{"id":220,"date":"2013-09-24T19:05:01","date_gmt":"2013-09-24T23:05:01","guid":{"rendered":"http:\/\/optomech.wpi.edu\/?page_id=220"},"modified":"2013-09-26T12:38:18","modified_gmt":"2013-09-26T16:38:18","slug":"research-fiber-optical-tweezers","status":"publish","type":"page","link":"https:\/\/optomech.wpi.edu\/?page_id=220","title":{"rendered":"Fiber Optical Tweezers"},"content":{"rendered":"<p><span style=\"text-decoration: underline;\"><i style=\"color: #0000ff; font-family: verdana, sans-serif; font-size: 13px;\"><i style=\"color: #0000ff; font-family: verdana, sans-serif; font-size: 13px;\"><b><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-234 alignright\" alt=\"Why\" src=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/Why-739x1024.jpg\" width=\"252\" height=\"349\" srcset=\"https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/Why-739x1024.jpg 739w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/Why-216x300.jpg 216w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/Why.jpg 1326w\" sizes=\"(max-width: 252px) 100vw, 252px\" \/><\/b><\/i><b>Goal<\/b><\/i><\/span><\/p>\n<p>To enhance the understanding, discover new phenomena, and explore potential applications fiber optical trapping system.<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"color: #0000ff;\"><b><i><span style=\"text-decoration: underline;\">Why Fiber Optical Tweezers<\/span><\/i><\/b><\/span><\/p>\n<ul>\n<li>Conventional optical tweezers (OTs) require an high NA objective lens to build up the trap(s), which is bulky, expensive, and have many restrictions such\u00a0as working distances and compatible substrates.<\/li>\n<li>Fiber optical tweezers have small footprints, are integratable, and can flexibly move anywhere inside the medium. The system works as a miniature &#8220;probe&#8221;, compared with conventional optical tweezers as a large &#8220;platform&#8221;.<\/li>\n<li>Fiber optical tweezers don&#8217;t have any requirements on the substrate materials or thickness.<\/li>\n<\/ul>\n<p><span style=\"text-decoration: underline; color: #0000ff;\"><b><i>Why is our research important<\/i><\/b><\/span><\/p>\n<ul>\n<li>Common fiber based optical trapping systems, namely single-fiber OTs and counter-propagating OTs, suffer from diffiiculty of creating 3D traps and poor flexibility, respectively.<\/li>\n<li>The inclined DFOTs [1], which have a flexible system setup and readily achievable 3D trapping capability, have not been systematically studied before. We carried out the first experimental calibration of the optical forces in this system, enabling it to measure forces.<\/li>\n<li>Multiple functionalities were achieved with the DFOTs for the first time, making it potential for parallel manipulation and interaction force investigation.<\/li>\n<li>Fiber optical tweezers suffer from weak focusing of the light and hence low trapping efficiency, which is a majoy drawback compared with conventional optical tweezers. We achieved superfocusing on the fiber tip and a trapping efficiency comparable with that of conventional optical tweezers, without using a high-NA objective lens.<\/li>\n<\/ul>\n<h2><span style=\"text size: 2.5; color: #ff0000;\">System 1: Dual Fiber Optical Tweezers<\/span><\/h2>\n<p><span style=\"font-family: verdana, sans-serif;\"><span style=\"text-decoration: underline;\"><i><b><span style=\"color: #0000ff;\">Ho<\/span><\/b><\/i><\/span><\/span><span style=\"font-family: verdana, sans-serif;\"><span style=\"text-decoration: underline;\"><i><b><span style=\"color: #0000ff;\">w does it wo<\/span><\/b><\/i><\/span><\/span><span style=\"font-family: verdana, sans-serif;\"><span style=\"text-decoration: underline;\"><i><b><span style=\"color: #0000ff;\">rk<\/span><\/b><\/i><\/span><\/span><\/p>\n<ul>\n<li>A<img loading=\"lazy\" decoding=\"async\" class=\" wp-image-238 alignright\" alt=\"How\" src=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/How-300x273.jpg\" width=\"180\" height=\"164\" srcset=\"https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/How-300x273.jpg 300w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/How.jpg 916w\" sizes=\"(max-width: 180px) 100vw, 180px\" \/>\u00a0stable 3D trap (Bead 2) is enabled by balancing four force components (two scattering and two gradient) without the requirement of strong focusing.<\/li>\n<li>Two 2D traps (1 and 3), are enabled by individual weakly focused optical beams.<\/li>\n<li><span style=\"font-size: 13px;\">The separation of the traps can be tuned by changing the height of the block, enabling novel and promising functionalities.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #0000ff;\"><span style=\"text-decoration: underline;\"><i><b>What was achieved<\/b><\/i><\/span><\/span><\/p>\n<p><span style=\"color: #000000; font-family: 'Times New Roman';\">1. Investigation of the 3D trap\u00a0<\/span><span style=\"font-family: 'times new roman', serif;\">[2]<\/span><\/p>\n<ul>\n<li>Experimental calibration of the 3D trap was carried out with two methods: drag force method and power spectrum analysis.<\/li>\n<li>The parametric study of the 3D trap was studied based on our modeling. The simulation results match with those obtained in the experiments.<\/li>\n<li>Simulations reveal that the inclined DFOTs are more robust to the fiber misalignment when compared with the counter-propagating DFOTs.<\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><span style=\"font-family: 'times new roman', serif;\">2. Discovery of multiple traps and functionalities\u00a0<\/span><\/span><span style=\"font-family: 'times new roman', serif;\">[3]<\/span><\/p>\n<ul>\n<li><a href=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/mult_traps_3.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-247 alignright\" alt=\"mult_traps_3\" src=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/mult_traps_3-1024x434.jpg\" width=\"420\" height=\"178\" srcset=\"https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/mult_traps_3-1024x434.jpg 1024w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/mult_traps_3-300x127.jpg 300w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/mult_traps_3.jpg 1250w\" sizes=\"(max-width: 420px) 100vw, 420px\" \/><\/a>Multiple traps are discovered in experiments and studied both experimentally and numerically.<\/li>\n<li>Multiple functionalities, including bead separation, bead grouping, and bead stacking both in 2D and 3D, were demonstrated in the experiment.<\/li>\n<li>The functionalities was understood with our modeling results of the optical force field.<\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><span style=\"font-family: 'times new roman', serif;\">3. Manipulation of micro-rods<\/span><\/span><span style=\"font-family: 'times new roman', serif;\">\u00a0[4]<\/span><\/p>\n<ul>\n<li><a href=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/rods-2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-250 alignright\" alt=\"rods 2\" src=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/rods-2.jpg\" width=\"384\" height=\"254\" srcset=\"https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/rods-2.jpg 800w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/rods-2-300x198.jpg 300w\" sizes=\"(max-width: 384px) 100vw, 384px\" \/><\/a>Compared with beads, micro-rods provide additional degrees of freedom to control, and hence more functionalities are achievable with the inclined DFOTs.<\/li>\n<li>Rod trapping, alignment, stacking, rotation, and binding were experimentally demonstrated.<\/li>\n<li>Modeling of the optical force and torque fields improves the understanding of these functionalities and help design the system to obtain desired ones.<\/li>\n<\/ul>\n<p align=\"left\"><span style=\"color: #0000ff;\"><b><i><span style=\"text-decoration: underline;\"><span style=\"font-family: verdana, sans-serif;\">So what?<\/span><\/span><\/i><\/b><\/span><\/p>\n<ul>\n<li><span style=\"color: #008800; font-family: 'Times New Roman';\"><b>Flexibility and integrability<\/b>:\u00a0<span style=\"color: #000000;\">the inclined DFOTs can be used as a system block and can be readily integrated, which enables it to find new applications in Lab-on-a-chip systems.<\/span><\/span><\/li>\n<li><span style=\"color: #ff8800; font-family: 'Times New Roman';\"><b>Capability as a force sensor:<\/b><span style=\"color: #000000;\">\u00a0trapping stiffness was obtained in the experiments, for the first time, which enables the inclined DFOTs to be used in force sensing in addition to particle manipulation.<\/span><\/span><\/li>\n<li><span style=\"color: #008800; font-family: 'Times New Roman';\"><span style=\"color: #993300;\"><b>System design based on specific requirements.<\/b><\/span><span style=\"color: #000000;\">\u00a0The enhanced understanding of the inclined DFOTs provides suggestions on how to design the system to better fulfill the desired functions.<\/span><\/span><\/li>\n<li><span style=\"color: #ff0000; font-family: 'Times New Roman';\"><b>Manipulation of irregularly shaped particles:<\/b><span style=\"color: #000000;\">\u00a0the multiple traps facilitate complex functionalities to be realized with both spherical and cylindrical particles in on-chip systems<span style=\"font-family: sans-serif;\">.<\/span><\/span><\/span><\/li>\n<li><span style=\"color: #ff0000; font-family: 'Times New Roman';\"><span style=\"color: #800080;\"><b>Distributed force applied on the cell membrane:<\/b><\/span><span style=\"color: #000000;\">\u00a0possible for cell mechanical property measurement by stretching the cell without physical contact<span style=\"font-family: sans-serif;\">.<\/span><\/span><\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h2><span style=\"color: #ff0000;\">System 2: Fiber Based Surface Plasmonic Lens<\/span><\/h2>\n<p><span style=\"text-decoration: underline;\"><span style=\"color: #0000ff; text-decoration: underline;\"><i><b>Ho<\/b><\/i><i><b>w does it wo<\/b><\/i><i><b>rk<\/b><\/i><\/span><\/span><\/p>\n<p><span style=\"text-decoration: underline;\"><span style=\"color: #0000ff; text-decoration: underline;\"><i><b><a href=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/SP-principle-3_f2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-261 alignright\" alt=\"SP principle 3_f2\" src=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/SP-principle-3_f2.jpg\" width=\"240\" height=\"152\" srcset=\"https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/SP-principle-3_f2.jpg 400w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/SP-principle-3_f2-300x189.jpg 300w\" sizes=\"(max-width: 240px) 100vw, 240px\" \/><\/a><\/b><\/i><\/span><\/span><\/p>\n<ul>\n<li><span style=\"color: #000000; font-family: 'times new roman', serif; font-size: 13px;\">The SP lens, fabricated directly on a fiber endface, is composed of a set of nanoscale concentric slits.<\/span><\/li>\n<li><span style=\"color: #000000; font-family: 'times new roman', serif; font-size: 13px;\">The superfocusing is achieve by converting the planar wave front (in optical fiber) to a spherical one (in the medium).<\/span><\/li>\n<li><span style=\"color: #000000; font-family: 'times new roman', serif; font-size: 13px;\">The concentric slits serves as waveguides of the surface plasmon polaritons (SPPs) that introduce desired phase delays to the SPPs propagating inside.<\/span><\/li>\n<\/ul>\n<p><b><i><span style=\"text-decoration: underline;\"><span style=\"color: #0000ff;\">What was achieved<\/span><\/span><\/i><\/b><\/p>\n<p><span style=\"color: #000000;\">\u00a0 \u00a0 1. Experimental i<\/span><span style=\"color: #000000;\">ntensity profile demonstrating superfocusing on top of regular\u00a0<\/span><b style=\"font-size: 13px;\"><span style=\"color: #000000;\">single-mode optical fibers<\/span><\/b><span style=\"color: #000000;\">. [5]<\/span><\/p>\n<ul>\n<li><span style=\"font-size: 13px;\">Two SP lenses, one 3-ring and one 4-ring, were fabricated on fiber tips and tested.<\/span><\/li>\n<li><span style=\"color: #000000;\">The spot sizes (FWHM&#8217;s) of both samples\u00a0<\/span><b style=\"font-size: 13px;\"><span style=\"color: #000000;\">reach the diffraction limit<\/span><\/b><span style=\"color: #000000;\">\u00a0of 0.51*wavelength \/ NA at the wavelength of 808 nm.<\/span><\/li>\n<li><span style=\"color: #000000; font-size: 13px;\">The 3-ring SP lens achieved a focal size comparable with that of a high NA objective lens (~330 nm for NA=1.25).<\/span><\/li>\n<li><span style=\"color: #000000; font-size: 13px;\">The transmission of the optical power is over 70% (normalized to the power incident on the slit openings) for both samples.<\/span><\/li>\n<\/ul>\n<p><a href=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/4ringIntensity8_2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-262\" alt=\"4ringIntensity8_2\" src=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/4ringIntensity8_2.jpg\" width=\"213\" height=\"318\" srcset=\"https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/4ringIntensity8_2.jpg 213w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/4ringIntensity8_2-200x300.jpg 200w\" sizes=\"(max-width: 213px) 100vw, 213px\" \/>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0<\/a><a href=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/3ring-Intensity-8.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-263\" alt=\"3ring Intensity 8\" src=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/3ring-Intensity-8.jpg\" width=\"310\" height=\"318\" srcset=\"https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/3ring-Intensity-8.jpg 310w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/3ring-Intensity-8-292x300.jpg 292w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/3ring-Intensity-8-50x50.jpg 50w\" sizes=\"(max-width: 310px) 100vw, 310px\" \/><\/a><\/p>\n<p align=\"left\"><span style=\"color: #000000;\">\u00a0 \u00a02.\u00a0<b>3D trapping\u00a0<\/b>of sub-micron-size particles. [6]<br \/>\n<\/span><\/p>\n<ul>\n<li><span style=\"color: #000000;\">As one of the potential applications of the fiber-based SP lens, we have achieved\u00a0<\/span><b style=\"font-size: 13px;\"><span style=\"color: #000000;\">3D trapping<\/span><\/b><span style=\"color: #000000;\">\u00a0of a 500-nm fluorescent polystyrene bead (in the lower left figure) and a sub-micron-size bacterium (in the lower right figure).<\/span><\/li>\n<li><span style=\"color: #000000; font-size: 13px;\">&#8220;R&#8221; and &#8220;T&#8221; in the figures below designate reference particles (fixed to the substrate) and trapped particles (moving with the fiber), respectively. The text and arrows in the lower right corner of each picture specify the object to move and the direction to move along in the next step.<\/span><\/li>\n<li><span style=\"color: #000000; font-size: 13px;\">The 3D trapping was achieved with a power of ~1 mW out of optical fiber, which is much lower than those used by conventional optical tweezers, so the trapped samples suffered less from heating and photodamage.<\/span><\/li>\n<\/ul>\n<p><a href=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/500NmTrapping2.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-269\" alt=\"500NmTrapping2\" src=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/500NmTrapping2-300x248.jpg\" width=\"300\" height=\"248\" srcset=\"https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/500NmTrapping2-300x248.jpg 300w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/500NmTrapping2-1024x849.jpg 1024w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/500NmTrapping2.jpg 1206w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a>\u00a0 \u00a0<img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-270\" alt=\"BacTrap_2\" src=\"http:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/BacTrap_2-300x243.jpg\" width=\"300\" height=\"243\" srcset=\"https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/BacTrap_2-300x243.jpg 300w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/BacTrap_2-1024x831.jpg 1024w, https:\/\/optomech.wpi.edu\/wp-content\/uploads\/2013\/09\/BacTrap_2.jpg 1232w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<p><span style=\"font-family: verdana, sans-serif;\"><b><i><span style=\"text-decoration: underline;\"><span style=\"color: #0000ff;\">So what<\/span><\/span><\/i><\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-family: 'times new roman', serif;\"><span style=\"color: #ff0000;\">Superfocusing\u00a0<\/span><span style=\"color: #000000;\">achieved on top of a regular optical fiber : bridge the optical power and signals between nanoscale systems and conventional optical devices.<\/span><\/span><\/li>\n<li><span style=\"font-family: 'times new roman', serif;\"><span style=\"color: #38761d;\">Flexible setup<\/span><span style=\"color: #ff9900;\">\u00a0<\/span><span style=\"color: #000000;\">with little disturbance induced by environmental noise.<\/span><\/span><\/li>\n<li><span style=\"font-family: 'times new roman', serif;\"><span style=\"color: #cc0000;\"><span style=\"color: #ff00ff;\">Significantly enhanced trapping strength<\/span>\u00a0<\/span><span style=\"color: #000000;\">by the SP lens compared with the lensed fibers used in the inclined DFOTs: 3D trapping of sub-micron-sized particles was enabled at a power lower than those of the conventional optical tweezers.<\/span><\/span><\/li>\n<li><span style=\"font-family: 'times new roman', serif;\"><span style=\"color: #0000ff;\">Potential applications :\u00a0<\/span><span style=\"color: #000000;\">power delivery for nanophotonic systems, super-resolution laser writing, and high-resolution fluorescence detection, in addition to optical trapping.<\/span><\/span><\/li>\n<\/ul>\n<p align=\"left\"><b><span style=\"color: #000000; font-family: 'Times New Roman'; font-size: medium;\">References<\/span><\/b><\/p>\n<p align=\"left\"><span style=\"color: #000000; font-family: 'Times New Roman';\">[1] K. Taguchi, K. Atsuta, T. Nakata and M. Ideda, &#8220;Levitation of a microscopic object using plural optical fibers,&#8221;\u00a0<i>Opt. Commun<\/i>.\u00a0<b>176<\/b>, 43 (2000).<\/span><\/p>\n<p align=\"left\"><span style=\"color: #000000; font-family: 'Times New Roman';\">[2] Yuxiang Liu and Miao Yu, &#8220;Investigation of inclined dual-fiber optical tweezers for 3D manipulation and force sensing,&#8221;\u00a0<i>Opt. Express<\/i>,\u00a0<b>17<\/b>\u00a013624-13638 (2009). (Selected for publication in the\u00a0<i>Virtual Journal for Biomedical Optics<\/i>, Editor: Gregory W. Faris, Vol. 4, Iss. 10, Oct. 2, 2009) [<span style=\"color: #0000ff;\"><a href=\"http:\/\/www.opticsinfobase.org\/oe\/abstract.cfm?uri=oe-17-16-13624\" target=\"_blank\" rel=\"nofollow\"><span style=\"text-decoration: underline;\">Crossref<\/span><\/a><\/span>]<\/span><\/p>\n<p align=\"left\"><span style=\"color: #000000; font-family: 'Times New Roman';\">[3] Yuxiang Liu and Miao Yu, &#8220;Multiple traps created with an inclined dual-fiber system,&#8221; Opt. Express\u00a0<b>17<\/b>, 21680-21690 (2009). (Selected for publication in the\u00a0<i>Virtual Journal for Biomedical Optics<\/i>, Editor: Gregory W. Faris, Vol. 4, Iss. 13, Dec. 2, 2009) [<span style=\"color: #0000ff;\"><a href=\"http:\/\/www.opticsinfobase.org\/oe\/abstract.cfm?uri=oe-17-24-21680\" target=\"_blank\" rel=\"nofollow\"><span style=\"text-decoration: underline;\">Crossref<\/span><\/a><\/span>]<\/span><\/p>\n<p align=\"left\"><span style=\"color: #000000; font-family: 'Times New Roman';\">[4] Yuxiang Liu and Miao Yu, &#8220;Optical Manipulation and Binding of Microrods with Multiple Traps Enabled in an Inclined Dual-fiber System,&#8221;<i>Biomicrofluidics<\/i>\u00a0<b>4<\/b>, 043010 (2010). [<a href=\"http:\/\/bmf.aip.org\/resource\/1\/biomgb\/v4\/i4\/p043010_s1\" target=\"_blank\" rel=\"nofollow\">Crossref<\/a>]<\/span><\/p>\n<p align=\"left\"><span style=\"color: #000000; font-family: 'Times New Roman';\">[5]\u00a0Yuxiang Liu, Hua Xu, Felix Stief, Nikolai Zhitenev, and Miao Yu, &#8220;Far-field superfocusing with an optical fiber based surface plasmonic lens made of nanoscale concentric annular slits,&#8221; <em>Opt. Express<\/em> 19, 20233-20243 (2011).<\/span><\/p>\n<p align=\"left\"><span style=\"color: #000000; font-family: 'Times New Roman';\">[6]\u00a0Yuxiang Liu, Felix Stief, and Miao Yu, \u201cSubwavelength optical trapping with a fiber-based\u00a0surface plasmonic lens,\u201d <em>Opt. Lett.<\/em> 38, 721-723 (2013).<\/span><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Goal To enhance the understanding, discover new phenomena, and explore potential applications fiber optical trapping system. &nbsp; Why Fiber Optical Tweezers Conventional optical tweezers (OTs) require an high NA objective lens to build up the trap(s), which is bulky, expensive, and have many restrictions such\u00a0as working distances and compatible substrates. Fiber optical tweezers have small&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-templates\/template-full-width.php","meta":{"footnotes":""},"_links":{"self":[{"href":"https:\/\/optomech.wpi.edu\/index.php?rest_route=\/wp\/v2\/pages\/220"}],"collection":[{"href":"https:\/\/optomech.wpi.edu\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/optomech.wpi.edu\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/optomech.wpi.edu\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/optomech.wpi.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=220"}],"version-history":[{"count":32,"href":"https:\/\/optomech.wpi.edu\/index.php?rest_route=\/wp\/v2\/pages\/220\/revisions"}],"predecessor-version":[{"id":290,"href":"https:\/\/optomech.wpi.edu\/index.php?rest_route=\/wp\/v2\/pages\/220\/revisions\/290"}],"wp:attachment":[{"href":"https:\/\/optomech.wpi.edu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=220"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}