{"title":"Accurate Calibration of Optical Tweezers close to a glass surface using interference rings in backscattered light","authors":"N. Westbrook","doi":"10.1051/jeos/2023026","DOIUrl":null,"url":null,"abstract":"Detecting the retro-reflected trap beam is a convenient way to measure forces applied by optical tweezers on biological systems, leaving free top access to the sample and making it easier to combine with fluorescence and phase contrast imaging. Doing so in the back focal plane of the microscope objective makes the calibration insensitive to the joint displacement of the trap and bead. Here, in addition, we take advantage of the very well contrasted interference rings observed in this specific plane to extract with good accuracy the height of the trapped bead. We thus map the viscous drag dependence close to the surface and reach an agreement between four calibration techniques, on an accurate value of the trap stiffness down to 2 micron distance to the surface and up to 600 mW of laser power. Combining this detection scheme with phase contrast microscopy, we show that the phase ring in the back focal plane of the objective overlaps with the interference rings and must be deported in a conjugate plane on the imaging path.","PeriodicalId":674,"journal":{"name":"Journal of the European Optical Society-Rapid Publications","volume":" ","pages":""},"PeriodicalIF":1.9000,"publicationDate":"2023-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of the European Optical Society-Rapid Publications","FirstCategoryId":"4","ListUrlMain":"https://doi.org/10.1051/jeos/2023026","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"OPTICS","Score":null,"Total":0}
引用次数: 0
Abstract
Detecting the retro-reflected trap beam is a convenient way to measure forces applied by optical tweezers on biological systems, leaving free top access to the sample and making it easier to combine with fluorescence and phase contrast imaging. Doing so in the back focal plane of the microscope objective makes the calibration insensitive to the joint displacement of the trap and bead. Here, in addition, we take advantage of the very well contrasted interference rings observed in this specific plane to extract with good accuracy the height of the trapped bead. We thus map the viscous drag dependence close to the surface and reach an agreement between four calibration techniques, on an accurate value of the trap stiffness down to 2 micron distance to the surface and up to 600 mW of laser power. Combining this detection scheme with phase contrast microscopy, we show that the phase ring in the back focal plane of the objective overlaps with the interference rings and must be deported in a conjugate plane on the imaging path.
期刊介绍:
Rapid progress in optics and photonics has broadened its application enormously into many branches, including information and communication technology, security, sensing, bio- and medical sciences, healthcare and chemistry.
Recent achievements in other sciences have allowed continual discovery of new natural mysteries and formulation of challenging goals for optics that require further development of modern concepts and running fundamental research.
The Journal of the European Optical Society – Rapid Publications (JEOS:RP) aims to tackle all of the aforementioned points in the form of prompt, scientific, high-quality communications that report on the latest findings. It presents emerging technologies and outlining strategic goals in optics and photonics.
The journal covers both fundamental and applied topics, including but not limited to:
Classical and quantum optics
Light/matter interaction
Optical communication
Micro- and nanooptics
Nonlinear optical phenomena
Optical materials
Optical metrology
Optical spectroscopy
Colour research
Nano and metamaterials
Modern photonics technology
Optical engineering, design and instrumentation
Optical applications in bio-physics and medicine
Interdisciplinary fields using photonics, such as in energy, climate change and cultural heritage
The journal aims to provide readers with recent and important achievements in optics/photonics and, as its name suggests, it strives for the shortest possible publication time.