User talk:Joshuakh

Beam divergence
Hi Joshuakh. I reverted your edit to Beam divergence. Before making statements about what is mathematically correct, make sure you understand the mathematics and the physics involved. In this case, see Fourier optics, which gives an introduction to the relevant mathematics behind that deceptively simple formula.--Srleffler (talk) 02:10, 31 March 2015 (UTC)


 * Hi Srleffler. Thanks for your reply. I haven't use Wiki as a communication tool. So I am not sure this is right tool to talk to you.
 * The reason I as an optical professional could not understand your sentence was you have assumed it in the laser cavity context where there is no mention about it.
 * e.g. when you say 'before', there is no way to understand the before of collimated or before of cavity etc...
 * Anyway I am not sure whether this comments make sense to you or not. If not please correct me.
 * Thanks- Joshua or Kihong
 * This works fine for communication: your talk page is the place for other editors to correspond with you. Since I left you a message here, I set your page on my watchlist so that I would see your reply. This is normal "etiquette" for Wikipedia. User talk pages are for one-on-one communication. Broader discussion of an article is best done on the article's talk page.
 * The statement you had edited doesn't presume a laser cavity or any other specific optical system. The divergence of light collimated by a lens is fundamentally related to the diameter of the beam at the front focal plane of the lens. This is not at all obvious. It arises from the mathematics of Fourier optics. "Before" just refers to the light before it enters the lens. More formally, it refers to the optical space in front of the lens. I see now, though, that the reference to the narrowest point of the beam is not correct. It is the diameter of the beam at the front focal plane of the lens that determines its divergence after the lens. I'll fix that shortly.
 * By the way: When you leave messages on talk pages, always end your message with " ~ ". Wikipedia automatically converts this into a "signature" with your username and the date and time. This makes it easier to tell who wrote what, and when.--Srleffler (talk) 01:25, 1 April 2015 (UTC)

Hi Srleffler. I think we are in the same page now. Thanks for your clarification. Joshuakh Joshua Kihong 01:23, 3 April 2015 (UTC)