|
|
Line 1: |
Line 1: |
| [[File:Light intensity distribution.jpg|thumb|7x7 matrix using green laser and diff. beam splitter (Courtesy of Holo-Or)]]
| | 1 He is well know by the name of Courtney Poff but he doesn't like when people use his full named. To go to karaoke is worthwhile hobby her husband doesn't approve of the. After being associated with his project for years he became a credit authoriser. Pennsylvania is where her residence is but she needs to transfer because of her spouse and children members. Check out his website here: http://www.freewebsite-service.com/aerian<br><br>Feel free to visit my blog post; bilete de avion pegasus; [http://www.freewebsite-service.com/aerian http://www.freewebsite-service.com/], |
| The '''diffractive beam splitter'''
| |
| <ref name="www.amazon.com">[http://www.amazon.com/Diffraction-Gratings-Applications-Optical-Engineering/dp/0824799232#reader_0824799232 Diffraction Gratings and Applications, Loewen, Erwin C. and Popov, Evgeny. Marcel Dekker, Inc. 1997.]</ref>
| |
| <ref name="www.amazon.com1">[http://www.amazon.com/Digital-Diffractive-Optics-Introduction-Technology/dp/0471984477#reader_0471984477 Digital diffractive optics: an introduction to planar diffractive optics and related technology, Bernard C. Kress, Patrick Meyrueis , 2005.]</ref>
| |
| (also known as '''multispot beam generator''' or '''array beam generator''') is a single [[Lens (optics)|optical element]] that divides an input [[Laser beam|beam]] into N output [[laser beam|beams]].<ref name="books.google.com">[http://books.google.com/books?id=NFrG-zFrIDYC&lpg=PP3&dq=diffractive%20optics&pg=PA83#v=twopage&q&f=false Diffractive Optics – Design, Fabrication and Test, O'Shea, Suleski, Kathman and Prather, 2004. p.83]</ref> Each output [[laser beam|beam]] retains the same optical characteristics as the input beam, such as size, [[polarization (waves)|polarization]] and [[phase (waves)|phase]]. A diffractive [[beam splitter]] can generate either a 1-dimensional beam array (1xN) or a 2-dimensional beam [[wikt:matrix|matrix]] (MxN), depending on the [[Diffraction#Patterns|diffractive pattern]] on the [[Lens (optics)|element]]. The diffractive beam splitter is used with [[Monochromatic electromagnetic plane wave|monochromatic light]] such as a [[laser beam]], and is designed for a specific [[wavelength]] and [[Angular distance|angle of separation]] between output beams.
| |
| | |
| ==Applications==
| |
| | |
| Normally, a diffractive beam splitter is used in [[tandem]] with a [[Lens (optics)#Types of simple lenses|focusing lens]] so that the output beam array becomes an array of [[Focus (optics)|focused]] spots on a plane at a given distance from the lens, called the "working distance." The [[focal length]] of the lens, together with the [[Angular distance|separation angle]] between the beams, determines the separation distance between the [[Focus (optics)|focused]] spots. This simple optical set-up is used in a variety of high-power [[laser]] research and industrial applications that typically include:
| |
| | |
| :* [[Laser cutting|Laser scribing]] ([[solar cell]]s)
| |
| :* [[Laser cutting|Glass dicing]] ([[Liquid crystal display|LCD displays]])
| |
| :* [[Perforation]] ([[cigarette filter]]s)
| |
| :* Beam sampling <ref name="LC">[http://www.lasercomponents.com/fileadmin/user_upload/home/Datasheets/holoor/beam_sampler.pdf Beam sampler]</ref>(Power monitoring & control)
| |
| :* 3-D [[Motion detection|motion sensing]] <ref name="primesense">[http://www.google.com/patents/about?id=6WFWAQAAEBAJ OPTICAL DESIGNS FOR ZERO ORDER REDUCTION(patent)]</ref> ([[Kinect|Example]])
| |
| :* Medical/aesthetic applications (skin treatment) <ref name="medical1">[http://www.photonics.com/Article.aspx?AID=42337 Fractional Laser Skin Treatment Using Diffractive Optics]</ref>
| |
| | |
| [[File:Phase image.jpg|thumb|Periodic etch patterns on a)19x19 diff. beam splitter and b)1x31 splitter (courtesy of Holo-Or)]]
| |
| | |
| ==Design principle==
| |
| The theory of operation is based on the [[wave]] nature of [[light]] and [[Huygens–Fresnel principle|Huygens' Principle]] (See also [[Diffraction]]). Designing the [[Diffraction#Patterns|diffractive pattern]] for a beam splitter follows the same principle as a [[diffraction grating]], with a repetitive pattern etched on the surface of a substrate. The depth of the [[etching]] pattern is roughly on the order of the wavelength of light in the application, with an adjustment factor related to the substrate's index of refraction. The [[etching]] pattern is composed of "periods" –identical sub-pattern units that repeat cyclically. The width d of the [[period (physics)|period]] is related to the separation angle θ between output beams according to the [[Diffraction_grating#Theory of operation|grating equation]]:
| |
| | |
| :<math> d \sin \theta_m = m \lambda </math>
| |
| | |
| '''''m''''' represents the order of the [[Diffraction|diffracted beam]], with the [[Diffraction grating|zero order]] output simply being the undiffracted continuation of the input beam.
| |
| | |
| While the [[Diffraction_grating#Theory of operation|grating equation]] determines the direction of the output beams, it does not determine the distribution of [[intensity (physics)|light intensity]] among those beams. The [[Power (physics)|power]] distribution is defined by the etching profile within the unit period, which can involve many (not less than two) etching transitions of varying duty cycles.
| |
| | |
| In a 1-dimensional diffractive beam splitter, the diffractive pattern is linear, while a 2-dimensional element will have a complex pattern.
| |
| | |
| For information on manufacturing process, see [[lithography]].
| |
| | |
| ==References==
| |
| {{reflist}}
| |
| | |
| == External links ==
| |
| * [http://holoor.co.il/Diffractive_Optics_Publications/BeamSplitter-Article.pdf HOLOOR Diffractive beam-splitter]
| |
| * [http://axetris.com/diffraction_gratings.htm Axetris Diffractive Optics]
| |
| * [http://www.youtube.com/watch?v=LSJXXIpc6aA Video presenting diffractive beam splitter developing. IFTA]
| |
| * [http://www.youtube.com/watch?v=QHrzIcZ7Pw8 Video.Light propagation simulation through diffractive splitter]
| |
| | |
| [[Category:Optical devices]]
| |
| [[Category:Diffraction]]
| |
| [[Category:Lenses]]
| |
1 He is well know by the name of Courtney Poff but he doesn't like when people use his full named. To go to karaoke is worthwhile hobby her husband doesn't approve of the. After being associated with his project for years he became a credit authoriser. Pennsylvania is where her residence is but she needs to transfer because of her spouse and children members. Check out his website here: http://www.freewebsite-service.com/aerian
Feel free to visit my blog post; bilete de avion pegasus; http://www.freewebsite-service.com/,