Gradient index (GRIN) lenses are often used as an optical relay to a sample at a location that is not accessible for a standard microscope. This capability is turning them into an important enabling technology that ex...Gradient index (GRIN) lenses are often used as an optical relay to a sample at a location that is not accessible for a standard microscope. This capability is turning them into an important enabling technology that extends many optical imaging modalities like harmonic laser scanned imaging with micro endoscopic in vivo capabilities as needed in research and diagnostics. These micro endoscopic imaging variants however rely on the light scattering capability of the underlying tissue. Further complications arise from an increased number of optical interfaces and the overall optical performance of a GRIN rod. We have therefore performed a quantitative comparison of the back-scattered second harmonic generation (SHG) signal intensity generated in skin and low-scattering muscle tissue, both obtained with a standard two photon laser scanning microscope (LSM) and a GRIN lens based LSM. We report that the GRIN lens based system sees approximately 1/4 of the net two photon signal detected by the standard LSM. We expect that this value can be generalized to other LSM techniques enhanced by GRIN technology and encourage its use in experimental situations with standard LSM signal to noise ratios of four or higher.展开更多
The most important optical component in an optical fiber endoscope is its objective lens.To achieve a high imaging performance level,the development of an ultra-compact objective lens is thus the key to an ultra-thin ...The most important optical component in an optical fiber endoscope is its objective lens.To achieve a high imaging performance level,the development of an ultra-compact objective lens is thus the key to an ultra-thin optical fiber endoscope.In this work,we use femtosecond laser 3D printing to develop a series of micro objective lenses with different optical designs.The imaging resolution and field-of-view performances of these printed micro objective lenses are investigated via both simulations and experiments.For the first time,multiple micro objective lenses with different fields of view are printed on the end face of a single imaging optical fiber,thus realizing the perfect integration of an optical fiber and objective lenses.This work demonstrates the considerable potential of femtosecond laser 3D printing in the fabrication of micro-optical systems and provides a reliable solution for the development of an ultrathin fiber endoscope.展开更多
An all-silicone zoom lens is fabricated. A tunable metal ringer is fettered around the side edge of the lens. A nylon rope linking a motor is tied, encircling the notch in the metal ringer. While the motor is operatin...An all-silicone zoom lens is fabricated. A tunable metal ringer is fettered around the side edge of the lens. A nylon rope linking a motor is tied, encircling the notch in the metal ringer. While the motor is operating, the rope can shrink or release to change the focal length of the lens. A calculation method is developed to obtain the focal length and the zoom ratio. The testing is carried out in succession. The testing values are compared with the calculated ones, and they tally with each other well. Finally, the imaging performance of the all-silicone lens is demonstrated. The all-silicone lens has potential uses in cellphone cameras, notebook cameras, micro monitor lenses, etc.展开更多
In the paper, the enhanced measurements of the laser micro-jet processing are discussed. In fact, within pure water breakdown threshold of laser, the less focal which focused with the appropriate focusing lens and the...In the paper, the enhanced measurements of the laser micro-jet processing are discussed. In fact, within pure water breakdown threshold of laser, the less focal which focused with the appropriate focusing lens and the small nozzle of water chamber enhance the laser power density ,at the same time, the laser beam transport in the wave guided water with the proper total reflection angle. The laser power which depended on the properties of the diameter, the coupling water chamber and the coupling efficiency of the micro-jet and laser beam expect of the properties of laser.展开更多
In the present study, a micro-scale solar organic Rankine cycle power generation system was developed. The system comprises of a solar collection system based on compound cylindrical Fresnel lens concentrator and an o...In the present study, a micro-scale solar organic Rankine cycle power generation system was developed. The system comprises of a solar collection system based on compound cylindrical Fresnel lens concentrator and an organic Rankine cycle power generation system integrated with a scroll expander. YD320 and R245 fa were used as the heat transfer fluid and the working fluid, respectively. The effects of the evaporation pressure, the degree of superheat, and the mass flow rate of the working fluid were analyzed to evaluate the solar collection efficiency, the electric power output, the thermal efficiency and exergy efficiency of the system. The results illustrate that both the increasing evaporation pressure and decreasing superheat degree have positive impacts on solar collection efficiency. The electric power increases as the evaporation pressure increases, while the thermal efficiency and the exergy efficiency decrease. However, the system overall efficiency decreases slowly due to the increase of solar collection efficiency. The electric power increases with the increment of the working fluid mass flow rate. The increasing mass flow rate has no visible impact on the thermal and exergy efficiencies of organic Rankine cycle subsystem, whereas a slightly increase of the thermal and exergy efficiencies of the integrated system. The electric power decreases with the increase of the superheat degree, whereas the thermal and the exergy efficiencies of the system increase. The system works more suitably with a higher degree of superheat for the small mass flow rate condition.展开更多
In the modern world,women now have tremendous success in every field.They can play,learn,and earn as much as men.But what about safety?Do they have the same secure environment that men and boys do?The answer is“NO”....In the modern world,women now have tremendous success in every field.They can play,learn,and earn as much as men.But what about safety?Do they have the same secure environment that men and boys do?The answer is“NO”.Women and girls have been subjected to numerous incidents,including acid throwing,rape,kidnapping,and harassment.It is common to read a lot of news like this in newspapers every day.These incidents make women feel unsafe in this society.Our freedom came a long time ago,but women still lack complete security in this society.All women cannot fight or shout all the time when some danger is happening to them.What can the physically challenged person and Children do?To make women feel safe,we designed“Wrist Band”using IoT for women safety.As the sensors sense information from the body,it will always update the information such as pulse,temperature,and vibration to the well-wishers through the Blynk app.展开更多
目的:为轻便型视屏神经外科配备便携式显微镜/远视镜实时观察和记录系统。方法:系统由显像设备、成像设备和支架组成。显像设备为Dell便携式计算机;成像设备包括DFK-21AU04 USB CCD摄像头、Computar MLH-10×macro镜头和COPL-40-W...目的:为轻便型视屏神经外科配备便携式显微镜/远视镜实时观察和记录系统。方法:系统由显像设备、成像设备和支架组成。显像设备为Dell便携式计算机;成像设备包括DFK-21AU04 USB CCD摄像头、Computar MLH-10×macro镜头和COPL-40-W同轴光灯头复合体;支架为改造的MA241102便携式气动弹簧摇臂式支架。通过视屏观察(15 cm)深瓶中的干豆、切开的新鲜石榴及成年SD大鼠活体颈总动脉分叉部;在视屏图像引导下阻断成年SD大鼠大脑中动脉。结果:Qy/Fx-0810-Mi/Ma便携式实时观察和记录系统小巧轻便、廉价实用,能够从不同角度观察手术野,工作距离超过54 cm,视屏图像清晰、逼真、有立体感且与实际操作同步。结论:可低成本组建适合轻便型视屏神经外科的便携式显微镜/远视镜实时观察和记录系统。展开更多
文摘Gradient index (GRIN) lenses are often used as an optical relay to a sample at a location that is not accessible for a standard microscope. This capability is turning them into an important enabling technology that extends many optical imaging modalities like harmonic laser scanned imaging with micro endoscopic in vivo capabilities as needed in research and diagnostics. These micro endoscopic imaging variants however rely on the light scattering capability of the underlying tissue. Further complications arise from an increased number of optical interfaces and the overall optical performance of a GRIN rod. We have therefore performed a quantitative comparison of the back-scattered second harmonic generation (SHG) signal intensity generated in skin and low-scattering muscle tissue, both obtained with a standard two photon laser scanning microscope (LSM) and a GRIN lens based LSM. We report that the GRIN lens based system sees approximately 1/4 of the net two photon signal detected by the standard LSM. We expect that this value can be generalized to other LSM techniques enhanced by GRIN technology and encourage its use in experimental situations with standard LSM signal to noise ratios of four or higher.
基金This work was supported by Shenzhen Science and Technology Program(RCYX20200714114524139,Shenzhen Key Laboratory of Ultrafast Laser Micro/Nano Manufacturing ZDSYS20220606100405013)Natural Science Foundation of Guangdong Province(2022B1515120061)National Natural Science Foundation of China(62122057,62075136).
文摘The most important optical component in an optical fiber endoscope is its objective lens.To achieve a high imaging performance level,the development of an ultra-compact objective lens is thus the key to an ultra-thin optical fiber endoscope.In this work,we use femtosecond laser 3D printing to develop a series of micro objective lenses with different optical designs.The imaging resolution and field-of-view performances of these printed micro objective lenses are investigated via both simulations and experiments.For the first time,multiple micro objective lenses with different fields of view are printed on the end face of a single imaging optical fiber,thus realizing the perfect integration of an optical fiber and objective lenses.This work demonstrates the considerable potential of femtosecond laser 3D printing in the fabrication of micro-optical systems and provides a reliable solution for the development of an ultrathin fiber endoscope.
基金supported by the Foundation of Science & Technology Department of Henan Province, China (Grant No. 102102210477)the Foundation of Science & Technology Bureau of Luoyang City, China (Grant No. 1101040A)
文摘An all-silicone zoom lens is fabricated. A tunable metal ringer is fettered around the side edge of the lens. A nylon rope linking a motor is tied, encircling the notch in the metal ringer. While the motor is operating, the rope can shrink or release to change the focal length of the lens. A calculation method is developed to obtain the focal length and the zoom ratio. The testing is carried out in succession. The testing values are compared with the calculated ones, and they tally with each other well. Finally, the imaging performance of the all-silicone lens is demonstrated. The all-silicone lens has potential uses in cellphone cameras, notebook cameras, micro monitor lenses, etc.
文摘In the paper, the enhanced measurements of the laser micro-jet processing are discussed. In fact, within pure water breakdown threshold of laser, the less focal which focused with the appropriate focusing lens and the small nozzle of water chamber enhance the laser power density ,at the same time, the laser beam transport in the wave guided water with the proper total reflection angle. The laser power which depended on the properties of the diameter, the coupling water chamber and the coupling efficiency of the micro-jet and laser beam expect of the properties of laser.
基金supported by the Beijing Municipal Natural Science Foundation,China(Grant No.3194057)
文摘In the present study, a micro-scale solar organic Rankine cycle power generation system was developed. The system comprises of a solar collection system based on compound cylindrical Fresnel lens concentrator and an organic Rankine cycle power generation system integrated with a scroll expander. YD320 and R245 fa were used as the heat transfer fluid and the working fluid, respectively. The effects of the evaporation pressure, the degree of superheat, and the mass flow rate of the working fluid were analyzed to evaluate the solar collection efficiency, the electric power output, the thermal efficiency and exergy efficiency of the system. The results illustrate that both the increasing evaporation pressure and decreasing superheat degree have positive impacts on solar collection efficiency. The electric power increases as the evaporation pressure increases, while the thermal efficiency and the exergy efficiency decrease. However, the system overall efficiency decreases slowly due to the increase of solar collection efficiency. The electric power increases with the increment of the working fluid mass flow rate. The increasing mass flow rate has no visible impact on the thermal and exergy efficiencies of organic Rankine cycle subsystem, whereas a slightly increase of the thermal and exergy efficiencies of the integrated system. The electric power decreases with the increase of the superheat degree, whereas the thermal and the exergy efficiencies of the system increase. The system works more suitably with a higher degree of superheat for the small mass flow rate condition.
文摘In the modern world,women now have tremendous success in every field.They can play,learn,and earn as much as men.But what about safety?Do they have the same secure environment that men and boys do?The answer is“NO”.Women and girls have been subjected to numerous incidents,including acid throwing,rape,kidnapping,and harassment.It is common to read a lot of news like this in newspapers every day.These incidents make women feel unsafe in this society.Our freedom came a long time ago,but women still lack complete security in this society.All women cannot fight or shout all the time when some danger is happening to them.What can the physically challenged person and Children do?To make women feel safe,we designed“Wrist Band”using IoT for women safety.As the sensors sense information from the body,it will always update the information such as pulse,temperature,and vibration to the well-wishers through the Blynk app.
