A multiwavelength tunable ring-cavity erbium-doped fiber laser(EDFL)based on a Lyot filter was presented.For the proposed Lyot filter,a comb filter consisting of an EDF-polarization-maintaining fiber(EDF-PMF),a polari...A multiwavelength tunable ring-cavity erbium-doped fiber laser(EDFL)based on a Lyot filter was presented.For the proposed Lyot filter,a comb filter consisting of an EDF-polarization-maintaining fiber(EDF-PMF),a polarization controller(PC),and a circulator with four ports was used to suppress the mode competition.The light transmission direction was guaranteed by the circulator.For the proposed fiber laser,tunable single,dual,triple,quadruple,quintuple,sextuple,and septuple wavelengths were realized.A single-wavelength laser output with an optical signal-to-noise ratio(SNR)of up to30.56 dB was realized,and a tuning range of 1590.54 nm to 1599.54 nm was achieved by tuning the PC.The stability of the single,dual,triple,and quadruple-wavelength center power fluctuations was less than 0.05 dB,0.98 dB,5.07 dB,and7.71 dB respectively.When the laser was operated in the multiwavelength condition,the SNR was more than 20.97 dB.The proposed erbium-doped fiber laser is suitable for fiber-sensing system applications.展开更多
The dynamical behaviour of the erbium-doped fibre single-ring laser with an optical delay feedback is discussed. Simulation shows that as the delay rate increases, the lasing light displays period-doubling which leads...The dynamical behaviour of the erbium-doped fibre single-ring laser with an optical delay feedback is discussed. Simulation shows that as the delay rate increases, the lasing light displays period-doubling which leads to chaos and via reverse period-doubling route returns from chaos to periodic. At a particular delay rate the intermittently chaotic route to chaos is also observed. The identical synchronization based on chaos in this ring laser is demonstrated by numerical simulation.展开更多
This paper reports a systematic experimental investigation on the dynamics in the low-frequency region in an erbium-doped fibre-ring laser with loss modulation. A rich variety of bifurcation is analyzed through the bi...This paper reports a systematic experimental investigation on the dynamics in the low-frequency region in an erbium-doped fibre-ring laser with loss modulation. A rich variety of bifurcation is analyzed through the bifurcation diagram and structured with the concept of the winding numbers. The coexistence of multiple attractors and the crisis that appear in the saddle-node bifurcations, and an interesting structure of bifurcation which is similar to the bifurcations in high-frequency range, have been observed.展开更多
We present a stable linear-cavity single longitudinal mode (SLM) erbium-doped silica fiber laser. It consists of four fiber Bragg gratings (FBGs) directly written in a section of photosensitive erbium-doped fiber ...We present a stable linear-cavity single longitudinal mode (SLM) erbium-doped silica fiber laser. It consists of four fiber Bragg gratings (FBGs) directly written in a section of photosensitive erbium-doped fiber (EDF) to form an asymmetric three-cavity structure. The stable SLM operation at a wavelength of 1545.112 nm with a 3-dB bandwidth of 0.012 nm and an optical signal-to-noise ratio (OSNR) of about 60 dB is verified experimentally. Under laboratory conditions, the performance of a power fluctuation of less than 0.05 dB observed from the power meter for 6 h and a wavelength variation of less than 0.01 nm obtained from the optical spectrum analyzer (OSA) for about 1.5 h are demonstrated. The gain fiber length is no longer limited to only several centimeters for SLM operation because of the excellent mode-selecting ability of the asymmetric three-cavity structure. The proposed scheme provides a simple and cost-effective approach to realizing a stable SLM fiber laser.展开更多
A mode-locked erbium doped fiber laser(EDFL) is demonstrated using the vanadium oxide(V2O5) material as a saturable absorber(SA). The V2O5 based SA is hosted into poly ethylene oxide film and attached on fiber f...A mode-locked erbium doped fiber laser(EDFL) is demonstrated using the vanadium oxide(V2O5) material as a saturable absorber(SA). The V2O5 based SA is hosted into poly ethylene oxide film and attached on fiber ferule in the laser cavity. It shows 7% modulation depth with 71 MW/cm2 saturation intensity. By incorporating the SA inside the EDFL cavity with managed intra-cavity dispersion, ultrashort soliton pulses are successfully generated with a full width at half maximum of 3.14 ps. The laser operated at central wavelength of 1559.25 nm and repetition frequency of 1 MHz.展开更多
In this paper,the chaotic behaviors in an erbium-doped fiber(EDF) single-ring laser(EDFSRL) are investigated experimentally by using the loss modulation method.An electro-optic modulator(EOM) made of LiNbO 3 cry...In this paper,the chaotic behaviors in an erbium-doped fiber(EDF) single-ring laser(EDFSRL) are investigated experimentally by using the loss modulation method.An electro-optic modulator(EOM) made of LiNbO 3 crystal is added to the system.Thus,by changing the modulation voltage and the modulation frequency of the EOM,the freedom of the EDFSRL system is increased.The chaotic characteristics of the system are studied by observing the time series and the power spectra.The experimental results indicate that the erbium-doped fiber single-ring laser system can enter into chaos states through period-doubling bifurcation and intermittency routes.展开更多
The transition state between the continuous wave region and the mode-locked region in a passively mode-locked erbium-doped fibre ring laser has been experimentally observed by utilizing the nonlinear polarization rota...The transition state between the continuous wave region and the mode-locked region in a passively mode-locked erbium-doped fibre ring laser has been experimentally observed by utilizing the nonlinear polarization rotation technique. When the pump power reaches the mode-locked threshold, the metastable pulse train with a tunable repetition rate is obtained in the transition from the continuous wave state to the passive mode-locked state via proper adjustment of the polarization controller. A simpie model has been established to explain the experimental observation.展开更多
A stable Q-switched erbium doped fiber laser emitting at 1558 nm is demonstrated using a cadmium selenide(CdSe) material coated onto a side-polished D-shape fiber as the saturable absorber(SA). By elevating the in...A stable Q-switched erbium doped fiber laser emitting at 1558 nm is demonstrated using a cadmium selenide(CdSe) material coated onto a side-polished D-shape fiber as the saturable absorber(SA). By elevating the input pump power from the threshold of 91 mW to the maximum available power of 136 mW, a pulse train with a maximum repetition rate of 57.44 kHz, minimum pulse width of 3.76 us, maximum average output power of7.99 mW, maximum pulse energy of 0.1391 uJ, and maximum peak power of 36.99 mW are obtained. The signalto-noise ratio of the spectrum is measured to be around 75 dB. This CdSe based SA is simple, robust, and reliable,and thus suitable for making a portable pulse laser source.展开更多
We propose and demonstrate a Q-switched erbium-doped fiber laser (EDFL) using an erbium-doped zirconia-alumina silica glass-based fiber (Zr-EDF) as a saturable absorber. As a 16-cm-long Zr-EDF is incorporated into...We propose and demonstrate a Q-switched erbium-doped fiber laser (EDFL) using an erbium-doped zirconia-alumina silica glass-based fiber (Zr-EDF) as a saturable absorber. As a 16-cm-long Zr-EDF is incorporated into a ring EDFL cavity, a stable Q-switching pulse train operating at 1565?nm wavelength is successfully obtained. The repetition rate is tunable from 33.97?kHz to 71.23?kHz by increasing the pump power from the threshold of 26?mW to the maximum of 74?mW. The highest pulse energy of 26.67?nJ is obtained at the maximum pump power.展开更多
We demonstrate an ultrafast fiber laser based on transition metal dichalcogenide materials which are tungsten disulfide (WS<sub>2</sub>) and molybdenum disulfide (MoS<sub>2</sub>) as saturable ...We demonstrate an ultrafast fiber laser based on transition metal dichalcogenide materials which are tungsten disulfide (WS<sub>2</sub>) and molybdenum disulfide (MoS<sub>2</sub>) as saturable absorber (SA). These materials are fabricated via a simple drop-casting method. By employing WS<sub>2</sub>, we obtain a stable harmonic mode-locking at the threshold pump power of 184 mW, and the generated soliton pulse has 3.48 MHz of repetition rate. At the maximum pump power of 250 mW, we also obtain a small value of pulse duration, 2.43 ps with signal-to-noise ratio (SNR) of 57 dB. For MoS<sub>2</sub> SA, the pulse is generated at 105 mW pump power with repetition rate of 1.16 MHz. However, the pulse duration cannot be detected by the autocorrelator device as the pulse duration recorded is 468 ns, with the SNR value of 35 dB.展开更多
We demonstrate a stable Q-switched mode-locked erbium-doped fiber laser (EDFL) operating in dark regime based on the nonlinear polarization rotation technique. The EDFL produces a pulse train where the Q-switching e...We demonstrate a stable Q-switched mode-locked erbium-doped fiber laser (EDFL) operating in dark regime based on the nonlinear polarization rotation technique. The EDFL produces a pulse train where the Q-switching envelope is formed by multiple dark pulses. The repetition rate of the Q-switched envelope can be increased from 0.96kHz to 3.26kHz, whereas the pulse width reduces from 211 #s to 86#s. The highest pulse of 479nJ is obtained at the pump power of 55 mW. It is also observed that the dark pulses inside the Q-switching envelope consist of two parts: square and trailing dark pulses. The shortest pulse width of the dark square pulse is obtained at 40.5μs when the pump power is fixed at 145mW. The repetition rate of trailing dark pulses can be increased from 27.62kHz to 50kHz as the pump power increases from 55mW to 145mW.展开更多
We demonstrate a Q-switched erbium-doped fiber laser (EDFL) using a newly developed zinc oxide- (ZnO) based saturable absorber (SA). The SA is fabricated by embedding a prepared ZnO powder into a poly(vinyl alc...We demonstrate a Q-switched erbium-doped fiber laser (EDFL) using a newly developed zinc oxide- (ZnO) based saturable absorber (SA). The SA is fabricated by embedding a prepared ZnO powder into a poly(vinyl alcohol) film. A small piece of the film is then sandwiched between two fiber ferrules and is incorporated in an EDFL cavity for generating a stable Q-switching pulse train. The EDFL operates at 1560.4nm with a pump power threshold of 11.8mW, a pulse repetition rate tunable from 22.79 to 61.43kHz, and the smallest pulse width of 7.00 μs. The Q-switching pulse shows no spectral modulation with a peak-to-pedestal ratio of 62 dB indicating the high stability of the laser. These results show that the ZnO powder has a great potential to be used for pulsed laser applications.展开更多
A harmonic dark pulse generation in an erbium-doped fiber laser is demonstrated based on a figure-of-eight configuration. It is found that the harmonic dark pulse can be shifted from the fundamental to the 5th order h...A harmonic dark pulse generation in an erbium-doped fiber laser is demonstrated based on a figure-of-eight configuration. It is found that the harmonic dark pulse can be shifted from the fundamental to the 5th order harmonic by increasing the pump power with an appropriate polarization controller orientation. The fundamental repetition rate of 2O kHz is obtained at the pump power of 29 m W. The highest pulse energy of 42.6 n3 is obtained at the fundamental repetition rate. The operating frequency of the dark pulse trains shifts to 2nd, 3rd, 4th and 5th harmonic as the pump powers are increased to 34mW, 50mW, 59mW and 137mW, respectively.展开更多
We demonstrate the generation of dark and bright solitons with our homemade zirconia-based erbium-doped fiber and graphene oxide(GO) saturable absorber in anomalous dispersion region.The GO is fabricated using an ab...We demonstrate the generation of dark and bright solitons with our homemade zirconia-based erbium-doped fiber and graphene oxide(GO) saturable absorber in anomalous dispersion region.The GO is fabricated using an abridged Hummer's method,which is combined with polyethylene oxide to produce a composite film.The film is sandwiched between two optical ferrules and embedded in the laser cavity to enhance its birefringence and nonlinearity.The self-starting bright soliton is easily generated at pump power of 78 mW with the whole length cavity of 14.7 m.The laser produces the bright pulse train with repetition rate,pulse width,pulse energy and central wavelength being 13.9 MHz,0.6 ps,2.74 p J and 1577.46 nm,respectively.Then,by adding the 10 m of single mode fiber into the laser cavity,dark soliton pulse is produced.For the formation of dark pulse train,the measured repetition rate,pulse width,pulse energy and central wavelength are 8.3 MHz,20 ns and 4.98 p J and1596.82 nm,respectively.Both pulses operate in the anomalous region.展开更多
BACKGROUND The goal of periodontal disease treatment is to completely remove bacteria and promote wound healing.The erbium-doped yttrium aluminum garnet(Er:YAG)laser is commonly used to treat periodontal disease.Advan...BACKGROUND The goal of periodontal disease treatment is to completely remove bacteria and promote wound healing.The erbium-doped yttrium aluminum garnet(Er:YAG)laser is commonly used to treat periodontal disease.Advanced platelet-rich fibrin+(A-PRF+)secrets growth factors that accelerates soft-and hard-tissue regeneration and wound healing.Herein I present 2 cases of patients with oral diseases treated with a combination of Er:YAG laser and A-PRF+.CASE SUMMARY Case 1 was a female with pocket depth bone loss over 8 mm and infection of tooth 31 and 41,and severe advanced periodontitis with grade III mobility.Case 2 was a male with tooth 22 root end apical swelling and infection and alveolar bony defects.Clinical outcomes were recorded at 6 and 36 mo.In case 1,the Er:YAG laser was used to perform open flap debridement(100 mJ/pulse,15 Hz)and remove calculus and granulation tissue(50 mJ/pulse,30 Hz).In case 2 the laser was used to create a semilunar full thickness flap incision(80 mJ/pulse,20 Hz)and eliminate the pathogen(100 mJ/pulse,15 Hz).In both patients,A-PRF+mixed with bone was used to fill bone defects,and A-PRF+autologous membranes were used to cover tension-free primary flaps.There was no recurrent infection at 36 mo,and tissue regeneration and would healing occurred.CONCLUSION Debridement with an Er:YAG laser followed by treatment with A-PRF+is effective for the treatment periodontal diseases with bone defects.展开更多
GeSe nanosheets were prepared by ultrasonic-assisted liquid<span><span><span style="font-family:;" "=""> </span></span></span><span><span><sp...GeSe nanosheets were prepared by ultrasonic-assisted liquid<span><span><span style="font-family:;" "=""> </span></span></span><span><span><span><span style="font-family:Verdana;">phase exfoliation (LPE), and the nonlinear saturated absorption performance was experimentally studied. The modulation depth and saturation intensity of the prepared GeSe saturable absorber (SA) were 15% and 1.44 MW/cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, respectively. Us</span><span style="font-family:Verdana;">ing the saturated absorption characteristics of GeSe SA, a passively Q-switched </span><span style="font-family:Verdana;">erbium-doped fiber laser was systematically demonstrated. As the pump</span><span style="font-family:Verdana;"> power increases, the pulse repetition frequency increases from 22.8 kHz to 77.59 </span><span style="font-family:Verdana;">kHz. The shortest pulse duration is 1.51 μs, and the corresponding pulse</span><span style="font-family:Verdana;"> energy is 46.14 nJ. Experimental results show that GeSe nanosheets can be used as high-efficiency SA in fiber lasers. Our results will provide a useful reference for demonstrating pulsed fiber lasers based on GeSe equipment.</span></span></span></span>展开更多
<span style="font-family:Verdana;">T</span><span style="font-family:Verdana;font-size:12px;">he T</span><span style="font-family:Verdana;font-size:12px;">i&l...<span style="font-family:Verdana;">T</span><span style="font-family:Verdana;font-size:12px;">he T</span><span style="font-family:Verdana;font-size:12px;">i</span><span style="font-family:Verdana;font-size:12px;">Se</span><sub><span style="font-family:Verdana;font-size:12px;">2</span></sub><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">nanosheets</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">were</span><span style="font-family:Verdana;font-size:12px;"> prepared by means of ultrasound-assisted liquid </span><span style="font-family:Verdana;font-size:12px;">phase exfoliation (LPE)</span><span style="font-family:Verdana;font-size:12px;"> and the </span><span style="font-family:Verdana;font-size:12px;">nonlinear </span><span style="font-family:Verdana;font-size:12px;">saturable absorption</span><span style="font-family:Verdana;font-size:12px;"> properties</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">were experimentally</span><span style="font-family:Verdana;font-size:12px;"> investigated. The modulation depth, saturation intensity and nonsaturable absorbance</span><span style="font-family:Verdana;font-size:12px;"> of the prepared </span><span style="font-family:Verdana;font-size:12px;">1T-TiSe</span><sub><span style="font-family:Verdana;font-size:12px;">2</span></sub><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">SA </span><span style="font-family:Verdana;font-size:12px;">were</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">1</span><span style="font-family:Verdana;font-size:12px;">5.7</span><span style="font-family:Verdana;font-size:12px;">%,</span><span style="font-family:Verdana;font-size:12px;"> 1.28 M</span><span style="font-family:Verdana;font-size:12px;">W/cm</span><sup><span style="font-family:Verdana;font-size:12px;vertical-align:super;">2</span></sup><span style="font-family:Verdana;font-size:12px;"> and 8.</span><span style="font-family:Verdana;font-size:12px;">2</span><span style="font-family:Verdana;font-size:12px;">%, </span><span style="font-family:Verdana;font-size:12px;">respectively</span><span style="font-family:Verdana;font-size:12px;">. Taking advantage of the saturable absorption properties of </span><span style="font-family:Verdana;font-size:12px;">T</span><span style="font-family:Verdana;font-size:12px;">i</span><span style="font-family:Verdana;font-size:12px;">Se</span><sub><span style="font-family:Verdana;font-size:12px;">2</span></sub><span style="font-family:Verdana;font-size:12px;">-based SA, a passively Q-switched erbium-doped fiber (EDF) laser was</span><span style="font-family:Verdana;font-size:12px;"> systematically demonstrated</span><span style="font-family:Verdana;font-size:12px;">. The pulse repetition rates varied from 24.50 kHz up to 73.79 kHz with the increasing pump power. The obtained shortest pulse width was 1.31 </span><span style="font-family:Verdana;font-size:12px;">μ</span><span style="font-family:Verdana;font-size:12px;">s with pulse energy of 79.28 nJ. The </span><span style="font-family:Verdana;font-size:12px;">system presented merits of low-cost SA preparation, system compactness,</span><span style="font-family:Verdana;font-size:12px;"> superb stability and high competition.</span>展开更多
We demonstrate a stable narrow linewidth single-frequency erbium-doped fiber laser(EDFL)operating at 1.6μm.A Fabry–Perot fiber Bragg grating and two cascaded subrings are incorporated in the main ring cavity to achi...We demonstrate a stable narrow linewidth single-frequency erbium-doped fiber laser(EDFL)operating at 1.6μm.A Fabry–Perot fiber Bragg grating and two cascaded subrings are incorporated in the main ring cavity to achieve singlefrequency operation.The experimentally measured optical signal-to-noise ratio is greater than 73 dB.Furthermore,the linewidth of the EDFL is measured to be about 480 Hz by the self-built short-delayed self-heterodyne interferometry device.The laser shows superior stability,with no mode-hopping during the 60-min observation period.The proposed EDFL provides a new experimental idea for realizing a single-frequency fiber laser in the L-band.展开更多
MXenes,drawn from MAX phases,are special two-dimensional substances with numerous advantages in nonlinear optics,specifically in giant and ultrashort pulsed-laser applications.Ti_(3)C_(2)T_(x)and Ti_(2)CT_(x)nanosheet...MXenes,drawn from MAX phases,are special two-dimensional substances with numerous advantages in nonlinear optics,specifically in giant and ultrashort pulsed-laser applications.Ti_(3)C_(2)T_(x)and Ti_(2)CT_(x)nanosheets however rapidly deteriorate under ambient conditions,limiting their applications.This paper demonstrates how excellent modulation depth of one of the MAX phase compounds vanadium zinc carbide(V_2ZnC)makes it a brilliant saturable absorber(SA)in passively Q-switched all-fiber pulsed lasers,integrated such that a 16.73-μm V_(2)ZnC-polyvinyl alcohol(PVA)thin film acts as SA in the laser.Saturable and non-saturable absorptions were found to be 13.2%and 10.47%,while saturation optical intensity and modulation depth were 6.25 k W/cm^(2)and 12.43%,respectively,illustrating the optical nonlinearity.The superiority of MAX-PVA,fabricated in four distinct ratios,was demonstrated by the fact that it self-starts a giant pulsed laser at pump power as low as 22.5 mW and firmly accomplished 120.6 kHz repetition rate with a pulse width of 2.08μs.It is a fine SA for the use of pulsed-laser production using all-fiber laser due to fabrication simplicity and great optical,thermophysical,and mechanical qualities.展开更多
基金Beijing Great Wall Scholars Program(Grant No.CIT&TCD20190323)Beijing Youth Talent Support Program(Grant No.Z2019042)the National Natural Science Foundation of China(Grant No.61875237).
文摘A multiwavelength tunable ring-cavity erbium-doped fiber laser(EDFL)based on a Lyot filter was presented.For the proposed Lyot filter,a comb filter consisting of an EDF-polarization-maintaining fiber(EDF-PMF),a polarization controller(PC),and a circulator with four ports was used to suppress the mode competition.The light transmission direction was guaranteed by the circulator.For the proposed fiber laser,tunable single,dual,triple,quadruple,quintuple,sextuple,and septuple wavelengths were realized.A single-wavelength laser output with an optical signal-to-noise ratio(SNR)of up to30.56 dB was realized,and a tuning range of 1590.54 nm to 1599.54 nm was achieved by tuning the PC.The stability of the single,dual,triple,and quadruple-wavelength center power fluctuations was less than 0.05 dB,0.98 dB,5.07 dB,and7.71 dB respectively.When the laser was operated in the multiwavelength condition,the SNR was more than 20.97 dB.The proposed erbium-doped fiber laser is suitable for fiber-sensing system applications.
基金Project supported by the National Natural Science Foundation of China (Grant No 60372061).
文摘The dynamical behaviour of the erbium-doped fibre single-ring laser with an optical delay feedback is discussed. Simulation shows that as the delay rate increases, the lasing light displays period-doubling which leads to chaos and via reverse period-doubling route returns from chaos to periodic. At a particular delay rate the intermittently chaotic route to chaos is also observed. The identical synchronization based on chaos in this ring laser is demonstrated by numerical simulation.
文摘This paper reports a systematic experimental investigation on the dynamics in the low-frequency region in an erbium-doped fibre-ring laser with loss modulation. A rich variety of bifurcation is analyzed through the bifurcation diagram and structured with the concept of the winding numbers. The coexistence of multiple attractors and the crisis that appear in the saddle-node bifurcations, and an interesting structure of bifurcation which is similar to the bifurcations in high-frequency range, have been observed.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61077069 and 61107094)the Innovation Foundation for Excellent Doctoral Candidates of Beijing Jiaotong University, China (Grant No. 2011YJS202)
文摘We present a stable linear-cavity single longitudinal mode (SLM) erbium-doped silica fiber laser. It consists of four fiber Bragg gratings (FBGs) directly written in a section of photosensitive erbium-doped fiber (EDF) to form an asymmetric three-cavity structure. The stable SLM operation at a wavelength of 1545.112 nm with a 3-dB bandwidth of 0.012 nm and an optical signal-to-noise ratio (OSNR) of about 60 dB is verified experimentally. Under laboratory conditions, the performance of a power fluctuation of less than 0.05 dB observed from the power meter for 6 h and a wavelength variation of less than 0.01 nm obtained from the optical spectrum analyzer (OSA) for about 1.5 h are demonstrated. The gain fiber length is no longer limited to only several centimeters for SLM operation because of the excellent mode-selecting ability of the asymmetric three-cavity structure. The proposed scheme provides a simple and cost-effective approach to realizing a stable SLM fiber laser.
文摘A mode-locked erbium doped fiber laser(EDFL) is demonstrated using the vanadium oxide(V2O5) material as a saturable absorber(SA). The V2O5 based SA is hosted into poly ethylene oxide film and attached on fiber ferule in the laser cavity. It shows 7% modulation depth with 71 MW/cm2 saturation intensity. By incorporating the SA inside the EDFL cavity with managed intra-cavity dispersion, ultrashort soliton pulses are successfully generated with a full width at half maximum of 3.14 ps. The laser operated at central wavelength of 1559.25 nm and repetition frequency of 1 MHz.
基金Project supported by the Science and Technology Development Program of Jilin Province,China (Grant No. 20090309)
文摘In this paper,the chaotic behaviors in an erbium-doped fiber(EDF) single-ring laser(EDFSRL) are investigated experimentally by using the loss modulation method.An electro-optic modulator(EOM) made of LiNbO 3 crystal is added to the system.Thus,by changing the modulation voltage and the modulation frequency of the EOM,the freedom of the EDFSRL system is increased.The chaotic characteristics of the system are studied by observing the time series and the power spectra.The experimental results indicate that the erbium-doped fiber single-ring laser system can enter into chaos states through period-doubling bifurcation and intermittency routes.
基金Project supported by the National Natural Science Foundation of China(Grant No.11074078)the Specialized Research Fund for the Doctoral Program of Higher Education,China(Grant No.20094407110002)+1 种基金the Key Program for Scientific and Technological Innovations of Higher Education Institutes in Guangdong Province,China(Grant No.cxzd1011)the Foundation for Distinguished Young Talents in Higher Education of Guangdong,China(Grant No.C10183)
文摘The transition state between the continuous wave region and the mode-locked region in a passively mode-locked erbium-doped fibre ring laser has been experimentally observed by utilizing the nonlinear polarization rotation technique. When the pump power reaches the mode-locked threshold, the metastable pulse train with a tunable repetition rate is obtained in the transition from the continuous wave state to the passive mode-locked state via proper adjustment of the polarization controller. A simpie model has been established to explain the experimental observation.
文摘A stable Q-switched erbium doped fiber laser emitting at 1558 nm is demonstrated using a cadmium selenide(CdSe) material coated onto a side-polished D-shape fiber as the saturable absorber(SA). By elevating the input pump power from the threshold of 91 mW to the maximum available power of 136 mW, a pulse train with a maximum repetition rate of 57.44 kHz, minimum pulse width of 3.76 us, maximum average output power of7.99 mW, maximum pulse energy of 0.1391 uJ, and maximum peak power of 36.99 mW are obtained. The signalto-noise ratio of the spectrum is measured to be around 75 dB. This CdSe based SA is simple, robust, and reliable,and thus suitable for making a portable pulse laser source.
基金Supported by the Postgraduate Research of Malaysia under Grant No PG098-2014Bthe CSIR of Government of India
文摘We propose and demonstrate a Q-switched erbium-doped fiber laser (EDFL) using an erbium-doped zirconia-alumina silica glass-based fiber (Zr-EDF) as a saturable absorber. As a 16-cm-long Zr-EDF is incorporated into a ring EDFL cavity, a stable Q-switching pulse train operating at 1565?nm wavelength is successfully obtained. The repetition rate is tunable from 33.97?kHz to 71.23?kHz by increasing the pump power from the threshold of 26?mW to the maximum of 74?mW. The highest pulse energy of 26.67?nJ is obtained at the maximum pump power.
基金Supported by the University of Malaya under Grant No PG173-2015B
文摘We demonstrate an ultrafast fiber laser based on transition metal dichalcogenide materials which are tungsten disulfide (WS<sub>2</sub>) and molybdenum disulfide (MoS<sub>2</sub>) as saturable absorber (SA). These materials are fabricated via a simple drop-casting method. By employing WS<sub>2</sub>, we obtain a stable harmonic mode-locking at the threshold pump power of 184 mW, and the generated soliton pulse has 3.48 MHz of repetition rate. At the maximum pump power of 250 mW, we also obtain a small value of pulse duration, 2.43 ps with signal-to-noise ratio (SNR) of 57 dB. For MoS<sub>2</sub> SA, the pulse is generated at 105 mW pump power with repetition rate of 1.16 MHz. However, the pulse duration cannot be detected by the autocorrelator device as the pulse duration recorded is 468 ns, with the SNR value of 35 dB.
基金Supported by the Fund from University of Malaya under Grant No RU007/2015LRGS(2015)/NGOD/UM/KPTMOSTI under Grant No SF014-2014
文摘We demonstrate a stable Q-switched mode-locked erbium-doped fiber laser (EDFL) operating in dark regime based on the nonlinear polarization rotation technique. The EDFL produces a pulse train where the Q-switching envelope is formed by multiple dark pulses. The repetition rate of the Q-switched envelope can be increased from 0.96kHz to 3.26kHz, whereas the pulse width reduces from 211 #s to 86#s. The highest pulse of 479nJ is obtained at the pump power of 55 mW. It is also observed that the dark pulses inside the Q-switching envelope consist of two parts: square and trailing dark pulses. The shortest pulse width of the dark square pulse is obtained at 40.5μs when the pump power is fixed at 145mW. The repetition rate of trailing dark pulses can be increased from 27.62kHz to 50kHz as the pump power increases from 55mW to 145mW.
基金Supported by the University of Malaya under Grant No PG173-2015B
文摘We demonstrate a Q-switched erbium-doped fiber laser (EDFL) using a newly developed zinc oxide- (ZnO) based saturable absorber (SA). The SA is fabricated by embedding a prepared ZnO powder into a poly(vinyl alcohol) film. A small piece of the film is then sandwiched between two fiber ferrules and is incorporated in an EDFL cavity for generating a stable Q-switching pulse train. The EDFL operates at 1560.4nm with a pump power threshold of 11.8mW, a pulse repetition rate tunable from 22.79 to 61.43kHz, and the smallest pulse width of 7.00 μs. The Q-switching pulse shows no spectral modulation with a peak-to-pedestal ratio of 62 dB indicating the high stability of the laser. These results show that the ZnO powder has a great potential to be used for pulsed laser applications.
文摘A harmonic dark pulse generation in an erbium-doped fiber laser is demonstrated based on a figure-of-eight configuration. It is found that the harmonic dark pulse can be shifted from the fundamental to the 5th order harmonic by increasing the pump power with an appropriate polarization controller orientation. The fundamental repetition rate of 2O kHz is obtained at the pump power of 29 m W. The highest pulse energy of 42.6 n3 is obtained at the fundamental repetition rate. The operating frequency of the dark pulse trains shifts to 2nd, 3rd, 4th and 5th harmonic as the pump powers are increased to 34mW, 50mW, 59mW and 137mW, respectively.
文摘We demonstrate the generation of dark and bright solitons with our homemade zirconia-based erbium-doped fiber and graphene oxide(GO) saturable absorber in anomalous dispersion region.The GO is fabricated using an abridged Hummer's method,which is combined with polyethylene oxide to produce a composite film.The film is sandwiched between two optical ferrules and embedded in the laser cavity to enhance its birefringence and nonlinearity.The self-starting bright soliton is easily generated at pump power of 78 mW with the whole length cavity of 14.7 m.The laser produces the bright pulse train with repetition rate,pulse width,pulse energy and central wavelength being 13.9 MHz,0.6 ps,2.74 p J and 1577.46 nm,respectively.Then,by adding the 10 m of single mode fiber into the laser cavity,dark soliton pulse is produced.For the formation of dark pulse train,the measured repetition rate,pulse width,pulse energy and central wavelength are 8.3 MHz,20 ns and 4.98 p J and1596.82 nm,respectively.Both pulses operate in the anomalous region.
文摘BACKGROUND The goal of periodontal disease treatment is to completely remove bacteria and promote wound healing.The erbium-doped yttrium aluminum garnet(Er:YAG)laser is commonly used to treat periodontal disease.Advanced platelet-rich fibrin+(A-PRF+)secrets growth factors that accelerates soft-and hard-tissue regeneration and wound healing.Herein I present 2 cases of patients with oral diseases treated with a combination of Er:YAG laser and A-PRF+.CASE SUMMARY Case 1 was a female with pocket depth bone loss over 8 mm and infection of tooth 31 and 41,and severe advanced periodontitis with grade III mobility.Case 2 was a male with tooth 22 root end apical swelling and infection and alveolar bony defects.Clinical outcomes were recorded at 6 and 36 mo.In case 1,the Er:YAG laser was used to perform open flap debridement(100 mJ/pulse,15 Hz)and remove calculus and granulation tissue(50 mJ/pulse,30 Hz).In case 2 the laser was used to create a semilunar full thickness flap incision(80 mJ/pulse,20 Hz)and eliminate the pathogen(100 mJ/pulse,15 Hz).In both patients,A-PRF+mixed with bone was used to fill bone defects,and A-PRF+autologous membranes were used to cover tension-free primary flaps.There was no recurrent infection at 36 mo,and tissue regeneration and would healing occurred.CONCLUSION Debridement with an Er:YAG laser followed by treatment with A-PRF+is effective for the treatment periodontal diseases with bone defects.
文摘GeSe nanosheets were prepared by ultrasonic-assisted liquid<span><span><span style="font-family:;" "=""> </span></span></span><span><span><span><span style="font-family:Verdana;">phase exfoliation (LPE), and the nonlinear saturated absorption performance was experimentally studied. The modulation depth and saturation intensity of the prepared GeSe saturable absorber (SA) were 15% and 1.44 MW/cm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">, respectively. Us</span><span style="font-family:Verdana;">ing the saturated absorption characteristics of GeSe SA, a passively Q-switched </span><span style="font-family:Verdana;">erbium-doped fiber laser was systematically demonstrated. As the pump</span><span style="font-family:Verdana;"> power increases, the pulse repetition frequency increases from 22.8 kHz to 77.59 </span><span style="font-family:Verdana;">kHz. The shortest pulse duration is 1.51 μs, and the corresponding pulse</span><span style="font-family:Verdana;"> energy is 46.14 nJ. Experimental results show that GeSe nanosheets can be used as high-efficiency SA in fiber lasers. Our results will provide a useful reference for demonstrating pulsed fiber lasers based on GeSe equipment.</span></span></span></span>
文摘<span style="font-family:Verdana;">T</span><span style="font-family:Verdana;font-size:12px;">he T</span><span style="font-family:Verdana;font-size:12px;">i</span><span style="font-family:Verdana;font-size:12px;">Se</span><sub><span style="font-family:Verdana;font-size:12px;">2</span></sub><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">nanosheets</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">were</span><span style="font-family:Verdana;font-size:12px;"> prepared by means of ultrasound-assisted liquid </span><span style="font-family:Verdana;font-size:12px;">phase exfoliation (LPE)</span><span style="font-family:Verdana;font-size:12px;"> and the </span><span style="font-family:Verdana;font-size:12px;">nonlinear </span><span style="font-family:Verdana;font-size:12px;">saturable absorption</span><span style="font-family:Verdana;font-size:12px;"> properties</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">were experimentally</span><span style="font-family:Verdana;font-size:12px;"> investigated. The modulation depth, saturation intensity and nonsaturable absorbance</span><span style="font-family:Verdana;font-size:12px;"> of the prepared </span><span style="font-family:Verdana;font-size:12px;">1T-TiSe</span><sub><span style="font-family:Verdana;font-size:12px;">2</span></sub><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">SA </span><span style="font-family:Verdana;font-size:12px;">were</span><span style="font-family:Verdana;font-size:12px;"> </span><span style="font-family:Verdana;font-size:12px;">1</span><span style="font-family:Verdana;font-size:12px;">5.7</span><span style="font-family:Verdana;font-size:12px;">%,</span><span style="font-family:Verdana;font-size:12px;"> 1.28 M</span><span style="font-family:Verdana;font-size:12px;">W/cm</span><sup><span style="font-family:Verdana;font-size:12px;vertical-align:super;">2</span></sup><span style="font-family:Verdana;font-size:12px;"> and 8.</span><span style="font-family:Verdana;font-size:12px;">2</span><span style="font-family:Verdana;font-size:12px;">%, </span><span style="font-family:Verdana;font-size:12px;">respectively</span><span style="font-family:Verdana;font-size:12px;">. Taking advantage of the saturable absorption properties of </span><span style="font-family:Verdana;font-size:12px;">T</span><span style="font-family:Verdana;font-size:12px;">i</span><span style="font-family:Verdana;font-size:12px;">Se</span><sub><span style="font-family:Verdana;font-size:12px;">2</span></sub><span style="font-family:Verdana;font-size:12px;">-based SA, a passively Q-switched erbium-doped fiber (EDF) laser was</span><span style="font-family:Verdana;font-size:12px;"> systematically demonstrated</span><span style="font-family:Verdana;font-size:12px;">. The pulse repetition rates varied from 24.50 kHz up to 73.79 kHz with the increasing pump power. The obtained shortest pulse width was 1.31 </span><span style="font-family:Verdana;font-size:12px;">μ</span><span style="font-family:Verdana;font-size:12px;">s with pulse energy of 79.28 nJ. The </span><span style="font-family:Verdana;font-size:12px;">system presented merits of low-cost SA preparation, system compactness,</span><span style="font-family:Verdana;font-size:12px;"> superb stability and high competition.</span>
基金supported by the Shaanxi Key Science and Technology Innovation Team Project(No.2023-CX-TD-06)。
文摘We demonstrate a stable narrow linewidth single-frequency erbium-doped fiber laser(EDFL)operating at 1.6μm.A Fabry–Perot fiber Bragg grating and two cascaded subrings are incorporated in the main ring cavity to achieve singlefrequency operation.The experimentally measured optical signal-to-noise ratio is greater than 73 dB.Furthermore,the linewidth of the EDFL is measured to be about 480 Hz by the self-built short-delayed self-heterodyne interferometry device.The laser shows superior stability,with no mode-hopping during the 60-min observation period.The proposed EDFL provides a new experimental idea for realizing a single-frequency fiber laser in the L-band.
基金supported by the Ministry of Higher under Fundamental Research Grant Scheme(No.FRGS/1/2020/TK0/UTM/02/46)Nippon Sheet Glass Grant(No.R.K130000.7343.4B818)。
文摘MXenes,drawn from MAX phases,are special two-dimensional substances with numerous advantages in nonlinear optics,specifically in giant and ultrashort pulsed-laser applications.Ti_(3)C_(2)T_(x)and Ti_(2)CT_(x)nanosheets however rapidly deteriorate under ambient conditions,limiting their applications.This paper demonstrates how excellent modulation depth of one of the MAX phase compounds vanadium zinc carbide(V_2ZnC)makes it a brilliant saturable absorber(SA)in passively Q-switched all-fiber pulsed lasers,integrated such that a 16.73-μm V_(2)ZnC-polyvinyl alcohol(PVA)thin film acts as SA in the laser.Saturable and non-saturable absorptions were found to be 13.2%and 10.47%,while saturation optical intensity and modulation depth were 6.25 k W/cm^(2)and 12.43%,respectively,illustrating the optical nonlinearity.The superiority of MAX-PVA,fabricated in four distinct ratios,was demonstrated by the fact that it self-starts a giant pulsed laser at pump power as low as 22.5 mW and firmly accomplished 120.6 kHz repetition rate with a pulse width of 2.08μs.It is a fine SA for the use of pulsed-laser production using all-fiber laser due to fabrication simplicity and great optical,thermophysical,and mechanical qualities.