We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD ...We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD system. The system monitors changes in key rates and controls it is own operation automatically. The system achieves its optimal performance within three seconds of operation, which includes a sifted key rate of 5.5 kbps and a quantum bit error rate of less than 2% after an abrupt temperature variation along the 25 km quantum channel. The system also operates well over a 24 h period while completing more than 60 active optical path length compensations.展开更多
Controlling the tissue temperature rise during retinal laser therapy is essential for predictable outcomes,especially at non-damaging settings.We demonstrate a method for determining the temperature rise in the retina...Controlling the tissue temperature rise during retinal laser therapy is essential for predictable outcomes,especially at non-damaging settings.We demonstrate a method for determining the temperature rise in the retina using phasesensitive optical coherence tomography(pOCT)in vivo.Measurements based on the thermally induced optical path length changes(ΔOPL)in the retina during a 10-ms laser pulse allow detection of the temperature rise with a precision less than 1℃,which is sufficient for calibration of the laser power for patient-specific non-damaging therapy.We observed a significant difference in confinement of the retinal deformations between the normal and the degenerate retina:in wild-type rats,thermal deformations are localized between the retinal pigment epithelium(RPE)and the photoreceptors’inner segments(IS),as opposed to a deep penetration of the deformations into the inner retinal layers in the degenerate retina.This implies the presence of a structural component within healthy photoreceptors that dampens the tissue expansion induced by the laser heating of the RPE and pigmented choroid.We hypothesize that the thin and soft cilium connecting the inner and outer segments(IS,OS)of photoreceptors may absorb the deformations of the OS and thereby preclude the tissue expansion further inward.Striking difference in the confinement of the retinal deformations induced by a laser pulse in healthy and degenerate retina may be used as a biomechanical diagnostic tool for the characterization of photoreceptors degeneration.展开更多
In this paper, the light trapping characteristics of glass substrate with hemisphere pit （HP） arrays in thin film Si solar cells are theoretically studied via a numerical approach. It is found that the HP glass subs...In this paper, the light trapping characteristics of glass substrate with hemisphere pit （HP） arrays in thin film Si solar cells are theoretically studied via a numerical approach. It is found that the HP glass substrate has good antireflection properties. Its surface reflectance can be reduced by - 50% compared with planar glass. The HP arrays can make the unabsorbed light return to the absorbing layer of solar cells, and the ratio of second absorption approximately equals 30%. Thus, the glass substrate with the hemisphere pit arrays （HP glass） can effectively reduce the total reflectivity of a solar celt from 20% to 13%. The lip glass can also prolong the optical path length. The numerical results show that the total optical path length of the thin film Si solar cell covered with the HP glass increases from 2ω to 409. These results are basically consistent with the experimental results.展开更多
In the field of absorption spectroscopy,the multipass cell[MPC]is one of the key elements.It has the advantages of simple structure,easy adjustment,and high spectral coverage,which is an effective way to improve the d...In the field of absorption spectroscopy,the multipass cell[MPC]is one of the key elements.It has the advantages of simple structure,easy adjustment,and high spectral coverage,which is an effective way to improve the detection sensitivity of gas sensing systems such as tunable diode laser absorption spectroscopy.This invited paper summarizes the design theory and the research results of some mainstream types of MPCs based on two mirrors and more than two mirrors in recent years,and briefly introduces the application of some processed products.The design theory of modified ABCD matrix and vector reflection principle are explained in detail.Finally,trends in its development are predicted.展开更多
基金was supported by the ICT R&D programs of Ministry of Science, ICT and Future Planning/Institute for Information & Communications Technology Promotion (Grant No. B0101-16-1355)the Korea Institute of Science and Technology research program (Grant No. 2E27231)Korea Institute of Science and Technology-Electronics And Telecommunications Research Institute research program (Grant No. 2V05340)
文摘We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD system. The system monitors changes in key rates and controls it is own operation automatically. The system achieves its optimal performance within three seconds of operation, which includes a sifted key rate of 5.5 kbps and a quantum bit error rate of less than 2% after an abrupt temperature variation along the 25 km quantum channel. The system also operates well over a 24 h period while completing more than 60 active optical path length compensations.
基金funded by the National Institutes of Health(U01 EY032055)Air Force Office of Scientific Research(FA9550-20-1-0186)Research to Prevent Blindness.
文摘Controlling the tissue temperature rise during retinal laser therapy is essential for predictable outcomes,especially at non-damaging settings.We demonstrate a method for determining the temperature rise in the retina using phasesensitive optical coherence tomography(pOCT)in vivo.Measurements based on the thermally induced optical path length changes(ΔOPL)in the retina during a 10-ms laser pulse allow detection of the temperature rise with a precision less than 1℃,which is sufficient for calibration of the laser power for patient-specific non-damaging therapy.We observed a significant difference in confinement of the retinal deformations between the normal and the degenerate retina:in wild-type rats,thermal deformations are localized between the retinal pigment epithelium(RPE)and the photoreceptors’inner segments(IS),as opposed to a deep penetration of the deformations into the inner retinal layers in the degenerate retina.This implies the presence of a structural component within healthy photoreceptors that dampens the tissue expansion induced by the laser heating of the RPE and pigmented choroid.We hypothesize that the thin and soft cilium connecting the inner and outer segments(IS,OS)of photoreceptors may absorb the deformations of the OS and thereby preclude the tissue expansion further inward.Striking difference in the confinement of the retinal deformations induced by a laser pulse in healthy and degenerate retina may be used as a biomechanical diagnostic tool for the characterization of photoreceptors degeneration.
基金Project supported by the National High-Tech Research and Development Program of China(Grant No.2011AA050518)
文摘In this paper, the light trapping characteristics of glass substrate with hemisphere pit （HP） arrays in thin film Si solar cells are theoretically studied via a numerical approach. It is found that the HP glass substrate has good antireflection properties. Its surface reflectance can be reduced by - 50% compared with planar glass. The HP arrays can make the unabsorbed light return to the absorbing layer of solar cells, and the ratio of second absorption approximately equals 30%. Thus, the glass substrate with the hemisphere pit arrays （HP glass） can effectively reduce the total reflectivity of a solar celt from 20% to 13%. The lip glass can also prolong the optical path length. The numerical results show that the total optical path length of the thin film Si solar cell covered with the HP glass increases from 2ω to 409. These results are basically consistent with the experimental results.
基金supported by the National Natural Science Foundation of China(Nos.62275065,62022032,and 61875047)Natural Science Foundation of Heilongjiang Province of China(No.YQ2019F006)。
文摘In the field of absorption spectroscopy,the multipass cell[MPC]is one of the key elements.It has the advantages of simple structure,easy adjustment,and high spectral coverage,which is an effective way to improve the detection sensitivity of gas sensing systems such as tunable diode laser absorption spectroscopy.This invited paper summarizes the design theory and the research results of some mainstream types of MPCs based on two mirrors and more than two mirrors in recent years,and briefly introduces the application of some processed products.The design theory of modified ABCD matrix and vector reflection principle are explained in detail.Finally,trends in its development are predicted.
