1.Lasers: What they are & how they work; Laser tweezers: moving things with light without touching; Laser applications: science, technology, & everyday life; 2.Invisibility: Is this possible? Yes!!! How it works & when we can buy our invisibility clothes? 3.Energy from light: Solar cells & solar cell paints; 4.Holography & Diffraction Gratings Movie on Optical Science & Technology

Flashlight Light bulb Laser Light bulb Flashlight Laser Rays: Waves:

Principal components & how lasers work 1. Gain medium 2. Laser pumping energy 3. Mirror (100% reflection) 4. Output coupler mirror (98-99% reflection); 5. Laser beam

The term “LASER" is an acronym for Light Amplification by Stimulated Emission of Radiation. Laser light is spatially coherent: either emitted in a narrow, low-divergence beam, or can be converted into one with the help of lenses. Lasers are emitting light with a narrow monochromatic wavelength spectrum. Laser in a research lab:

Intensity-distribution curve of light from a White fluorescent tube Intensity-distribution curve of light from a i ncandescent lamp Compare different light sources: Laser

Some of numerous applications In CD, Blue-Ray, DVD, andHD-DVD players, Bar code readers; Laser pointers & laser tweezers; welding metal and other materials; "marking"—producing visible patterns such as letters; Military applications: range-finding, target designation, and illumination, weapons; Medicine: laser surgery (i,.e., correction of cornea in the eye), diagnostics, and therapeutic applications; Holography; Laser microscopy;

Moving Matter with Light without touching ??? To explain why tails of comets always point away from the Sun, Kepler suggested that the Sun was exerting a sort of radiant pressure. This led him in 1609 to propose sailing from the Earth to the Moon on light itself. This was and still is the stuff of science fiction. Johannes Kepler

Moving and shaping matter with light 400 years later Kepler's ideas about moving matter with light are a reality (manipulated with invisible infrared light)

9 Moving and shaping matter with light 400 years later Kepler's ideas about moving matter with light are a reality (manipulated with invisible infrared light)

10 A highly simplified view on How “Optical Trapping” Works Along beam axis: Laser beam  Refraction changes light (photons) propagation direction;  In return, the particle experiences an opposite force;  Need refractive index of object > than that of medium;  Optical forces for micron-sized objects: In the lateral plane:

11 Equivalent ways of steering Objective Focal Plane Prism Objective Multiple traps: beam steering and shaping using spatial light modulators Objective lens Focal plane Phase-only SLM Image can be scanned at (2) Acousto-Optic Deflectors (1)Galvano mirrors can be scanned at

12 Dynamically-reconfigurable focused laser beams Infrared CW Nd: YAG λ=1064nm co-localized with a HeNe Laser, λ=632.8nm Intensity Beam steering Objective

13 Manipulation of multiple micron-sized objects Manipulation by CW Nd: YAG (λ=1064nm), visualized by HeNe laser (λ=632.8nm)

14 Manipulating micron-sized bacteria 9x9 array Laser power ~ 10mW per trap 6x6 array Bacteria Pseudomonas aeruginosa:  Burns, cancer patients, cystic fibrosis patients  Planktonic cells send quorum sensing molecules/signals to determine if there are enough bacteria to start a biofilm  Resistant to antibiotics

15 Particle manipulation with multiple traps

Shaping matter by infrared laser beams

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Thank you !!!  Optically-manipulated micro-string ( using an infrared laser beam);