Ultra-high-pulse-repetition-rate lasers are essential for a number of applications, including, e.g., optical communication and ablation-cooled material processing. Despite several techniques to generate pulses with gi...Ultra-high-pulse-repetition-rate lasers are essential for a number of applications, including, e.g., optical communication and ablation-cooled material processing. Despite several techniques to generate pulses with gigahertzrange repetition rate, incorporating mainly short-length resonators, more widespread applications are still limited by the lack of a robust, simple, and cost-effective solution. Here, we report for the first time, to the best of our knowledge, fully passive harmonic mode locking in an all-polarization-maintaining(PM) fiber laser. The design guarantees a fixed polarization state and stable operation, where the cavity harmonic number is controlled by the pump power only. Self-starting operation is provided by the antimony telluride(Sb2Te3) thin-film saturable absorber(SA), which facilitates multiple pulse operation. The SA acts by means of low modulation depth, low saturation fluence, and an inverse slope in the saturable absorption curve. The optimum features of the SA and limiting factors for high-repetition-rate pulse generation in this regime of operation are discussed. As a result, 2.2 ps pulses with 3 GHz repetition rate are generated at 1560 nm wavelength. The study reports a new approach towards an optimal SA for multi-gigahertz pulse generation in practical, all-PM fiber lasers.展开更多
In this work pulse generation in both the 1.5 and 2 μm spectral ranges using a graphene oxide(GO)-paper-based saturable absorber in Er-and Tm-doped fiber lasers is presented. The article describes the fabrication met...In this work pulse generation in both the 1.5 and 2 μm spectral ranges using a graphene oxide(GO)-paper-based saturable absorber in Er-and Tm-doped fiber lasers is presented. The article describes the fabrication method of GO paper and its characterization. The performance of both lasers is discussed in detail. Stable, mode-locked operation provides 613 fs and 1.36 ps soliton pulses centered at 1565.9 and 1961.6 nm in Er-and Tm-doped fiber lasers, respectively. Furthermore, scaling of spectral width, and hence the pulse duration, by increasing the number of GO paper layers in the Er-doped laser is described. The versatility and simplicity of GO paper fabrication combined with the possibility of scaling the optical spectrum full width at half-maximum are essential features that make it a good candidate for ultrafast low-power mode-locked lasers operating in different spectral regions.展开更多
基金Narodowe Centrum Nauki(2014/13/N/ST7/01968,2016/23/D/ST8/02686)Politechnika Wroclawska(0401/0030/18)Fundacja na rzecz Nauki Polskiej(FNP)(POIR.04.04.00-00-3D47/16-00)
文摘Ultra-high-pulse-repetition-rate lasers are essential for a number of applications, including, e.g., optical communication and ablation-cooled material processing. Despite several techniques to generate pulses with gigahertzrange repetition rate, incorporating mainly short-length resonators, more widespread applications are still limited by the lack of a robust, simple, and cost-effective solution. Here, we report for the first time, to the best of our knowledge, fully passive harmonic mode locking in an all-polarization-maintaining(PM) fiber laser. The design guarantees a fixed polarization state and stable operation, where the cavity harmonic number is controlled by the pump power only. Self-starting operation is provided by the antimony telluride(Sb2Te3) thin-film saturable absorber(SA), which facilitates multiple pulse operation. The SA acts by means of low modulation depth, low saturation fluence, and an inverse slope in the saturable absorption curve. The optimum features of the SA and limiting factors for high-repetition-rate pulse generation in this regime of operation are discussed. As a result, 2.2 ps pulses with 3 GHz repetition rate are generated at 1560 nm wavelength. The study reports a new approach towards an optimal SA for multi-gigahertz pulse generation in practical, all-PM fiber lasers.
基金supported by the Polish Ministry of Science and Higher Education under the project entitled “Investigation of saturable absorbers based on graphene oxide and reduced graphene oxide” (project no. IP2012 052072)supported by the National Science Centre (NCN, Poland) under the project “Passive mode synchronization in fiber lasers based on low-dimensional materials—simulations and experiments” (decision no. DEC2014/13/N/ST7/01968)
文摘In this work pulse generation in both the 1.5 and 2 μm spectral ranges using a graphene oxide(GO)-paper-based saturable absorber in Er-and Tm-doped fiber lasers is presented. The article describes the fabrication method of GO paper and its characterization. The performance of both lasers is discussed in detail. Stable, mode-locked operation provides 613 fs and 1.36 ps soliton pulses centered at 1565.9 and 1961.6 nm in Er-and Tm-doped fiber lasers, respectively. Furthermore, scaling of spectral width, and hence the pulse duration, by increasing the number of GO paper layers in the Er-doped laser is described. The versatility and simplicity of GO paper fabrication combined with the possibility of scaling the optical spectrum full width at half-maximum are essential features that make it a good candidate for ultrafast low-power mode-locked lasers operating in different spectral regions.
