A master-slave configuration used to control the nonlinear behaviors arising in a vertical cavity surface emitting laser (VCSEL) with strong external optical feedback is established. In terms of bifurcation diagram, t...A master-slave configuration used to control the nonlinear behaviors arising in a vertical cavity surface emitting laser (VCSEL) with strong external optical feedback is established. In terms of bifurcation diagram, time and frequency domain, the influence of the continuous optical injection from the master VCSEL on the nonlinear characteristics of the slave is investigated theoretically. For relatively weak injection, the slave still keeps its intrinsic nonlinear state. With increasing the injection strength, these nonlinear behaviors evolve to periodic fluctuation, and at last are replaced by the steady-state (e.g. the critical injection parameter for steady-state is 1.2 when external cavity's reflectivity and length are 4% and 4 cm, respectively). During this evolution the bifurcation-contraction phenomena are also observed.展开更多
The optical chaotic communication system using open-loop fiber transmission is studied under strong injection conditions. The optical chaotic communication system with open-loop configuration is studied using fiber tr...The optical chaotic communication system using open-loop fiber transmission is studied under strong injection conditions. The optical chaotic communication system with open-loop configuration is studied using fiber transmission under strong injection conditions. The performances of fiber links composed of two types of fiber segments in different dispersion compensation maps are compared by testing the quality of the recovered message with different bit rates and encrypted by chaotic modulation （CM） or chaotic shift keying （CSK）. The result indicates that the performance of the pre-compensation map is always worst. Two types of symmetrical maps are identical whatever the encryption method and bit-rate of message are. For the transmitting and the recovering of message of lower bit rate （1 Gb/s）, the post-compensation map is the best scheme. However, for the message of higher bit rate （2.5 Gb/s）, the parameters in communication system need to be modified properly in order to adapt to the high-speed application. Meanwhile, two types of symmetrical maps are the best scheme. In addition, the CM method is superior to the CSK method for high-speed applications. It is in accordance with the result in a back-to-back configuration system.展开更多
An injection-switchable erbium-doped fiber laser （EDFL） with two output ports based on a ring structure is proposed. Wavelength switching together with the switching of the dominating output port of the fiber laser ...An injection-switchable erbium-doped fiber laser （EDFL） with two output ports based on a ring structure is proposed. Wavelength switching together with the switching of the dominating output port of the fiber laser is achieved by controlling the power of a tunable injection laser. The characteristics of the wavelength switching for different levels of the pump laser power and different wavelengths of the injection laser are studied experimentally.展开更多
The optical injection locking of semiconductor lasers to dual-frequency lasers is studied by numerical simulations.The beat-note signals can be effectively transformed to optical frequency combs due to the effective f...The optical injection locking of semiconductor lasers to dual-frequency lasers is studied by numerical simulations.The beat-note signals can be effectively transformed to optical frequency combs due to the effective four wave-mixing in the active semiconductor gain medium. The low-noise Gaussian-like pulse can be obtained by locking the relaxation oscillation and compensating the gain asymmetry. The simulations suggest that pulse trains of width below 30 ps and repetition rate in GHz frequency can be generated simply by the optical injection locking of semiconductor lasers. Since the optical injection locking can broaden the spectrum and amplify the optical power simultaneously, it can be a good initial stage for generating optical frequency combs from dual-frequency lasers by multi-stage of spectral broadening in nonlinear waveguides.展开更多
Enhancing resonance frequency of strong optical studied. Resonance frequency is increased from technique. We experimentally demonstrate that injection-locked semiconductor lasers is experimentally 4.1 to 53.9 GHz by t...Enhancing resonance frequency of strong optical studied. Resonance frequency is increased from technique. We experimentally demonstrate that injection-locked semiconductor lasers is experimentally 4.1 to 53.9 GHz by the optical injection locking （OIL） resonance frequency is strictly equal to the frequency spacing between the cavity modes of the master and slave lasers under strong OIL condition. This result provides valuable information to improve OIL theory.展开更多
The polarization switching（PS） and polarization bistability（PB） characteristics of a 1550-nm vertical-cavity surfaceemitting laser（VCSEL） subjected to orthogonal optical injection are systematically investigated...The polarization switching（PS） and polarization bistability（PB） characteristics of a 1550-nm vertical-cavity surfaceemitting laser（VCSEL） subjected to orthogonal optical injection are systematically investigated.The simulated results show that the PS and polarization-resolved nonlinear dynamical states of the VCSEL are critically dependent on the changing paths of the injected power.The polarization dynamics for different scanning directions of the injected power is presented to explain the polarization evolution during the formation of PS.In the case of forward scanning injected power,with the increase of frequency detuning level between the VCSEL and the injected light,the injected power required for PS gradually increases for negative frequency detuning but exhibits fluctuations for positive frequency detuning.In the case of reversely scanning injected power,the injected power required for PS displays fluctuant changes within the whole frequency detuning range.Specifically,PS may disappear under certain negative frequency detuning and large bias current.Furthermore,the hysteresis width as a function of the frequency detuning is calculated,and the regions for the appearance and disappearance of PB have been determined in the parameter space of the bias current and frequency detuning.展开更多
文摘A master-slave configuration used to control the nonlinear behaviors arising in a vertical cavity surface emitting laser (VCSEL) with strong external optical feedback is established. In terms of bifurcation diagram, time and frequency domain, the influence of the continuous optical injection from the master VCSEL on the nonlinear characteristics of the slave is investigated theoretically. For relatively weak injection, the slave still keeps its intrinsic nonlinear state. With increasing the injection strength, these nonlinear behaviors evolve to periodic fluctuation, and at last are replaced by the steady-state (e.g. the critical injection parameter for steady-state is 1.2 when external cavity's reflectivity and length are 4% and 4 cm, respectively). During this evolution the bifurcation-contraction phenomena are also observed.
基金supported by the National Natural Science Foundation of China (Grant No. 60872123)the Joint Fund of the National Natural Science Foundation and the Guangdong Provincial Natural Science Foundation, China (Grant No. U0835001)the Guangdong Provincial Natural Science Foundation (Grant No. S2011010002144)
文摘The optical chaotic communication system using open-loop fiber transmission is studied under strong injection conditions. The optical chaotic communication system with open-loop configuration is studied using fiber transmission under strong injection conditions. The performances of fiber links composed of two types of fiber segments in different dispersion compensation maps are compared by testing the quality of the recovered message with different bit rates and encrypted by chaotic modulation （CM） or chaotic shift keying （CSK）. The result indicates that the performance of the pre-compensation map is always worst. Two types of symmetrical maps are identical whatever the encryption method and bit-rate of message are. For the transmitting and the recovering of message of lower bit rate （1 Gb/s）, the post-compensation map is the best scheme. However, for the message of higher bit rate （2.5 Gb/s）, the parameters in communication system need to be modified properly in order to adapt to the high-speed application. Meanwhile, two types of symmetrical maps are the best scheme. In addition, the CM method is superior to the CSK method for high-speed applications. It is in accordance with the result in a back-to-back configuration system.
基金This work was partially supported by the Science and Technology Department of Zhejiang Province (No. R104154 and 2004C31095)the Science and Technology Bureau of Hangzhou Municipal Government (No. 20051321B14).
文摘An injection-switchable erbium-doped fiber laser （EDFL） with two output ports based on a ring structure is proposed. Wavelength switching together with the switching of the dominating output port of the fiber laser is achieved by controlling the power of a tunable injection laser. The characteristics of the wavelength switching for different levels of the pump laser power and different wavelengths of the injection laser are studied experimentally.
基金Guizhou Province for Society Development(No.QianKeHe-2013-3125)the Overseas Returning Persons Technology and Innovation Foundation of Guizhou Province of China(No.2016-23)the National Natural Science Foundation of China(Nos.11264006,61465002)
基金Project supported by the National Natural Science Foundation of China(Grant No.62005215)。
文摘The optical injection locking of semiconductor lasers to dual-frequency lasers is studied by numerical simulations.The beat-note signals can be effectively transformed to optical frequency combs due to the effective four wave-mixing in the active semiconductor gain medium. The low-noise Gaussian-like pulse can be obtained by locking the relaxation oscillation and compensating the gain asymmetry. The simulations suggest that pulse trains of width below 30 ps and repetition rate in GHz frequency can be generated simply by the optical injection locking of semiconductor lasers. Since the optical injection locking can broaden the spectrum and amplify the optical power simultaneously, it can be a good initial stage for generating optical frequency combs from dual-frequency lasers by multi-stage of spectral broadening in nonlinear waveguides.
基金supported by the National "973" Program of China(Nos.2012CB315606 and 2010CB328201)
文摘Enhancing resonance frequency of strong optical studied. Resonance frequency is increased from technique. We experimentally demonstrate that injection-locked semiconductor lasers is experimentally 4.1 to 53.9 GHz by the optical injection locking （OIL） resonance frequency is strictly equal to the frequency spacing between the cavity modes of the master and slave lasers under strong OIL condition. This result provides valuable information to improve OIL theory.
基金supported by the National Natural Science Foundation of China(Grant Nos.61178011,61275116,and 61475127)the Natural Science Foundation of Chongqing City,China(Grant No.2012jjB40011)
文摘The polarization switching（PS） and polarization bistability（PB） characteristics of a 1550-nm vertical-cavity surfaceemitting laser（VCSEL） subjected to orthogonal optical injection are systematically investigated.The simulated results show that the PS and polarization-resolved nonlinear dynamical states of the VCSEL are critically dependent on the changing paths of the injected power.The polarization dynamics for different scanning directions of the injected power is presented to explain the polarization evolution during the formation of PS.In the case of forward scanning injected power,with the increase of frequency detuning level between the VCSEL and the injected light,the injected power required for PS gradually increases for negative frequency detuning but exhibits fluctuations for positive frequency detuning.In the case of reversely scanning injected power,the injected power required for PS displays fluctuant changes within the whole frequency detuning range.Specifically,PS may disappear under certain negative frequency detuning and large bias current.Furthermore,the hysteresis width as a function of the frequency detuning is calculated,and the regions for the appearance and disappearance of PB have been determined in the parameter space of the bias current and frequency detuning.
