Talk:Speckle pattern

message: The recent alteration by an anonymous contributor is incorrect;
"If light of low coherence (i.e. made up of many wavelengths) is used, a speckle pattern will not normally be observed, since the speckle pattern varies over time and for light with a large bandwidth the speckle pattern will shift fast enough for the eye or detector to average out to give a uniform field of view"
The lack of speckle in non-coherent light has got nothing to do with speckle patterns shifting in time, but is due to the fact that each wavelength produces its own stationary speckle pattern; the dimensions of the speckle patterns vary with wavelength, and the individual speckle patterns will therefore normally cancel one another out.  Speckles may still be observed if the bandwidth is narrow enough, or the the surface is only slightly rough (speckle in your fingernail in sunlight).Epzcaw (talk) 07:54, 5 June 2008 (UTC)
thread_title:  Correction 

message: I have a science PhD, and have done a fair bit of work with laser optics. I know very well what causes speckle, but it was hard work for me to get through the basic "how speckle occurs" in this article. As it stands, like many Wikipedia articles, much of this article is near useless to anyone who doesn't already know the subject (as well as a lot of relevant background at a high level). Anyone care to have a try at making it accessible to a general audience? • TheBendster (talk) 11 March 2009, 20:37 (UTC)
I've added an analogy with water waves in an attempt to do this.  Comments welcome. Epzcaw (talk) 09:04, 28 March 2011 (UTC)
thread_title:  Needs a clear and simple lead 

message: To my understanding speckle is not a random phenomenon but a deterministic one. While the cause of the specific speckle pattern may be random (like the distribution of the scattering material or in case of light random changes of the light source) the speckle pattern itself is a deterministic interference of waves. In case of acoustics or acoustic imaging you will find the same speckle pattern without random changes in case you send the same signals from the exactly same direction. Therefore I would like to propose to rmove the "random" in the first sentence in the definition of the Wiki page.
Looking forward to your comments.  — Preceding unsigned comment added by 187.13.53.119 (talk) 17:41, 25 April 2012 (UTC)
thread_title:  random? 

message: The subjective speckles associated with viewing a surface illuminated by a laser should not be confused with the image of the Fundus (eye) seen when viewing a small monochromatic lamp (laser or not) in the darkness. The latter pattern is caused by the fixed arrangement of blood vessels around the Optic disc, and shows clearly the branching of the vessels. If anyone is interested, please find a source and add to the article. David Spector (talk) 14:37, 3 November 2014 (UTC)
thread_title:  Disambiguation with another similar pattern 

message: The two paragraphs listed here are not of any actual application. There is no reason to review recent papers in this article other than self promotion. Wikipedia should be a general overview, NOT a lit review (potentially for self promotional purposes as well).  — Preceding unsigned comment added by 129.105.14.165 (talk) 23:19, 21 January 2016 (UTC)
thread_title:  Dental "applications" 

message: How can the zeroes of E have much significance? Why should angular momentum be concentrated here? Electromagnetic radiation obeys a linear equation, but the notion of a "vortex" requires a nonlinear equation to sustain itself. So this section seems scientifically weak. 178.39.122.125 (talk) 11:36, 8 October 2016 (UTC)
thread_title:  "Optical vortices in speckle patterns" 

message: There's a 2020 proposal to merge this article and Speckle (interference). My view is that the latter is the better target, as it broader in scope and is the older article (started in 2009 compared with 2019). Klbrain (talk) 16:58, 13 April 2021 (UTC)
replies: text: Klbrain (talk) 15:18, 12 December 2021 (UTC)
thread_title:  Merge proposal