A moireis an interference pattern that appears when two different periodic structures are overlaid.The image created is extremely sensitive to small variations in the original layers and is thus very interesting for a...A moireis an interference pattern that appears when two different periodic structures are overlaid.The image created is extremely sensitive to small variations in the original layers and is thus very interesting for anti-counterfeit protection.We present a microfabricated 1D moire enabling complex high-resolution patterns as a significantly improved security feature that cannot be reproduced using standard printing methods.Furthermore,we demonstrate,theoretically and experimentally,that a microscopic deviation from the original design results in a macroscopic variation in the moire that is clearly visible to the naked eye.The record resolution achieved in the elements fabricated and the increased design freedom,make these high-resolution moires excellent candidates for a variety of visually appealing security applications.展开更多
By using a specialty optical fiber, a series of powerful microparticle manipulation tools, including optical tweezers, a micro-optical hand, and an optical gun, are developed and demonstrated. In this paper,a review o...By using a specialty optical fiber, a series of powerful microparticle manipulation tools, including optical tweezers, a micro-optical hand, and an optical gun, are developed and demonstrated. In this paper,a review of our research activities on the optical manipulation of microparticles is presented. In particular,we will describe a kind of specialty optical fiber designed and fabricated for building optical trapping and manipulating tools. The performances of annular core fiber-based optical tweezers, a multicore fiber-based micro-optical hand, and a coaxial dual waveguide fiber-based optical gun are demonstrated as examples of applications and discussed in detail. The fiber can be used in cell manipulation in life science and drug response in medicine.展开更多
Microlenses fabricated using flexible elastomers can be tuned in focal length by application of controlled strain.By varying the strain azimuthally,the lenses may be deformed asymmetrically such that aberrations may b...Microlenses fabricated using flexible elastomers can be tuned in focal length by application of controlled strain.By varying the strain azimuthally,the lenses may be deformed asymmetrically such that aberrations may be controlled.This approach is used to tune the astigmatism of the tunable lenses,and it is shown that the generated wavefront may be accurately controlled.The lens presented here has an initial focal length of 32.6 mm and a tuning range of 12.3 mm for approximately 10%applied strain.The range of directly tunable Zernike polynomials representing astigmatism is about 3 mm,while the secondary lens errors,which cannot be tuned directly,vary only by about 0.2 mm.展开更多
Several approaches to fabricate micro optical elements by use of half tone masks are studied and compared. It is shown that half tone masks employed in filtering image systems can obtain gray patterns with considerabl...Several approaches to fabricate micro optical elements by use of half tone masks are studied and compared. It is shown that half tone masks employed in filtering image systems can obtain gray patterns with considerably high precision, but it is hard to operate from the viewpoint of operation. The method using contacting lithography technology or laser ablation can be easily operated with the cost of reducing fabrication precision and the trouble of choosing appropriate materials. For all of these methods, the coding of half tone masks with corrections for the nonlinear characteristics of coding, imaging and photoresist is recommended.展开更多
We propose a core rotation-sensing element for improving the sensitivity of the micro-optical gyroscope using the large nonreciprocal effect with a photonic crystal.The sharp transmission peak of electromagnetically i...We propose a core rotation-sensing element for improving the sensitivity of the micro-optical gyroscope using the large nonreciprocal effect with a photonic crystal.The sharp transmission peak of electromagnetically induced transparency in photonic crystal generated from a periodic distribution of cold atoms is sensitive to the rotation.Our numerical results show that the sensitivity of relative rotation is about 50 times higher and the sensitivity of absolute rotation is more than two orders higher than that of the traditional resonant optical gyroscope.Also,the sensitivity of the gyroscope can be manipulated by varying the atomic density,modulation frequency,probe pulse width,and photonic crystal length,etc.展开更多
A micro stereo sensor system is proposed for human sensors,where eyes,ears,tongue,nose,body,and brain are applied by six panda rings embedded in a Mach–Zehnder interferometer(MZI).The input power is applied to the up...A micro stereo sensor system is proposed for human sensors,where eyes,ears,tongue,nose,body,and brain are applied by six panda rings embedded in a Mach–Zehnder interferometer(MZI).The input power is applied to the upper branch of MZI and propagates within the system.The six antennas(sensors)are formed by the whispering gallery modes of the panda rings.The space–time modulation signal is applied to the MZI lower branch.The modulated stereo signals can be configured as the plasmon(electron)spin orientations,which can be identified and applied for quantum codes and quantum consciousness.展开更多
Optical biosensors with a high sensitivity and a low detection limit play a highly significant role in extensive scenarios related to our daily life. Combined with a specific numerical simulation based on the transfer...Optical biosensors with a high sensitivity and a low detection limit play a highly significant role in extensive scenarios related to our daily life. Combined with a specific numerical simulation based on the transfer matrix and resonance condition, the idea of novel single-waveguide-based microresonators with a double-spiral-race- track （DSR） shape is proposed and their geometry optimizations and sensing characteristics are also investigated based on the Vernier effect. The devices show good sensing performances, such as a high quality factor of 1.23 x 105, a wide wavelength range of over 120 nm, a high extinction ratio （ER） over 62.1 dB, a high sensitivity of 698.5 nm/RIU, and a low detection limit of 1.8 × 10^-5. Furthermore, single-waveguide-based resonators can also be built by cascading two DSR structures in series, called twin-DSRs, and the results show that the sensing properties are enhanced in terms of quasi free spectral range （FSR） and ER due to the double Vernier effect. Excellent features indicate that our novel single-waveguide-based resonators have the potential for future compact and highly integrated biosensors.展开更多
We present an exact solution to the problem of electromagnetic scattering by nanosphere clusters embedded in a liquid crystal cell, based on the Mie theory. The dependence of the scattering property on the structure p...We present an exact solution to the problem of electromagnetic scattering by nanosphere clusters embedded in a liquid crystal cell, based on the Mie theory. The dependence of the scattering property on the structure parameters is investigated in detail. It is shown that strong transverse light currents at the optical frequency can be obtained from these realized by complex structures. Furthermore, we find that sign reversal of the transverse light current can be changing frequency and voltage. The physical origins of these phenomena have been analyzed. The transverse light current for subwavelength nanoscale dimensions is of practical significance. Thus, the application of these phenomena to optical devices is anticipated.展开更多
We report on the elemental redistribution behavior in oxyfluoride glasses with a high repetition rate nearinfrared femtosecond laser.Elemental analysis by an electro-probe microanalyzer demonstrates that the redistrib...We report on the elemental redistribution behavior in oxyfluoride glasses with a high repetition rate nearinfrared femtosecond laser.Elemental analysis by an electro-probe microanalyzer demonstrates that the redistributions of Ca^2+and Yb^3+ions change dramatically with pulse energy,which are quite different compared with previous reported results.Confocal fluorescence spectra of Yb^3+ions demonstrate that the luminescence intensity changes obviously with the elemental redistribution.The mechanism of the observed phenomenon is discussed.This observation may have potential applications in the fabrication of micro-optical devices.展开更多
基金This work was partially funded by projects 200020-105119/1 and 200021_143501/1 of the Swiss National Science Foundation.
文摘A moireis an interference pattern that appears when two different periodic structures are overlaid.The image created is extremely sensitive to small variations in the original layers and is thus very interesting for anti-counterfeit protection.We present a microfabricated 1D moire enabling complex high-resolution patterns as a significantly improved security feature that cannot be reproduced using standard printing methods.Furthermore,we demonstrate,theoretically and experimentally,that a microscopic deviation from the original design results in a macroscopic variation in the moire that is clearly visible to the naked eye.The record resolution achieved in the elements fabricated and the increased design freedom,make these high-resolution moires excellent candidates for a variety of visually appealing security applications.
基金supported by the National Natural Science Foundation of China(Nos.61827819,61535004,and 61735009)the Guangxi Project(No.AD17195074)the National Defense Pre-Research Foundation of China(No.6140414030102)
文摘By using a specialty optical fiber, a series of powerful microparticle manipulation tools, including optical tweezers, a micro-optical hand, and an optical gun, are developed and demonstrated. In this paper,a review of our research activities on the optical manipulation of microparticles is presented. In particular,we will describe a kind of specialty optical fiber designed and fabricated for building optical trapping and manipulating tools. The performances of annular core fiber-based optical tweezers, a multicore fiber-based micro-optical hand, and a coaxial dual waveguide fiber-based optical gun are demonstrated as examples of applications and discussed in detail. The fiber can be used in cell manipulation in life science and drug response in medicine.
基金This work was funded by the German Science Foundation within the framework of the Priority Program 1337 Aktive MikrooptikThe authors thank Philipp Muller and the Laboratory for Biomedical Technology at IMTEK for coating the master lenses.
文摘Microlenses fabricated using flexible elastomers can be tuned in focal length by application of controlled strain.By varying the strain azimuthally,the lenses may be deformed asymmetrically such that aberrations may be controlled.This approach is used to tune the astigmatism of the tunable lenses,and it is shown that the generated wavefront may be accurately controlled.The lens presented here has an initial focal length of 32.6 mm and a tuning range of 12.3 mm for approximately 10%applied strain.The range of directly tunable Zernike polynomials representing astigmatism is about 3 mm,while the secondary lens errors,which cannot be tuned directly,vary only by about 0.2 mm.
基金supported by 973 Program of China under Grant No.2006CB302900part by the National Natural Science Foundation of China under Grant No.60825405 and No.60778018
文摘Several approaches to fabricate micro optical elements by use of half tone masks are studied and compared. It is shown that half tone masks employed in filtering image systems can obtain gray patterns with considerably high precision, but it is hard to operate from the viewpoint of operation. The method using contacting lithography technology or laser ablation can be easily operated with the cost of reducing fabrication precision and the trouble of choosing appropriate materials. For all of these methods, the coding of half tone masks with corrections for the nonlinear characteristics of coding, imaging and photoresist is recommended.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11804066 and 61773133)Heilongjiang Provincial Natural Science Foundation of China(Grant No.LH2019A005)+1 种基金China Postdoctoral Science Foundation(Grant No.2018M630337)Heilongjiang Provincial Postdoctoral Science Foundation(Grant No.LBHZ18062)。
文摘We propose a core rotation-sensing element for improving the sensitivity of the micro-optical gyroscope using the large nonreciprocal effect with a photonic crystal.The sharp transmission peak of electromagnetically induced transparency in photonic crystal generated from a periodic distribution of cold atoms is sensitive to the rotation.Our numerical results show that the sensitivity of relative rotation is about 50 times higher and the sensitivity of absolute rotation is more than two orders higher than that of the traditional resonant optical gyroscope.Also,the sensitivity of the gyroscope can be manipulated by varying the atomic density,modulation frequency,probe pulse width,and photonic crystal length,etc.
文摘A micro stereo sensor system is proposed for human sensors,where eyes,ears,tongue,nose,body,and brain are applied by six panda rings embedded in a Mach–Zehnder interferometer(MZI).The input power is applied to the upper branch of MZI and propagates within the system.The six antennas(sensors)are formed by the whispering gallery modes of the panda rings.The space–time modulation signal is applied to the MZI lower branch.The modulated stereo signals can be configured as the plasmon(electron)spin orientations,which can be identified and applied for quantum codes and quantum consciousness.
基金supported in part by the National Natural Science Foundation of China(No.61575038)the Fundamental Research Funds for the Central Universities(No.ZYGX2015J052)
文摘Optical biosensors with a high sensitivity and a low detection limit play a highly significant role in extensive scenarios related to our daily life. Combined with a specific numerical simulation based on the transfer matrix and resonance condition, the idea of novel single-waveguide-based microresonators with a double-spiral-race- track （DSR） shape is proposed and their geometry optimizations and sensing characteristics are also investigated based on the Vernier effect. The devices show good sensing performances, such as a high quality factor of 1.23 x 105, a wide wavelength range of over 120 nm, a high extinction ratio （ER） over 62.1 dB, a high sensitivity of 698.5 nm/RIU, and a low detection limit of 1.8 × 10^-5. Furthermore, single-waveguide-based resonators can also be built by cascading two DSR structures in series, called twin-DSRs, and the results show that the sensing properties are enhanced in terms of quasi free spectral range （FSR） and ER due to the double Vernier effect. Excellent features indicate that our novel single-waveguide-based resonators have the potential for future compact and highly integrated biosensors.
基金National Key R&D Program of China(2017YFA0303800)National Natural Science Foundation of China(NSFC)(11574031,61421001)
文摘We present an exact solution to the problem of electromagnetic scattering by nanosphere clusters embedded in a liquid crystal cell, based on the Mie theory. The dependence of the scattering property on the structure parameters is investigated in detail. It is shown that strong transverse light currents at the optical frequency can be obtained from these realized by complex structures. Furthermore, we find that sign reversal of the transverse light current can be changing frequency and voltage. The physical origins of these phenomena have been analyzed. The transverse light current for subwavelength nanoscale dimensions is of practical significance. Thus, the application of these phenomena to optical devices is anticipated.
文摘We report on the elemental redistribution behavior in oxyfluoride glasses with a high repetition rate nearinfrared femtosecond laser.Elemental analysis by an electro-probe microanalyzer demonstrates that the redistributions of Ca^2+and Yb^3+ions change dramatically with pulse energy,which are quite different compared with previous reported results.Confocal fluorescence spectra of Yb^3+ions demonstrate that the luminescence intensity changes obviously with the elemental redistribution.The mechanism of the observed phenomenon is discussed.This observation may have potential applications in the fabrication of micro-optical devices.
