A near-infrared(NIR) enhanced silicon single-photon avalanche diode(SPAD) detector is proposed using 0.18 μm bipolar-CMOS-DMOS technology. It is based on a deep multiplication region, formed by a junction between the...A near-infrared(NIR) enhanced silicon single-photon avalanche diode(SPAD) detector is proposed using 0.18 μm bipolar-CMOS-DMOS technology. It is based on a deep multiplication region, formed by a junction between the highvoltage P-well(HVPW) and high-voltage buried N+ layer, to enhance the NIR photon detection probability(PDP). Thanks to the lightly doped P-type epitaxial layer, the electric field in the guard ring is reduced and premature breakdown is prevented. In particular, an extra P-type implantation layer(PIL) is added to the HVPW to reduce the breakdown voltage and enhance the device's sensitivity. Further research on the impact of different PIL sizes on the device performance is carried out. It is experimentally shown that at an excess bias voltage of 5 V, the optimized SPAD achieves a dark count rate of 0.64 cps/μm^(2), peak PDP of 54.8% at 555 nm and PDP of 10.53% at 905 nm. The full width at half-maximum of the timing jitter is 285 ps, and the afterpulsing probability is lower than 1.17%. This novel device provides a practical, low-cost solution for high-performance NIR time-of-flight detectors and 3D imaging sensors.展开更多
The idea of the two-photon mazer(microwave amplification via z-motion-induced emission of radiation)is put forward.The dressed states for the interaction of a cascade three-level atom with a quantum cavity field are d...The idea of the two-photon mazer(microwave amplification via z-motion-induced emission of radiation)is put forward.The dressed states for the interaction of a cascade three-level atom with a quantum cavity field are derived.The general quantum theory of the two-photon mazer is established and its emission probability is studied.The effects of the atomic c.m.momentum and of the atom-field detuning are examined.It is found that the two-photon mazer shows new features that differ from both the one-photon mazer and the conventional two-photon micromaser.展开更多
The influence of the single photon laser altimeter range-gate width on the detection probability and ranging accuracy is discussed and analyzed,according to the LiDAR equation,single photon detection equation and the ...The influence of the single photon laser altimeter range-gate width on the detection probability and ranging accuracy is discussed and analyzed,according to the LiDAR equation,single photon detection equation and the Monte Carlo method to simulate the experiment.The simulated results show that the probability of detection is not affected by the range gate,while the probability of false alarm is relative to the gate width.When the gate width is 100 ns,the ranging accuracy can accord with the requirements of satellite laser altimeter.But when the range gate width exceeds 400 ns,ranging accuracy will decline sharply.The noise ratio will be more as long as the range gate to get larger,so the refined filtering algorithm during the data processing is important to extract the useful photons effectively.In order to ensure repeated observation of the same point for 25 times,we deduce the quantitative relation between the footprint size,footprint,and frequency repetition according to the parameters of ICESat-2.The related conclusions can provide some references for the design and the development of the domestic single photon laser altimetry satellite.展开更多
The paper investigates the escape probability for isotropic emitters near a Kerr black hole.We propose a new approach to obtain the escape probability in a general manner,going beyond previous case-by-case studies.Thi...The paper investigates the escape probability for isotropic emitters near a Kerr black hole.We propose a new approach to obtain the escape probability in a general manner,going beyond previous case-by-case studies.This approach is based on studies of the black hole shadow with astrometric observable and can be applied to emitters with an arbitrary 4-velocities and locations,even to the emitters outside of the equatorial plane.We also consider representative examples illustrating how escape probabilities vary with distance,velocity,and inclination angle.Overall,this new approach provides an effective method for studying escape probabilities near Kerr black holes.展开更多
The intensity and number of transmitted multiple scattered photons are calculated for 0.123, 0.320, 0.511,0.662, and 1.115 Me V gamma photons normally incident on slabs of carbon, aluminum, iron, copper, water, muscle...The intensity and number of transmitted multiple scattered photons are calculated for 0.123, 0.320, 0.511,0.662, and 1.115 Me V gamma photons normally incident on slabs of carbon, aluminum, iron, copper, water, muscle,bone, and concrete with thicknesses varying from 1 to 10 mean free paths. The dependence of the transmission probability and energy distribution on the incident energy and material are examined. In general, the obtained results show good agreement with the other values calculated by the Monte Carlo method.展开更多
Backscattering of gamma photons from a material is of fundamental importance in radiation shielding,industrial and medical applications, radiation dosimetry,and non-destructive testing. In Compton scattering, incident...Backscattering of gamma photons from a material is of fundamental importance in radiation shielding,industrial and medical applications, radiation dosimetry,and non-destructive testing. In Compton scattering, incident photons undergo multiple scatterings within the material(target) before exiting. Gamma photons continue to soften in energy as the number of scatterings increases in a thick target; in other words, the energy of gamma photons decreases as the scatterings increase in case of a thick target and results in the generation of singly and multiply scattered events. In this work, the energy distribution of backscattered gamma photons with backscattering intensity and energy probabilities were calculated by using the Monte Carlo method for metallic, biological, and shielding materials with various thicknesses of slab geometry. The materials under study were targeted with gamma photons of 0.279, 0.662, 1.250, and 2.100 Me V energies. In addition, the energy distributions of multiply scattered gamma photons were studied for materials with infinite geometry.The results are presented and discussed in detail by comparing with other Monte Carlo calculations.展开更多
A rigorous theoretical model for Ino.53Gao.47As/InP single photon avalanche diode is utilized to investigate the dependences of single photon quantum efficiency and dark count probability on structure and operation co...A rigorous theoretical model for Ino.53Gao.47As/InP single photon avalanche diode is utilized to investigate the dependences of single photon quantum efficiency and dark count probability on structure and operation condition. In the model, low field impact ionizations in charge and absorption layers are allowed, while avalanche breakdown can occur only in the multiplication layer. The origin of dark counts is discussed and the results indicate that the dominant mechanism that gives rise to dark counts depends on both device structure and operating condition. When the multiplication layer is thicker than a critical thickness or the temperature is higher than a critical value, generation-recombination in the absorption layer is the dominative mechanism; otherwise band-to-band tunneling in the multiplication layer dominates the dark counts. The thicknesses of charge and multiplication layers greatly affect the dark count and the peak single photon quantum efficiency and increasing the multiplication layer width may reduce the dark count probability and increase the peak single photon quantum efficiency. However, when the multiplication layer width exceeds 1 μm, the peak single photon quantum efficiency increases slowly and it is finally saturated at the quantum efficiency of the single photon avalanche diodes.展开更多
By virtue of the technique of integration within an ordered product （IWOP） of operators and the properties of the inverses of annihilation and creation operators of f-oscillator, this paper obtains two new types of ...By virtue of the technique of integration within an ordered product （IWOP） of operators and the properties of the inverses of annihilation and creation operators of f-oscillator, this paper obtains two new types of squeezed operators and f-analogues of squeezed one-photon states, which are quite different from ones constructed by Song and Fan （Phys. Lett. A 294 （2002） 66）. Subsequently, some nonclassical properties of the states are investigated in detail.展开更多
CONSPECTUS:The preserved bosonic nature of surface plasmon polaritons from incident photons allows plasmonic nanomaterials to serve as effective photonic platforms.The strong light−matter interaction occurring at the ...CONSPECTUS:The preserved bosonic nature of surface plasmon polaritons from incident photons allows plasmonic nanomaterials to serve as effective photonic platforms.The strong light−matter interaction occurring at the surface concentrates light energy within a narrow region,thereby altering the local density of optical states.This modified photonic environment is typically expressed as near-field enhancement and improves the transition probability of nearby molecules or quantum emitters.展开更多
Single-photon detection(SPD)technologies have been applied to underwater optical imaging to overcome the strong attenuation of seawater.However,external photon noise,resulting from the natural light,hinders their furt...Single-photon detection(SPD)technologies have been applied to underwater optical imaging to overcome the strong attenuation of seawater.However,external photon noise,resulting from the natural light,hinders their further applications due to the extreme sensitivity of SPD and a weakly received optical signal.In this work,we performed noise-resistant underwater correlated biphoton imaging(CPI)to partly solve the influence of the external noise,through a home-built super-bunching laser generated by the stochastic nonlinear interaction between a picosecond laser and a photonic crystal fiber.Compared with a coherent laser,the probabilities of generated bundle N-photons(N≥2)of the super-bunching laser have been enhanced by at least one order of magnitude,enabling CPI under weak light intensity.We experimentally demonstrated CPI with reasonable imaging contrast under the noise-to-signal ratio(NSR)up to 10~3,and the noise-resistant performance has been improved by at least two orders of magnitude compared to that of the single-photon imaging technology.We further achieved underwater CPI with good imaging contrast under NSR of 150,in a glass tank with a length of 10 m with Jerlov typeⅢwater(an attenuation coefficient of 0.176 m^(-1)).These results break the limits of underwater imaging through classical coherent lasers and may offer many enhanced imaging applications through our super-bunching laser,such as long-range target tracking and deep-sea optical exploration under noisy environments.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 62171233)the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20241891)the Jiangsu Province Postgraduate Innovation Program (Grant No. KYCX23_0999)。
文摘A near-infrared(NIR) enhanced silicon single-photon avalanche diode(SPAD) detector is proposed using 0.18 μm bipolar-CMOS-DMOS technology. It is based on a deep multiplication region, formed by a junction between the highvoltage P-well(HVPW) and high-voltage buried N+ layer, to enhance the NIR photon detection probability(PDP). Thanks to the lightly doped P-type epitaxial layer, the electric field in the guard ring is reduced and premature breakdown is prevented. In particular, an extra P-type implantation layer(PIL) is added to the HVPW to reduce the breakdown voltage and enhance the device's sensitivity. Further research on the impact of different PIL sizes on the device performance is carried out. It is experimentally shown that at an excess bias voltage of 5 V, the optimized SPAD achieves a dark count rate of 0.64 cps/μm^(2), peak PDP of 54.8% at 555 nm and PDP of 10.53% at 905 nm. The full width at half-maximum of the timing jitter is 285 ps, and the afterpulsing probability is lower than 1.17%. This novel device provides a practical, low-cost solution for high-performance NIR time-of-flight detectors and 3D imaging sensors.
基金Supported by the Senior Visiting Scholar Project of Chinese Academy of Sciences。
文摘The idea of the two-photon mazer(microwave amplification via z-motion-induced emission of radiation)is put forward.The dressed states for the interaction of a cascade three-level atom with a quantum cavity field are derived.The general quantum theory of the two-photon mazer is established and its emission probability is studied.The effects of the atomic c.m.momentum and of the atom-field detuning are examined.It is found that the two-photon mazer shows new features that differ from both the one-photon mazer and the conventional two-photon micromaser.
基金National Natural Science Foundation of China(No.41871382)Open Foundation of the Key Laboratory of Space Active Opto-electronics Technologyand Chinese Academy of Sciences(No.2018-ZDKF-1)。
文摘The influence of the single photon laser altimeter range-gate width on the detection probability and ranging accuracy is discussed and analyzed,according to the LiDAR equation,single photon detection equation and the Monte Carlo method to simulate the experiment.The simulated results show that the probability of detection is not affected by the range gate,while the probability of false alarm is relative to the gate width.When the gate width is 100 ns,the ranging accuracy can accord with the requirements of satellite laser altimeter.But when the range gate width exceeds 400 ns,ranging accuracy will decline sharply.The noise ratio will be more as long as the range gate to get larger,so the refined filtering algorithm during the data processing is important to extract the useful photons effectively.In order to ensure repeated observation of the same point for 25 times,we deduce the quantitative relation between the footprint size,footprint,and frequency repetition according to the parameters of ICESat-2.The related conclusions can provide some references for the design and the development of the domestic single photon laser altimetry satellite.
基金supported by the National Key Research and Development Program of China, Grant No. 2020YFC2201502by grants from the National Natural Science Foundation of China (Grant No. 11991052)the Key Research Program of Frontier Sciences, CAS, Grant No. ZDBS-LY-7009
文摘The paper investigates the escape probability for isotropic emitters near a Kerr black hole.We propose a new approach to obtain the escape probability in a general manner,going beyond previous case-by-case studies.This approach is based on studies of the black hole shadow with astrometric observable and can be applied to emitters with an arbitrary 4-velocities and locations,even to the emitters outside of the equatorial plane.We also consider representative examples illustrating how escape probabilities vary with distance,velocity,and inclination angle.Overall,this new approach provides an effective method for studying escape probabilities near Kerr black holes.
文摘The intensity and number of transmitted multiple scattered photons are calculated for 0.123, 0.320, 0.511,0.662, and 1.115 Me V gamma photons normally incident on slabs of carbon, aluminum, iron, copper, water, muscle,bone, and concrete with thicknesses varying from 1 to 10 mean free paths. The dependence of the transmission probability and energy distribution on the incident energy and material are examined. In general, the obtained results show good agreement with the other values calculated by the Monte Carlo method.
文摘Backscattering of gamma photons from a material is of fundamental importance in radiation shielding,industrial and medical applications, radiation dosimetry,and non-destructive testing. In Compton scattering, incident photons undergo multiple scatterings within the material(target) before exiting. Gamma photons continue to soften in energy as the number of scatterings increases in a thick target; in other words, the energy of gamma photons decreases as the scatterings increase in case of a thick target and results in the generation of singly and multiply scattered events. In this work, the energy distribution of backscattered gamma photons with backscattering intensity and energy probabilities were calculated by using the Monte Carlo method for metallic, biological, and shielding materials with various thicknesses of slab geometry. The materials under study were targeted with gamma photons of 0.279, 0.662, 1.250, and 2.100 Me V energies. In addition, the energy distributions of multiply scattered gamma photons were studied for materials with infinite geometry.The results are presented and discussed in detail by comparing with other Monte Carlo calculations.
基金supported by the National Basic Research Program of China (Grant Nos. G2001039302 and 007CB307001)the Guangdong Provincial Key Technology Research and Development Program,China (Grant No. 2007B010400009)
文摘A rigorous theoretical model for Ino.53Gao.47As/InP single photon avalanche diode is utilized to investigate the dependences of single photon quantum efficiency and dark count probability on structure and operation condition. In the model, low field impact ionizations in charge and absorption layers are allowed, while avalanche breakdown can occur only in the multiplication layer. The origin of dark counts is discussed and the results indicate that the dominant mechanism that gives rise to dark counts depends on both device structure and operating condition. When the multiplication layer is thicker than a critical thickness or the temperature is higher than a critical value, generation-recombination in the absorption layer is the dominative mechanism; otherwise band-to-band tunneling in the multiplication layer dominates the dark counts. The thicknesses of charge and multiplication layers greatly affect the dark count and the peak single photon quantum efficiency and increasing the multiplication layer width may reduce the dark count probability and increase the peak single photon quantum efficiency. However, when the multiplication layer width exceeds 1 μm, the peak single photon quantum efficiency increases slowly and it is finally saturated at the quantum efficiency of the single photon avalanche diodes.
基金Project supported by the National Natural Science Foundation of China （Grant No 10574060） and the Natural Science Foundation of Shandong Province, China （Grant No Y2004A09）.
文摘By virtue of the technique of integration within an ordered product （IWOP） of operators and the properties of the inverses of annihilation and creation operators of f-oscillator, this paper obtains two new types of squeezed operators and f-analogues of squeezed one-photon states, which are quite different from ones constructed by Song and Fan （Phys. Lett. A 294 （2002） 66）. Subsequently, some nonclassical properties of the states are investigated in detail.
基金Supported by the National Natural Science Foundation of China(NSFC)(62174166,11991063,U2241219)Shanghai Municipal Science and Technology Major Project(2019SHZDZX01,22JC1402902)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB43010200)。
基金supported by the National Research Foundation of Korea(NRF)grants,funded by Korean government(MSIT)(NRF-2021R1A2C3010083&RS-2024-00397807)Nano·Material Technology Development Program through the NRF,funded by Ministry of Science and ICT(RS-2024-00450828).
文摘CONSPECTUS:The preserved bosonic nature of surface plasmon polaritons from incident photons allows plasmonic nanomaterials to serve as effective photonic platforms.The strong light−matter interaction occurring at the surface concentrates light energy within a narrow region,thereby altering the local density of optical states.This modified photonic environment is typically expressed as near-field enhancement and improves the transition probability of nearby molecules or quantum emitters.
基金supported by the National Natural Science Foundation of China(Nos.U22A2091,62222509,U23A20380,62127817,and 62205187)the Shanxi Province Science and Technology Innovation Talent Team(No.202204051001014)+2 种基金the Key Research and Development Project of Shanxi Province(No.202102030201007)the Program for Changjiang Scholars and Innovative Research Team(PCSIRT)(No.IRT_17R70)the 111 Projects(No.D18001)。
文摘Single-photon detection(SPD)technologies have been applied to underwater optical imaging to overcome the strong attenuation of seawater.However,external photon noise,resulting from the natural light,hinders their further applications due to the extreme sensitivity of SPD and a weakly received optical signal.In this work,we performed noise-resistant underwater correlated biphoton imaging(CPI)to partly solve the influence of the external noise,through a home-built super-bunching laser generated by the stochastic nonlinear interaction between a picosecond laser and a photonic crystal fiber.Compared with a coherent laser,the probabilities of generated bundle N-photons(N≥2)of the super-bunching laser have been enhanced by at least one order of magnitude,enabling CPI under weak light intensity.We experimentally demonstrated CPI with reasonable imaging contrast under the noise-to-signal ratio(NSR)up to 10~3,and the noise-resistant performance has been improved by at least two orders of magnitude compared to that of the single-photon imaging technology.We further achieved underwater CPI with good imaging contrast under NSR of 150,in a glass tank with a length of 10 m with Jerlov typeⅢwater(an attenuation coefficient of 0.176 m^(-1)).These results break the limits of underwater imaging through classical coherent lasers and may offer many enhanced imaging applications through our super-bunching laser,such as long-range target tracking and deep-sea optical exploration under noisy environments.
