An all-optical clock recovery scheme based on monolithic amplified feedback DFB laser （AFL） diode is proposed for nonreturn-to-zero （NRZ） quadrature phase shift keying （QPSK） format signals. By using a preproces...An all-optical clock recovery scheme based on monolithic amplified feedback DFB laser （AFL） diode is proposed for nonreturn-to-zero （NRZ） quadrature phase shift keying （QPSK） format signals. By using a preprocessing stage, clock recovery （CR） is successfully demonstrated for 40-Gbaud NRZ-QPSK signals based on this scheme. The dependence of the timing jitter of the recovered clock on the optical power of the injected signal is investigated. A minimum timing jitter of 362.8 fs （integrated within a frequency range from 10 Hz to 10 MHz） is obtained.展开更多
We experimentally demonstrate all-optical clock recovery for 100 Gb/s return-to-zero on-off keying signals based on a monolithic dual-mode distributed Bragg reflector （DBR） laser, which can realize both mode spacing...We experimentally demonstrate all-optical clock recovery for 100 Gb/s return-to-zero on-off keying signals based on a monolithic dual-mode distributed Bragg reflector （DBR） laser, which can realize both mode spacing and wavelength tuning. By using a coherent injection locking scheme, a 100 GHz optical clock can be recovered with a timing jitter of 530 fs, which is derived by an optical sampling oscilloscope from both the phase noise and the power fluctuation. Furthermore, for degraded injection signals with an optical signal-to-noise ratio as low as 4.1 dB and a 25 km long distance transmission, good-quality optical clocks are all successfully recovered.展开更多
As the key part of chip-scale atomic clocks(CSACs), the vapor cell directly determines the volume, stability,and power consumption of the CSAC. The reduction of the power consumption and CSAC volumes demands the manuf...As the key part of chip-scale atomic clocks(CSACs), the vapor cell directly determines the volume, stability,and power consumption of the CSAC. The reduction of the power consumption and CSAC volumes demands the manufacture of corresponding vapor cells. This overview presents the research development of vapor cells of the past few years and analyzes the shortages of the current preparation technology. By comparing several different vapor cell preparation methods, we successfully realized the micro-fabrication of vapor cells using anodic bonding and deep silicon etching. This cell fabrication method is simple and effective in avoiding weak bonding strengths caused by alkali metal volatilization during anodic bonding under high temperatures.Finally, the vapor cell D2 line was characterized via optical-absorption resonance. According to the results,the proposed method is suitable for CSAC.展开更多
As a rule,stability calculation of atomic clock requires observations with equivalent sampling interval.Apart from atomic clocks in laboratory,orbital atomic clock stability calculations are impacted of raw data sampl...As a rule,stability calculation of atomic clock requires observations with equivalent sampling interval.Apart from atomic clocks in laboratory,orbital atomic clock stability calculations are impacted of raw data sampling intervals,noncontinuous time series,non-data segment,frequency drift,and other factors.So,the calculated stability results are not so exact.In this article,the impacts of kinds of error sources on Allan and Hadamard variances are analyzed using global positioning system satellite precise clock offset data.And the laws of variety are summarized.展开更多
基金This work was supported by the National ＂973＂ Program of China （No. 2011CB301702）, in part by the National ＂863＂ Program of China （No. 2013AA014202）, and the National Natural Science Foundation of China （Nos. 61201103, 61335009, 61274045, and 61205031）.
文摘An all-optical clock recovery scheme based on monolithic amplified feedback DFB laser （AFL） diode is proposed for nonreturn-to-zero （NRZ） quadrature phase shift keying （QPSK） format signals. By using a preprocessing stage, clock recovery （CR） is successfully demonstrated for 40-Gbaud NRZ-QPSK signals based on this scheme. The dependence of the timing jitter of the recovered clock on the optical power of the injected signal is investigated. A minimum timing jitter of 362.8 fs （integrated within a frequency range from 10 Hz to 10 MHz） is obtained.
基金supported by the National 973 Program of China(Nos.2011CB301702 and 2011CB301703)the National Natural Science Foundation of China(Nos.61201103,61335009,and 61321063)
文摘We experimentally demonstrate all-optical clock recovery for 100 Gb/s return-to-zero on-off keying signals based on a monolithic dual-mode distributed Bragg reflector （DBR） laser, which can realize both mode spacing and wavelength tuning. By using a coherent injection locking scheme, a 100 GHz optical clock can be recovered with a timing jitter of 530 fs, which is derived by an optical sampling oscilloscope from both the phase noise and the power fluctuation. Furthermore, for degraded injection signals with an optical signal-to-noise ratio as low as 4.1 dB and a 25 km long distance transmission, good-quality optical clocks are all successfully recovered.
基金supported by the National Key Research and Development Program of China(No.2017YFB0503200)the National Natural Science Foundation of China(Nos.61675185 and 61875250)+3 种基金the Natural Science Foundation of Shanxi Province(No.201701D121065)Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Provincethe Program for the Top Young and Middle-Aged Innovative Talents of HigherLearning Institutions of Shanxisponsored by the Fund for Shanxi ‘1331 Project’ Key Subject Construction
文摘As the key part of chip-scale atomic clocks(CSACs), the vapor cell directly determines the volume, stability,and power consumption of the CSAC. The reduction of the power consumption and CSAC volumes demands the manufacture of corresponding vapor cells. This overview presents the research development of vapor cells of the past few years and analyzes the shortages of the current preparation technology. By comparing several different vapor cell preparation methods, we successfully realized the micro-fabrication of vapor cells using anodic bonding and deep silicon etching. This cell fabrication method is simple and effective in avoiding weak bonding strengths caused by alkali metal volatilization during anodic bonding under high temperatures.Finally, the vapor cell D2 line was characterized via optical-absorption resonance. According to the results,the proposed method is suitable for CSAC.
基金This work was supported by the National Natural Science Foundation of China(No.41074020).
文摘As a rule,stability calculation of atomic clock requires observations with equivalent sampling interval.Apart from atomic clocks in laboratory,orbital atomic clock stability calculations are impacted of raw data sampling intervals,noncontinuous time series,non-data segment,frequency drift,and other factors.So,the calculated stability results are not so exact.In this article,the impacts of kinds of error sources on Allan and Hadamard variances are analyzed using global positioning system satellite precise clock offset data.And the laws of variety are summarized.
