Optical frequency division(OFD)produces low-noise microwave and millimeter-wave(mmWave)signals by transferring the exceptional stability of optical references to electronic frequency domains.Recent developments in int...Optical frequency division(OFD)produces low-noise microwave and millimeter-wave(mmWave)signals by transferring the exceptional stability of optical references to electronic frequency domains.Recent developments in integrated optical references and soliton microcombs have paved the way for miniaturizing OFD oscillators to chip scale.Critical to this realization is a rapid tunable frequency comb that is stabilized to the optical references,thereby coherently linking optical and electronic frequencies.In this work,we advance the on-chip OFD technology using an integrated high-speed lead zirconate titanate(PZT)stress-optic actuator on the SiN soliton microcomb resonator.The integrated PZT actuator tunes the resonance frequency of the soliton-generating microresonator with a bandwidth exceeding 10s MHz and thus adjusts the soliton repetition rate.Optical frequency division and low-noise mmWave generation are demonstrated by feedback control of the soliton repetition rate through the integrated PZT-actuator,and the soliton microcomb is stabilized to a pair of reference lasers that are locked to an integrated 4 m SiN coil reference cavity.Our approach provides a fast,versatile,and integrated control mechanism for OFD oscillators and their applications in advanced communications,sensing,and precise timing.展开更多
Multiple reference optical coherence tomography（MR-OCT） is a recently developed, low-cost and compact time-domain OCT solution for primary care and consumer level applications. A combination of a voice coil actuator...Multiple reference optical coherence tomography（MR-OCT） is a recently developed, low-cost and compact time-domain OCT solution for primary care and consumer level applications. A combination of a voice coil actuator and a partial mirror（PM） extends the scan range for imaging depths of approximately 1 mm in biological samples. Our previous research on MR-OCT is based only on intensity information obtained from the depth-resolved interference signal. In this Letter, we extract the phase information from the MR-OCT signal and, hence, provide an additional contrast modality. The phase sensitivity of the system is measured to be approximately 0.2 and 1.5 rad for the first and twelfth orders of reflection when using a mirror as the sample.This Letter describes first results of phase-sensitive data measured on a phantom obtained with MR-OCT. Data from a chick embryo chorioallantoic membrane（CAM） is used to demonstrate the feasibility of MR-OCT for in vivo phase-sensitive imaging.展开更多
On the basis of analysis on the temperature monitoring methods for high voltage devices, a new type of fiber optic sensor structure with reference channel is given. And the operation principle of fiber optic sensor is...On the basis of analysis on the temperature monitoring methods for high voltage devices, a new type of fiber optic sensor structure with reference channel is given. And the operation principle of fiber optic sensor is analysed at large based on the absorption of semiconductor chip. The mathematical model of both devices and the whole system are also given. It is proved by the experiment that this mathematical model is reliable.展开更多
The objective of this study is to demonstrate that tensile stress resulting due to applied force on cornea can be accurately measured by using a time-domain common-path optical coherence tomography （OCT） system with...The objective of this study is to demonstrate that tensile stress resulting due to applied force on cornea can be accurately measured by using a time-domain common-path optical coherence tomography （OCT） system with an external contact reference. The unique design of the common-path OCT is utilized to set up an imaging system in which a chicken eye is placed adjacent to a glass plate serving as the external reference plane for the imaging system. As the force is applied to the chicken eye, it presses against the reference glass plate. The modified OCT image obtained is used to calculate the size of contact area, which is then used to derive the tensile stress on the cornea. The drop in signal levels upon contact of reference glass plate with the tissue are extremely sharp because of the sharp decline in reference power levels itself, thus providing us with an accurate measurement of contact area. The experimental results were in good agreement with the numerical predictions. The results of this study might be useful in providing new insights and ideas to improve the precision and safety of currently used ophthalmic surgical techniques. This research outlines a method which could be used to provide high resolution OCT images and a precise feedback of the forces applied to the cornea simultaneously.展开更多
Dear Editor,We report a rare case of bilateral central vision loss and color vision abnormalities after actinomycin D chemotherapy for a hydatidiform mole.Toxic optic neuropathy(TON)refers to a spectrum of disorders c...Dear Editor,We report a rare case of bilateral central vision loss and color vision abnormalities after actinomycin D chemotherapy for a hydatidiform mole.Toxic optic neuropathy(TON)refers to a spectrum of disorders characterized by bilateral visual loss,papillomacular bundle damage,central or cecocentral scotoma,and color vision abnormalities[1].展开更多
基金Defense Advanced Research Projects Agency(HR0011-22-2-0008,N660012424000)National Science Foundation(2023775)。
文摘Optical frequency division(OFD)produces low-noise microwave and millimeter-wave(mmWave)signals by transferring the exceptional stability of optical references to electronic frequency domains.Recent developments in integrated optical references and soliton microcombs have paved the way for miniaturizing OFD oscillators to chip scale.Critical to this realization is a rapid tunable frequency comb that is stabilized to the optical references,thereby coherently linking optical and electronic frequencies.In this work,we advance the on-chip OFD technology using an integrated high-speed lead zirconate titanate(PZT)stress-optic actuator on the SiN soliton microcomb resonator.The integrated PZT actuator tunes the resonance frequency of the soliton-generating microresonator with a bandwidth exceeding 10s MHz and thus adjusts the soliton repetition rate.Optical frequency division and low-noise mmWave generation are demonstrated by feedback control of the soliton repetition rate through the integrated PZT-actuator,and the soliton microcomb is stabilized to a pair of reference lasers that are locked to an integrated 4 m SiN coil reference cavity.Our approach provides a fast,versatile,and integrated control mechanism for OFD oscillators and their applications in advanced communications,sensing,and precise timing.
基金supported by the Galway University Foundationthe University of Limerick Foundationthe National Biophotonics Imaging Platform(NBIP)Ireland,funded under the Higher Education Authority PRTLI Cycle 4,co-funded by the Irish Government and the European Union Investing in your future,and Compact Imaging,Inc
文摘Multiple reference optical coherence tomography（MR-OCT） is a recently developed, low-cost and compact time-domain OCT solution for primary care and consumer level applications. A combination of a voice coil actuator and a partial mirror（PM） extends the scan range for imaging depths of approximately 1 mm in biological samples. Our previous research on MR-OCT is based only on intensity information obtained from the depth-resolved interference signal. In this Letter, we extract the phase information from the MR-OCT signal and, hence, provide an additional contrast modality. The phase sensitivity of the system is measured to be approximately 0.2 and 1.5 rad for the first and twelfth orders of reflection when using a mirror as the sample.This Letter describes first results of phase-sensitive data measured on a phantom obtained with MR-OCT. Data from a chick embryo chorioallantoic membrane（CAM） is used to demonstrate the feasibility of MR-OCT for in vivo phase-sensitive imaging.
文摘On the basis of analysis on the temperature monitoring methods for high voltage devices, a new type of fiber optic sensor structure with reference channel is given. And the operation principle of fiber optic sensor is analysed at large based on the absorption of semiconductor chip. The mathematical model of both devices and the whole system are also given. It is proved by the experiment that this mathematical model is reliable.
文摘The objective of this study is to demonstrate that tensile stress resulting due to applied force on cornea can be accurately measured by using a time-domain common-path optical coherence tomography （OCT） system with an external contact reference. The unique design of the common-path OCT is utilized to set up an imaging system in which a chicken eye is placed adjacent to a glass plate serving as the external reference plane for the imaging system. As the force is applied to the chicken eye, it presses against the reference glass plate. The modified OCT image obtained is used to calculate the size of contact area, which is then used to derive the tensile stress on the cornea. The drop in signal levels upon contact of reference glass plate with the tissue are extremely sharp because of the sharp decline in reference power levels itself, thus providing us with an accurate measurement of contact area. The experimental results were in good agreement with the numerical predictions. The results of this study might be useful in providing new insights and ideas to improve the precision and safety of currently used ophthalmic surgical techniques. This research outlines a method which could be used to provide high resolution OCT images and a precise feedback of the forces applied to the cornea simultaneously.
基金Supported by the Shanghai“Rising Stars of Medical Talents”Youth Development Program[No.SHWSRS(2023)_62]the Specialized Clinical Research Program of Shanghai Municipal Health Commission(No.20235Y0027)+1 种基金the Youth Project of the National Natural Science Fund(No.82000918)the Shanghai Sailing Program(No.20YF1404800).
文摘Dear Editor,We report a rare case of bilateral central vision loss and color vision abnormalities after actinomycin D chemotherapy for a hydatidiform mole.Toxic optic neuropathy(TON)refers to a spectrum of disorders characterized by bilateral visual loss,papillomacular bundle damage,central or cecocentral scotoma,and color vision abnormalities[1].
