The pulse energy in the ultrafast soliton fiber laser oscillators is usually limited by the well-known wave-breaking phenomenon owing to the absence era desirable real saturable absorber （SA） with high power toleran...The pulse energy in the ultrafast soliton fiber laser oscillators is usually limited by the well-known wave-breaking phenomenon owing to the absence era desirable real saturable absorber （SA） with high power tolerance and large modulation depth. Here, we report a type of microfiber-based MoTe2 SA fabricated by the magnetron-sputtering deposition （MSD） method. High-energy wave-breaking free soliton pulses were generated with pulse duration/pulse energy/average output power of 229 fs/2.14 nJ/57 mW in the 1.5 μm regime and 1.3 ps/13.8 nJ/ 212 mW in the 2 μm regime, respectively. To our knowledge, the generated soliton pulses at 1.5μm had the shortest pulse duration and the highest output power among the reported erbium-doped fiber lasers mode locked by transition metal dichalcogenides. Moreover, this was the first demonstration of a MoTe2-based SA in fiber lasers in the 2 ltm regime, and the pulse energy/output power are the highest in the reported thulium-doped fiber lasers mode locked by two-dlmensional materials. Our results suggest that a microfiber-based MoTe2 SA could be used as an excellent photonic device for ultrafast pulse generation, and the MSD technique opens a promising route to produce a high-performance SA with high power tolerance and large modulation depth, which are beneficial for high-energy wave-breaking free pulse generation.展开更多
We reported diverse soliton operations in a thulium/holmium-doped fiber laser by taking advantage of a tapered fiber-based topological insulator（TI） Bi2Te3 saturable absorber（SA）.The SA had a nonsaturable loss of ...We reported diverse soliton operations in a thulium/holmium-doped fiber laser by taking advantage of a tapered fiber-based topological insulator（TI） Bi2Te3 saturable absorber（SA）.The SA had a nonsaturable loss of 53.5% and a modulation depth of 9.8%.Stable fundamentally mode-locked solitons at 1909.5 nm with distinct Kelly sidebands on the output spectrum,a pulse repetition rate of 21.5 MHz,and a measured pulse width of 1.26 ps were observed in the work.By increasing the pump power,both bunched solitons with soliton number up to 15 and harmonically mode-locked solitons with harmonic order up to 10 were obtained.To our knowledge,this is the first report of both bunched solitons and harmonically mode-locked solitons in a fiber laser at 2 μm region incorporated with TIs.展开更多
Passively mode-locked fiber lasers emit femtosecond pulse trains with excellent short-term stability. The quantum-limited timing jitter of a free running femtosecond erbium-doped fiber laser working at room temperatur...Passively mode-locked fiber lasers emit femtosecond pulse trains with excellent short-term stability. The quantum-limited timing jitter of a free running femtosecond erbium-doped fiber laser working at room temperature is considerably below one femtosecond at high Fourier frequency. The ultrashort pulse train with ultralow timing jitter enables absolute time-of-flight measurements based on a dual-comb implementation, which is typically composed of a pair of optical frequency combs generated by femtosecond lasers. Dead-zone-free absolute distance measurement with sub-micrometer precision and kHz update rate has been routinely achieved with a dual-comb configuration, which is promising for a number of precision manufacturing applications, from large step-structure measurements prevalent in microelectronic profilometry to three coordinate measurements in large-scale aerospace manufacturing and shipbuilding. In this paper, we first review the sub-femtosecond precision timing jitter characterization methods and approaches for ultralow timing jitter mode-locked fiber laser design. Then, we provide an overview of the state-of-the-art dual-comb absolute ranging technology in terms of working principles, experimental implementations, and measurement precisions. Finally, we discuss the impact of quantum-limited timing jitter on the dual-comb ranging precision at a high update rate. The route to highprecision dual-comb range finder design based on ultralow jitter femtosecond fiber lasers is proposed.展开更多
The performance of fiber mode-locked lasers is limited due to the high nonlinearity induced by the spatial confinement of the single-mode fiber core.To massively increase the pulse energy of the femtosecond pulses,amp...The performance of fiber mode-locked lasers is limited due to the high nonlinearity induced by the spatial confinement of the single-mode fiber core.To massively increase the pulse energy of the femtosecond pulses,amplification is performed outside the oscillator.Recently,spatiotemporal mode-locking has been proposed as a new path to fiber lasers.However,the beam quality was highly multimode,and the calculated threshold pulse energy(>100 nJ)for nonlinear beam self-cleaning was challenging to realize.We present an approach to reach high energy per pulse directly in the mode-locked multimode fiber oscillator with a near single-mode output beam.Our approach relies on spatial beam self-cleaning via the nonlinear Kerr effect,and we demonstrate a multimode fiber oscillator with M^2<1.13 beam profile,up to 24 nJ energy,and sub-100 fs compressed duration.Nonlinear beam self-cleaning is verified both numerically and experimentally for the first time in a mode-locked multimode laser cavity.The reported approach is further power scalable with larger core sized fibers up to a certain level of modal dispersion and could benefit applications that require high-power ultrashort lasers with commercially available optical fibers.展开更多
分别将氧化石墨烯可饱和吸收镜(GOSAM)与半导体可饱和吸收镜(SESAM)作为可饱和吸收体,在同一掺铒光纤激光器中均实现了全光纤结构、稳定的锁模飞秒脉冲输出。实验用抽运源为中心波长974 nm的半导体激光器,抽运1.4 m长的吸收率为7 d B/m...分别将氧化石墨烯可饱和吸收镜(GOSAM)与半导体可饱和吸收镜(SESAM)作为可饱和吸收体,在同一掺铒光纤激光器中均实现了全光纤结构、稳定的锁模飞秒脉冲输出。实验用抽运源为中心波长974 nm的半导体激光器,抽运1.4 m长的吸收率为7 d B/m的掺铒光纤,谐振腔总腔长约为12 m。以GOSAM作为可饱和吸收体,当抽运功率为29 m W时,激光器产生稳定的锁模脉冲输出,脉冲宽度最窄为703 fs,光谱中心波长为1557.67 nm,3 d B带宽为3.91 nm。使用调制深度为18%的SESAM作为可饱和吸收体,当抽运功率为32 m W时也可得到锁模脉冲,脉冲宽度为542 fs,光谱中心波长为1561.5 nm,3 d B带宽为5.41 nm。实验表明,新型激光锁模器件氧化石墨烯的可饱和吸收效应可与SESAM媲美,且兼具价格低廉、制备简单的优势,在实现超短脉冲运转方面具有广阔的实际应用前景。展开更多
In this paper, tin disulfide （SnS2）, a two-dimensional （2D） n-type direct bandgap layered metal dichalcogenide with a gap value of 2.24 eV, was employed as a saturable absorber. Its appearance and nonlinear satura...In this paper, tin disulfide （SnS2）, a two-dimensional （2D） n-type direct bandgap layered metal dichalcogenide with a gap value of 2.24 eV, was employed as a saturable absorber. Its appearance and nonlinear saturable ab- sorption characteristics were also investigated experimentally. SnSz-PVA （polyvinyl alcohol） film was successfully prepared and employed as a mode-locker for achieving a mode-locked Er-doped fiber laser with a pulse width of 623 fs at a pulse repetition rate of 29.33 MHz. The results prove that SnS2 nanosheets will have wide potential ultrafast photonic applications due to their suitable bandgap value and excellent nonlinear saturable absorption characteristics.展开更多
Stable 68 fs pulses with the average power of 1.5 W is directly generated from a multimode diode-pumped Kerr-lens mode-locked Yb:CYA laser by separating the gain medium and Kerr medium. The repetition rate is about 50...Stable 68 fs pulses with the average power of 1.5 W is directly generated from a multimode diode-pumped Kerr-lens mode-locked Yb:CYA laser by separating the gain medium and Kerr medium. The repetition rate is about 50 MHz, resulting in a single pulse energy of 30 n J and a peak power of 0.44 MW. To the best of our knowledge, this is the highest single pulse energy ever produced from a mode-locked Yb:CYA oscillator. Our experimental results show that Yb:CYA crystal is an excellent candidate for multiwatt, sub-100 fs pulse generation in diode-pumped all-solid-state lasers. It is believed that the output power can be scalable to multi-W while the pulse duration is maintained with this simple method.展开更多
Ultrafast lasers generating high-repetition-rate ultrashort pulses through various mode-locking methods can benefit many important applications,including communications,materials processing,astronomical observation,et...Ultrafast lasers generating high-repetition-rate ultrashort pulses through various mode-locking methods can benefit many important applications,including communications,materials processing,astronomical observation,etc.For decades,mode-locking based on dissipative four-wave-mixing(DFWM)has been fundamental in producing pulses with repetition rates on the order of gigahertz(GHz),where multiwavelength comb filters and long nonlinear components are elemental.Recently,this method has been improved using filter-driven DFWM,which exploits both the filtering and nonlinear features of silica microring resonators.However,the fabrication complexity and coupling loss between waveguides and fibers are problematic.We demonstrate a tens-to hundreds-of gigahertz-stable pulsed all-fiber laser based on a hybrid plasmonic microfiber knot resonator device.Unlike previously reported pulse generation mechanisms,the operation utilizes the nonlinear-polarization-rotation(NPR)effect introduced by the polarization-dependent feature of the device to increase intracavity power for boosting DFWM mode-locking,which we term NPRstimulated DFWM.The easily fabricated versatile device acts as a polarizer,comb filter,and nonlinear component simultaneously,thereby introducing an application of microfiber resonator devices in ultrafast and nonlinear photonics.We believe that our work underpins a significant improvement in achieving practical low-cost ultrafast light sources.展开更多
In this paper,both nonlinear saturable absorption and two-photon absorption（TPA） of few-layer molybdenum diselenide（MoSe2） were observed at 1.56 μm wavelength and further applied to mode-locked ultrafast fiber la...In this paper,both nonlinear saturable absorption and two-photon absorption（TPA） of few-layer molybdenum diselenide（MoSe2） were observed at 1.56 μm wavelength and further applied to mode-locked ultrafast fiber laser for the first time to our knowledge.Few-layer MoSe2 nanosheets were prepared by liquid-phase exfoliation method and characterized by x ray diffractometer,Raman spectroscopy,and atomic force microscopy.The obtained fewlayer MoSe2 dispersion is further composited with a polymer material for convenient fabrication of MoSe2 thin films.Then,we investigated the nonlinear optical（NLO） absorption property of the few-layer MoSe2 film using a balanced twin-detector measurement technique.Both the saturable absorption and TPA effects of the few-layer MoSe2 film were found by increasing the input optical intensity.The saturable absorption shows a modulation depth of 0.63% and a low nonsaturable loss of 3.5%,corresponding to the relative modulation depth of 18%.The TPA effect occurred when the input optical intensity exceeds 260 MW∕cm2.Furthermore,we experimentally exploit the saturable absorption of few-layer MoSe2 film to mode lock an all-fiber erbium-doped fiber laser.Stable soliton mode locking at 1558 nm center wavelength is achieved with pulse duration of 1.45 ps.It was also observed that the TPA process suppresses the mode-locking operation in the case of higher optical intensity.Our results indicate that layered MoSe2,as another two-dimensional nanomaterial,can provide excellent NLO properties（e.g.,saturable absorption and TPA） for potential applications in ultrashort pulse generation and optical limiting.展开更多
We experimentally demonstrated a diode-pumped Kerr-lens mode-locked femtosecond laser with a Yb:CaYAlO4 crystal as the gain medium. Pulse duration as short as 33 fs was obtained directly from the oscillator at a repet...We experimentally demonstrated a diode-pumped Kerr-lens mode-locked femtosecond laser with a Yb:CaYAlO4 crystal as the gain medium. Pulse duration as short as 33 fs was obtained directly from the oscillator at a repetition rate of 115 MHz. The central wavelength was at 1059 nm with a spectral bandwidth of 49 nm. These are, to the bestof our knowledge, the shortest pulses generated from a Yb:CaYAlO4 oscillator.展开更多
We demonstrated a femtosecond mode-locked Er:Zr F4-Ba F2-La F3-Al F3-Na F(Er:ZBLAN)fiber laser at 2.8μm based on the nonlinear polarization rotation technique.The laser generated an average output power of 317 m W wi...We demonstrated a femtosecond mode-locked Er:Zr F4-Ba F2-La F3-Al F3-Na F(Er:ZBLAN)fiber laser at 2.8μm based on the nonlinear polarization rotation technique.The laser generated an average output power of 317 m W with a repetition rate of 107 MHz and pulse duration as short as 131 fs.To the best of our knowledge,this is the shortest pulse generated directly from a mid-infrared mode-locked Er:ZBLAN fiber laser to date.Numerical simulation and experimental results confirm that reducing the gain fiber length is an effective way to shorten the mode-locked pulse duration in the Er:ZBLAN fiber laser.The work takes an important step towards sub-100-fs mid-infrared pulse generation from mode-locked Er:ZBLAN fiber lasers.展开更多
A passively Q-swithched mode-locked （QML） Tm：LiLuF4 （LLF） laser with a MoS2 saturable absorber （SA） is demonstrated for the first time, to our best knowledge. For the Q-switching mode, the maximum average outp...A passively Q-swithched mode-locked （QML） Tm：LiLuF4 （LLF） laser with a MoS2 saturable absorber （SA） is demonstrated for the first time, to our best knowledge. For the Q-switching mode, the maximum average output power and Q-switched pulse energy are 583 mW and 41.5 μJ, respectively. When the absorbed power is greater than 7.4 W, the passively QML pulse is formed, corresponding to an 83.3-MHz frequency. The modulation depth in Q-switching envelopes is approximately 50%. Results prove that MoS2 is a promising SA for Q-switched and QML solid-state lasers.展开更多
The mode-locked laser diode has emerged as a promising candidate as a signal source for photonic radar systems,wireless data transmission, and frequency comb spectroscopy. They have the advantages of small size, low c...The mode-locked laser diode has emerged as a promising candidate as a signal source for photonic radar systems,wireless data transmission, and frequency comb spectroscopy. They have the advantages of small size, low cost,high reliability, and low power consumption, thanks to semiconductor technology. Mode-locked lasers based on silicon photonics advance these qualities by the use of highly advanced silicon manufacturing technology. This paper will begin by giving an overview of mode-locked laser diode literature, and then focus on mode-locked lasers on silicon. The dependence of mode-locked laser performance on design details is presented.展开更多
We demonstrate an all polarization-maintaining(PM) fiber mode-locked laser seeded, hybrid fiber/solid-slab picosecond pulse laser system which outputs 40 μJ, 10 ps pulses at the central wavelength of 1064 nm. The bea...We demonstrate an all polarization-maintaining(PM) fiber mode-locked laser seeded, hybrid fiber/solid-slab picosecond pulse laser system which outputs 40 μJ, 10 ps pulses at the central wavelength of 1064 nm. The beam quality factors M2 in the unstable and stable directions are 1.35 and 1.31, respectively. 15 μJ picosecond pulses at the central wavelength of 355 nm are generated through third harmonic generation(THG) by using two Li B3 O5(LBO) crystals, in order to get better processing efficiency on polycrystalline diamonds. The high pulse energy and beam quality of these ultraviolet(UV) picosecond pulses are confirmed by latter experiments of material processing on polycrystalline diamonds. This scheme which combines the advantages of the all PM fiber mode-locked laser and the solid-slab amplifier enables compact, robust and chirped pulse amplification-free amplification with high power picosecond pulses.展开更多
基金National Natural Science Foundation of China(NSFC)(11704260,61405126,61605122,61775146)Shenzhen Science and Technology Project(JCY20150324141711695,JCYJ20160427105041864,JSGG20160429114438287,KQJSCX20160226194031,JCYJ20160422103744090)+1 种基金Beijing University of Posts and Telecommunications(BUPT)(IPOC2015B003)Natural Science Foundation of Guangdong Province(2016A030310049,2016A030310059)
文摘The pulse energy in the ultrafast soliton fiber laser oscillators is usually limited by the well-known wave-breaking phenomenon owing to the absence era desirable real saturable absorber （SA） with high power tolerance and large modulation depth. Here, we report a type of microfiber-based MoTe2 SA fabricated by the magnetron-sputtering deposition （MSD） method. High-energy wave-breaking free soliton pulses were generated with pulse duration/pulse energy/average output power of 229 fs/2.14 nJ/57 mW in the 1.5 μm regime and 1.3 ps/13.8 nJ/ 212 mW in the 2 μm regime, respectively. To our knowledge, the generated soliton pulses at 1.5μm had the shortest pulse duration and the highest output power among the reported erbium-doped fiber lasers mode locked by transition metal dichalcogenides. Moreover, this was the first demonstration of a MoTe2-based SA in fiber lasers in the 2 ltm regime, and the pulse energy/output power are the highest in the reported thulium-doped fiber lasers mode locked by two-dlmensional materials. Our results suggest that a microfiber-based MoTe2 SA could be used as an excellent photonic device for ultrafast pulse generation, and the MSD technique opens a promising route to produce a high-performance SA with high power tolerance and large modulation depth, which are beneficial for high-energy wave-breaking free pulse generation.
基金supported by the State Key Program of National Natural Science of China (Grant Nos.61235008,61405254,61340017,and 61435009)the Fundamental Researches Foundation of National University of Defense Technology (Grant No.GDJC13-04)the Hunan Provincial Natural Science Foundation of China (Grant No.14JJ3001)
文摘We reported diverse soliton operations in a thulium/holmium-doped fiber laser by taking advantage of a tapered fiber-based topological insulator（TI） Bi2Te3 saturable absorber（SA）.The SA had a nonsaturable loss of 53.5% and a modulation depth of 9.8%.Stable fundamentally mode-locked solitons at 1909.5 nm with distinct Kelly sidebands on the output spectrum,a pulse repetition rate of 21.5 MHz,and a measured pulse width of 1.26 ps were observed in the work.By increasing the pump power,both bunched solitons with soliton number up to 15 and harmonically mode-locked solitons with harmonic order up to 10 were obtained.To our knowledge,this is the first report of both bunched solitons and harmonically mode-locked solitons in a fiber laser at 2 μm region incorporated with TIs.
基金supported by National Natural Science Foundation of China (Grant Nos.61475162,61675150,and 61535009)Tianjin Natural Science Foundation (Grant No.18JCYBJC16900)Tianjin Research Program of Application Foundation and Advanced Technology (Grant No.17JCJQJC43500)
文摘Passively mode-locked fiber lasers emit femtosecond pulse trains with excellent short-term stability. The quantum-limited timing jitter of a free running femtosecond erbium-doped fiber laser working at room temperature is considerably below one femtosecond at high Fourier frequency. The ultrashort pulse train with ultralow timing jitter enables absolute time-of-flight measurements based on a dual-comb implementation, which is typically composed of a pair of optical frequency combs generated by femtosecond lasers. Dead-zone-free absolute distance measurement with sub-micrometer precision and kHz update rate has been routinely achieved with a dual-comb configuration, which is promising for a number of precision manufacturing applications, from large step-structure measurements prevalent in microelectronic profilometry to three coordinate measurements in large-scale aerospace manufacturing and shipbuilding. In this paper, we first review the sub-femtosecond precision timing jitter characterization methods and approaches for ultralow timing jitter mode-locked fiber laser design. Then, we provide an overview of the state-of-the-art dual-comb absolute ranging technology in terms of working principles, experimental implementations, and measurement precisions. Finally, we discuss the impact of quantum-limited timing jitter on the dual-comb ranging precision at a high update rate. The route to highprecision dual-comb range finder design based on ultralow jitter femtosecond fiber lasers is proposed.
文摘The performance of fiber mode-locked lasers is limited due to the high nonlinearity induced by the spatial confinement of the single-mode fiber core.To massively increase the pulse energy of the femtosecond pulses,amplification is performed outside the oscillator.Recently,spatiotemporal mode-locking has been proposed as a new path to fiber lasers.However,the beam quality was highly multimode,and the calculated threshold pulse energy(>100 nJ)for nonlinear beam self-cleaning was challenging to realize.We present an approach to reach high energy per pulse directly in the mode-locked multimode fiber oscillator with a near single-mode output beam.Our approach relies on spatial beam self-cleaning via the nonlinear Kerr effect,and we demonstrate a multimode fiber oscillator with M^2<1.13 beam profile,up to 24 nJ energy,and sub-100 fs compressed duration.Nonlinear beam self-cleaning is verified both numerically and experimentally for the first time in a mode-locked multimode laser cavity.The reported approach is further power scalable with larger core sized fibers up to a certain level of modal dispersion and could benefit applications that require high-power ultrashort lasers with commercially available optical fibers.
文摘分别将氧化石墨烯可饱和吸收镜(GOSAM)与半导体可饱和吸收镜(SESAM)作为可饱和吸收体,在同一掺铒光纤激光器中均实现了全光纤结构、稳定的锁模飞秒脉冲输出。实验用抽运源为中心波长974 nm的半导体激光器,抽运1.4 m长的吸收率为7 d B/m的掺铒光纤,谐振腔总腔长约为12 m。以GOSAM作为可饱和吸收体,当抽运功率为29 m W时,激光器产生稳定的锁模脉冲输出,脉冲宽度最窄为703 fs,光谱中心波长为1557.67 nm,3 d B带宽为3.91 nm。使用调制深度为18%的SESAM作为可饱和吸收体,当抽运功率为32 m W时也可得到锁模脉冲,脉冲宽度为542 fs,光谱中心波长为1561.5 nm,3 d B带宽为5.41 nm。实验表明,新型激光锁模器件氧化石墨烯的可饱和吸收效应可与SESAM媲美,且兼具价格低廉、制备简单的优势,在实现超短脉冲运转方面具有广阔的实际应用前景。
基金National Natural Science Foundation of China(NSFC)(11474187,61205174,61475089)China Postdoctoral Science Foundation(2016M602177)Natural Science Foundation of Shandong Province,China(ZR2014FM028,ZR2016FP01)
文摘In this paper, tin disulfide （SnS2）, a two-dimensional （2D） n-type direct bandgap layered metal dichalcogenide with a gap value of 2.24 eV, was employed as a saturable absorber. Its appearance and nonlinear saturable ab- sorption characteristics were also investigated experimentally. SnSz-PVA （polyvinyl alcohol） film was successfully prepared and employed as a mode-locker for achieving a mode-locked Er-doped fiber laser with a pulse width of 623 fs at a pulse repetition rate of 29.33 MHz. The results prove that SnS2 nanosheets will have wide potential ultrafast photonic applications due to their suitable bandgap value and excellent nonlinear saturable absorption characteristics.
基金National Key Basic Research Program of China(2013CB922402)National Natural Science Foundation of China(NSFC)(61705174,11774277)+2 种基金Fundamental Research Funds for the Central Universities(JBX170511)Open Fund of IPOC(BUPT)(IPOC2016B009)111 Project(B17035)
文摘Stable 68 fs pulses with the average power of 1.5 W is directly generated from a multimode diode-pumped Kerr-lens mode-locked Yb:CYA laser by separating the gain medium and Kerr medium. The repetition rate is about 50 MHz, resulting in a single pulse energy of 30 n J and a peak power of 0.44 MW. To the best of our knowledge, this is the highest single pulse energy ever produced from a mode-locked Yb:CYA oscillator. Our experimental results show that Yb:CYA crystal is an excellent candidate for multiwatt, sub-100 fs pulse generation in diode-pumped all-solid-state lasers. It is believed that the output power can be scalable to multi-W while the pulse duration is maintained with this simple method.
基金sponsored by the National Natural Science Foundation of China(Grant Nos.61925502,61535005,and 61975107)the National Key R&D Program of China(Grant Nos.2017YFA0303700 and 2017YFA0700503).
文摘Ultrafast lasers generating high-repetition-rate ultrashort pulses through various mode-locking methods can benefit many important applications,including communications,materials processing,astronomical observation,etc.For decades,mode-locking based on dissipative four-wave-mixing(DFWM)has been fundamental in producing pulses with repetition rates on the order of gigahertz(GHz),where multiwavelength comb filters and long nonlinear components are elemental.Recently,this method has been improved using filter-driven DFWM,which exploits both the filtering and nonlinear features of silica microring resonators.However,the fabrication complexity and coupling loss between waveguides and fibers are problematic.We demonstrate a tens-to hundreds-of gigahertz-stable pulsed all-fiber laser based on a hybrid plasmonic microfiber knot resonator device.Unlike previously reported pulse generation mechanisms,the operation utilizes the nonlinear-polarization-rotation(NPR)effect introduced by the polarization-dependent feature of the device to increase intracavity power for boosting DFWM mode-locking,which we term NPRstimulated DFWM.The easily fabricated versatile device acts as a polarizer,comb filter,and nonlinear component simultaneously,thereby introducing an application of microfiber resonator devices in ultrafast and nonlinear photonics.We believe that our work underpins a significant improvement in achieving practical low-cost ultrafast light sources.
基金supported partially by the National Science Foundation of China (61475129,61177044,61107038,and 61275050)the Project for Undergraduates’ Innovation and Undertaking in Xiamen University (0630ZX11A1)
文摘In this paper,both nonlinear saturable absorption and two-photon absorption（TPA） of few-layer molybdenum diselenide（MoSe2） were observed at 1.56 μm wavelength and further applied to mode-locked ultrafast fiber laser for the first time to our knowledge.Few-layer MoSe2 nanosheets were prepared by liquid-phase exfoliation method and characterized by x ray diffractometer,Raman spectroscopy,and atomic force microscopy.The obtained fewlayer MoSe2 dispersion is further composited with a polymer material for convenient fabrication of MoSe2 thin films.Then,we investigated the nonlinear optical（NLO） absorption property of the few-layer MoSe2 film using a balanced twin-detector measurement technique.Both the saturable absorption and TPA effects of the few-layer MoSe2 film were found by increasing the input optical intensity.The saturable absorption shows a modulation depth of 0.63% and a low nonsaturable loss of 3.5%,corresponding to the relative modulation depth of 18%.The TPA effect occurred when the input optical intensity exceeds 260 MW∕cm2.Furthermore,we experimentally exploit the saturable absorption of few-layer MoSe2 film to mode lock an all-fiber erbium-doped fiber laser.Stable soliton mode locking at 1558 nm center wavelength is achieved with pulse duration of 1.45 ps.It was also observed that the TPA process suppresses the mode-locking operation in the case of higher optical intensity.Our results indicate that layered MoSe2,as another two-dimensional nanomaterial,can provide excellent NLO properties（e.g.,saturable absorption and TPA） for potential applications in ultrashort pulse generation and optical limiting.
基金supported by the National Major Scientific Instruments Development Project of China (Grant No. 2012YQ120047)the National Natural Science Foundation of China (Grant No. 61205130)
文摘We experimentally demonstrated a diode-pumped Kerr-lens mode-locked femtosecond laser with a Yb:CaYAlO4 crystal as the gain medium. Pulse duration as short as 33 fs was obtained directly from the oscillator at a repetition rate of 115 MHz. The central wavelength was at 1059 nm with a spectral bandwidth of 49 nm. These are, to the bestof our knowledge, the shortest pulses generated from a Yb:CaYAlO4 oscillator.
基金supported by the National Natural Science Foundation of China(Nos.61675130,91850203,and 11721091)the National Postdoctoral Program for Innovative Talents(No.BX20170149)。
文摘We demonstrated a femtosecond mode-locked Er:Zr F4-Ba F2-La F3-Al F3-Na F(Er:ZBLAN)fiber laser at 2.8μm based on the nonlinear polarization rotation technique.The laser generated an average output power of 317 m W with a repetition rate of 107 MHz and pulse duration as short as 131 fs.To the best of our knowledge,this is the shortest pulse generated directly from a mid-infrared mode-locked Er:ZBLAN fiber laser to date.Numerical simulation and experimental results confirm that reducing the gain fiber length is an effective way to shorten the mode-locked pulse duration in the Er:ZBLAN fiber laser.The work takes an important step towards sub-100-fs mid-infrared pulse generation from mode-locked Er:ZBLAN fiber lasers.
基金supported by the National Basic Research Program of China(Grant No.2011CB808101)the National Natural Science Foundation of China(NSFC)(Grant Nos.61078037,11127901,11134010,and 11204328)+3 种基金the NSFC (No. 61178007)the External Cooperation Program of Bureau of International Cooperation, Chinese Academy of Sciences (No. 181231KYSB20130007)the National 10000-Talent ProgramCAS 100-Talent Program for financial support
文摘A passively Q-swithched mode-locked （QML） Tm：LiLuF4 （LLF） laser with a MoS2 saturable absorber （SA） is demonstrated for the first time, to our best knowledge. For the Q-switching mode, the maximum average output power and Q-switched pulse energy are 583 mW and 41.5 μJ, respectively. When the absorbed power is greater than 7.4 W, the passively QML pulse is formed, corresponding to an 83.3-MHz frequency. The modulation depth in Q-switching envelopes is approximately 50%. Results prove that MoS2 is a promising SA for Q-switched and QML solid-state lasers.
基金Defense Advanced Research Projects Agency(DARPA)EPHI and DODOS contracts
文摘The mode-locked laser diode has emerged as a promising candidate as a signal source for photonic radar systems,wireless data transmission, and frequency comb spectroscopy. They have the advantages of small size, low cost,high reliability, and low power consumption, thanks to semiconductor technology. Mode-locked lasers based on silicon photonics advance these qualities by the use of highly advanced silicon manufacturing technology. This paper will begin by giving an overview of mode-locked laser diode literature, and then focus on mode-locked lasers on silicon. The dependence of mode-locked laser performance on design details is presented.
基金supported by the National Natural Science Foundation of China(Nos.61535009,11527808,61605142,and 61735007)the Tianjin Research Program of Application Foundation and Advanced Technology(No.17JCJQJC43500)
文摘We demonstrate an all polarization-maintaining(PM) fiber mode-locked laser seeded, hybrid fiber/solid-slab picosecond pulse laser system which outputs 40 μJ, 10 ps pulses at the central wavelength of 1064 nm. The beam quality factors M2 in the unstable and stable directions are 1.35 and 1.31, respectively. 15 μJ picosecond pulses at the central wavelength of 355 nm are generated through third harmonic generation(THG) by using two Li B3 O5(LBO) crystals, in order to get better processing efficiency on polycrystalline diamonds. The high pulse energy and beam quality of these ultraviolet(UV) picosecond pulses are confirmed by latter experiments of material processing on polycrystalline diamonds. This scheme which combines the advantages of the all PM fiber mode-locked laser and the solid-slab amplifier enables compact, robust and chirped pulse amplification-free amplification with high power picosecond pulses.
