1 / 20

Optical Tweezers

Optical Tweezers. Team : Maryam Badakhshi , Shannon O’Keefe, Laura Poloni , Hasmita Singh. Overview. 1) Introduction 2) Background & Applications 3) Apparatus 4) Laser Safety. 1. Introduction. Experiment Context --Presentation.

abiola
Download Presentation

Optical Tweezers

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Optical Tweezers Team: MaryamBadakhshi, Shannon O’Keefe, Laura Poloni, Hasmita Singh

  2. Overview • 1) Introduction • 2) Background & Applications • 3) Apparatus • 4) Laser Safety

  3. 1. Introduction

  4. Experiment Context --Presentation • No presentation component available in the Advanced Physics Labs courses • This presentation component is meant to be introduced to the students by the professor or TA of the course, in advance to the experiment

  5. Experiment Context --Students • Main purpose: • Give general information about the experiment and apparatus • Applications for the apparatus • Students may use this presentation to choose their experiment • Also to acquaint students with laboratory concepts, the equipment, and the safety procedure

  6. Relevant Courses • This experiment is based on knowledge of Energy Equipartition theory that may be related to back ground courses in both Engineering and Arts and Sciences : • Phy293 Engineering • PHY256H1  Arts and Science • This lab may also be used in the following courses: • PHY424/426/428/429 (A&S) and PHY327/427/428/429 (Engineering)

  7. Experiment Learning Objectives • Students will have the opportunity to : • Work on interesting and challenging experiments • Deepen their understanding of the underlying Physics • Further develop laboratory, analysis and communication skills • This presentation introduces the Optical Trapping apparatus and the many interesting applications of it

  8. 2. Background & Applications

  9. Manipulation of Nanowires • Four spheres trapped and rotated by linearly scanning with laser light (Tong et. al., Nano Letters, 2010) (Nam et. al., IJPEM, 2009) • Alignment and rotation of a silver nanowire

  10. Isolation and Visualization of DNA Staining with Fluorescent Dye Force-Extension analysis of the trapped DNA “Catching” a Single DNA Molecule Trapping of two beads (Gross et. al., Methods in Enzymology, 2010) (Gross et. al., Methods in Enzymology, 2010) Protein-coated DNA region Fluctuations in DNA molecule

  11. 3. Apparatus

  12. MainComponents Very Dangerous! Safe!

  13. 4. Laser Safety

  14. Optical Trap Laser Characteristics • 980 nm  Infrared range • 330mW maximum power • Collimated beam • Class 3B laser

  15. Laser Classification • Considered incapable of causing injury • Hazardous under direct and specular reflection, but not diffuse reflection • Direct exposure to beam is an eye hazard • Maximum power 500mW

  16. Hazards • Diffuse reflections • Invisible • Most dangerous procedure, contact your TA/Instructor • Eye injuries Stray Beams Beam Alignment Biological Effects

  17. Biological Effects • Cornea • Focussing element • Lens • Fine focus • Vitreous Humor • Retina • Image is projected from the cornea and lens • Connection to brain through optic nerve • Fovea • Sharp vision

  18. Biological Effects Retinal Hazard Region • Laser Light 400-1400nm • Focussed beam on retina • Amplification of light by human eye: 10,000 • Extremely large irradiance • Dependent on exposure time Thermal Effects • Overheating • Retina burns • Invisible light: damage may only be detected post-injury • Severe damage may require surgery or transplant • Scars / blind spots in the field of vision • Depending on location of the burn, could permanently lose: • Central vision • Peripheral vision

  19. Laser Hazards Control • Place “Laser Work in Progress” warning sign on door • Close and lock the room door • Remove wristwatches or reflective jewellery • Wear laser safety glasses AT ALL TIMES • - Wavelength and Optical Density • If someone unexpectedly enters, turn laser off • Turn off laser when changing samples • Return the laser controller key when completed • In case of an emergency, contact your TA/Instructor or UofT Campus Police 416-978-2222

  20. Questions?

More Related