We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector （DBR） composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase sec...We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector （DBR） composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase section, and an active gain section. The gain section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing （QWI） technique to provide low-absorption loss grating and passive phase section in the fabrication process. By tuning the injection currents on the DBR and the gain sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature.展开更多
A novel dual-depletion-region electroabsorption modulator(DDR-EAM)based on InP at 1550nm is fabricated.The measured capacitance and extinction ratio of the DDR-EAM reveal that the dual depletion region structure can r...A novel dual-depletion-region electroabsorption modulator(DDR-EAM)based on InP at 1550nm is fabricated.The measured capacitance and extinction ratio of the DDR-EAM reveal that the dual depletion region structure can reduce the device capacitance significantly without any degradation of extinction ratio.Moreover,the bandwidth of the DDR-EAM predicted by using an equivalent circuit model is larger than twice the bandwidth of the conventional lumped-electrode EAM(L-EAM).展开更多
The distinct period doubling behaviour in a 10 GHz gain-switched （GS） DFB laser is experimentally investigated in frequency domain and in time domain. The period doubling occurs as the frequency of the rf driving si...The distinct period doubling behaviour in a 10 GHz gain-switched （GS） DFB laser is experimentally investigated in frequency domain and in time domain. The period doubling occurs as the frequency of the rf driving signal is close to or higher than the-3 dB cutoff frequency of the DFB laser diode, and the amplitude of the rf driving signal required to achieve period doubling increases linearly with the increasing bias current of the laser diode.展开更多
We present the design and optimization of evanescently coupled waveguide photodiodes（EC-WPDs） based on the coupling modes theory and the beam propagation method.Efficient focalization of the optical power in the abs...We present the design and optimization of evanescently coupled waveguide photodiodes（EC-WPDs） based on the coupling modes theory and the beam propagation method.Efficient focalization of the optical power in the absorber is achieved by an appropriate choice of index matching layers of EC-WPDs.Numerical simulation shows that high-speed（40 GHz）,high quantum efficiency（81%） and high linearity photodiodes can be achieved, and EC-WPDs are promising devices for future optical communication systems.展开更多
A selected area growth wavelength converter based on a PD-EAM optical logic gate for WDM application is presented, integrating an EML transmitter and a SOA-PD receiver. The design, fabrication, and DC characters were ...A selected area growth wavelength converter based on a PD-EAM optical logic gate for WDM application is presented, integrating an EML transmitter and a SOA-PD receiver. The design, fabrication, and DC characters were analyzed. A 2 Gb/s NRZ signal based on the C-band wavelength converted to 1555 nm with the highest extinction ratio of 7 dB was achieved and wavelength converted eye diagrams with eyes opened were presented.展开更多
A novel scheme for pulse generation with a self-cascaded electroabsorption modulator is presented and experimentally demonstrated at 10 GHz. In the case of optimal tuning of time delay in the fibre loop, the improveme...A novel scheme for pulse generation with a self-cascaded electroabsorption modulator is presented and experimentally demonstrated at 10 GHz. In the case of optimal tuning of time delay in the fibre loop, the improvement of 50% on pulsewidth with improved extinction ratio is obtained and the narrowest pulse generated with this method is about 11ps.展开更多
A 1.56 μm passively mode-locked laser diode with a two-section tensile strained multi-quantum-well structure is fabricated.Without any external pulse compression,a Lorentz pulse train with a pulse width of 1.03 ps an...A 1.56 μm passively mode-locked laser diode with a two-section tensile strained multi-quantum-well structure is fabricated.Without any external pulse compression,a Lorentz pulse train with a pulse width of 1.03 ps and a repetition rate of 35.6 GHz is obtained,which is one of the best results that have been reported on similar devices.The optical pulse has a 300 kHz line width and a 50dB peak over the noise floor in the photodetected radio-frequency electrical spectrum.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60736036 and 61021003)the National Basic Research Program of China (Grant No. 2011CB301702)
文摘We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector （DBR） composite resonant cavity. The device consists of three sections, a DBR grating section, a passive phase section, and an active gain section. The gain section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing （QWI） technique to provide low-absorption loss grating and passive phase section in the fabrication process. By tuning the injection currents on the DBR and the gain sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature.
基金by the National Natural Science Foundation of China under Grant Nos 60736036 and 61021003the National Basic Research Program of China under Grant No 2011CB301702the National High-Technology Research and Development Program of China under Grant Nos 2009AA03Z442 and 2011AA010303。
文摘A novel dual-depletion-region electroabsorption modulator(DDR-EAM)based on InP at 1550nm is fabricated.The measured capacitance and extinction ratio of the DDR-EAM reveal that the dual depletion region structure can reduce the device capacitance significantly without any degradation of extinction ratio.Moreover,the bandwidth of the DDR-EAM predicted by using an equivalent circuit model is larger than twice the bandwidth of the conventional lumped-electrode EAM(L-EAM).
基金Supported by the National Natural Science Foundation of China under Grant No 90401025, the Ministry of Education of China under Grant No NCET-04-0116 and 105036.
文摘The distinct period doubling behaviour in a 10 GHz gain-switched （GS） DFB laser is experimentally investigated in frequency domain and in time domain. The period doubling occurs as the frequency of the rf driving signal is close to or higher than the-3 dB cutoff frequency of the DFB laser diode, and the amplitude of the rf driving signal required to achieve period doubling increases linearly with the increasing bias current of the laser diode.
基金Project supported by the State Key Development Program for Basic Research of China(No.2011CB301702)the National Natural Science Foundation of China(Nos.61006041,61001121,60736036,60932004)the Fundamental Research Funds for the Central Universities
文摘We present the design and optimization of evanescently coupled waveguide photodiodes（EC-WPDs） based on the coupling modes theory and the beam propagation method.Efficient focalization of the optical power in the absorber is achieved by an appropriate choice of index matching layers of EC-WPDs.Numerical simulation shows that high-speed（40 GHz）,high quantum efficiency（81%） and high linearity photodiodes can be achieved, and EC-WPDs are promising devices for future optical communication systems.
基金Project supported by the Nationa lHigh Technology Research and Development Program of China(Nos.2011AA010303,2012AA012203)the State Key Program for Basic Research of China(No.2011CB301702)the National Natural Science Foundation of China(Nos.61021003,61090392)
文摘A selected area growth wavelength converter based on a PD-EAM optical logic gate for WDM application is presented, integrating an EML transmitter and a SOA-PD receiver. The design, fabrication, and DC characters were analyzed. A 2 Gb/s NRZ signal based on the C-band wavelength converted to 1555 nm with the highest extinction ratio of 7 dB was achieved and wavelength converted eye diagrams with eyes opened were presented.
基金Supported by the National Natural Science Foundation of China under Grant Nos 90401025 and 60577033, and the Ministry of Education of China under Grant No NCET-04-0116.
文摘A novel scheme for pulse generation with a self-cascaded electroabsorption modulator is presented and experimentally demonstrated at 10 GHz. In the case of optimal tuning of time delay in the fibre loop, the improvement of 50% on pulsewidth with improved extinction ratio is obtained and the narrowest pulse generated with this method is about 11ps.
文摘A 1.56 μm passively mode-locked laser diode with a two-section tensile strained multi-quantum-well structure is fabricated.Without any external pulse compression,a Lorentz pulse train with a pulse width of 1.03 ps and a repetition rate of 35.6 GHz is obtained,which is one of the best results that have been reported on similar devices.The optical pulse has a 300 kHz line width and a 50dB peak over the noise floor in the photodetected radio-frequency electrical spectrum.
