔内损耗,从而降低有源区色散对脉冲的影响并提升脉冲峰值功率,最终在1.5μm波段实现了重复频率24.3 GHz、脉冲宽度680 fs的亚皮秒光脉冲输出,脉冲光谱宽度为7.2 nm,脉冲峰值能量为525 mW。

Ultrashort optical pulse sources have important applications in optical analog-to-digital conversion,optical fiber communication,optical THz communication,microwave photonics and other systems.Mode-locking technology is a common method for generating ultrashort pulses.Various types of mode-locked lasers,such as solid-state mode-locked lasers,fiber mode-locked lasers,and semiconductor mode-locked lasers,can be used to generate short pulse outputs with different repetition frequencies.In optical analog-to-digital conversion systems and optical fiber communication systems,it is usually desired that the sampling light source or multi-wavelength light source has the characteristics of high repetition frequency,short pulse,small size,low cost,and mass production.Semiconductor mode-locked lasers are ideal light sources that meet the above requirements.A 1.5μm high repetition frequency ultrashort optical pulse source based on a semiconductor mode-locked laser is developed for applications such as high-speed optical sampling,optical frequency comb and optical communication system.By adopting the AlGaInAs/InP material system,a two-section monolithic integrated mode-locking structure with a dilution waveguide layer is developed to decrease the optical confinement factor,increase the saturation energy,reduce the cavity loss,so as to reduce the influence of the gain dispersion and increase the peak pulse power.Finally,a subpicosecond optical pulse with a repetition rate of 24.3 GHz and pulse width of 680 fs is achieved in 1.5μm band,with a spectral width of 7.2 nm and a peak pulse energy of 525 mW.