FAQ  Donate 
Members List  
Calendar  
Search  
Today's Posts 
Welcome to Laser Pointer Forums! If you are looking for a laser you may want to check out the Laser Company Top Sites List. The link will open in a new window for your convenience. 

 LinkBack  Thread Tools  Display Modes 
07182010, 04:44 AM  #1  
 
Junior Member Join Date: Jul 2010
Posts: 28
Rep Power: 0 
lol what i a Mrad?
 
07182010, 04:53 AM  #2  
 
Class 1M Laser Join Date: Feb 2010
Posts: 121
Rep Power: 9 
milliradian. standard unit to measure divergence of a propagating beam
 
07182010, 04:57 AM  #3  
 
Junior Member Join Date: Jul 2010
Posts: 28
Rep Power: 0 
...lol what divergence
 
07182010, 04:58 AM  #4  
 
Class 1M Laser Join Date: Feb 2010
Posts: 121
Rep Power: 9 
Okay so all beams, contrary to uneducated opinion, don't go straight. Basically after they exit the lens, they will focus down to one spot, then "spread out." The less spreading that occurs, the smaller the dot will be at long distances. This spread is called divergence, and is measures in mrad. Anything else?  
07182010, 05:03 AM  #5  
 
Junior Member Join Date: Jul 2010
Posts: 28
Rep Power: 0 
so mrad is where the beam is the smallest after leaving the focusing lense?
 
07182010, 05:04 AM  #6  
 
Junior Member Join Date: Jul 2010
Posts: 28
Rep Power: 0 
so say a laser has .5mrad then the smallest point is .5 mrads away form he lense?
 
07182010, 05:08 AM  #7  
 
Class 1M Laser Join Date: Feb 2010
Posts: 121
Rep Power: 9 
Not quite. Mrad is a unit to measure the divergence (spread) of the beam. Where the beam is smallest is called the focal point  
07182010, 05:12 AM  #8  
 
Class 1M Laser Join Date: Feb 2010
Posts: 121
Rep Power: 9 
Radians is an angle. .5 Mrad means that that is the angle at which the beam gets larger the farther away from the focusing lens
 
07182010, 05:13 AM  #9  
 
Junior Member Join Date: Jul 2010
Posts: 28
Rep Power: 0 
oh so mrad is how storng the laser is at the focal point
 
07182010, 05:13 AM  #10  
 
Banned Join Date: Jan 2009 Location: In A State of Shock.
Posts: 11,871
Rep Power: 0 
Google and Wiki works really well also. Radian  Wikipedia, the free encyclopedia Beam divergence  Wikipedia, the free encyclopedia  
07182010, 05:14 AM  #11  
 
Class 1M Laser Join Date: Feb 2010
Posts: 121
Rep Power: 9 
Troll.
 
07182010, 05:16 AM  #12  
 
Class 3R Laser Join Date: Nov 2009 Location: Evergreen, CO
Posts: 2,027
Rep Power: 3388 
Milliradians, a division of radians, it's a standard angle measurement. Used in a lot of fields, not just lasers. Especially if you're talking about deviations less than a degree  specifically small divergences over long distances. (Satellites/microwave, astronomy, lasers of course, and in some cases firearms.) If you have a circle of radius x, one radian is the angle that occurs when the outer arc length is equal to the radius of that circle. One milliradian would be 1/1000th of that. If your laser source point (diode or OC mirror) is the 'center of the circle', and x measurement along your beam is the radius, the width of the beam at x feet would be your arc length. The angle developed between source point, along beam of specified (x) distance when the beam is at (n) thickness gives you your mRad reading. so radians=n divided by x; or radians = width of beam at distance x, divided by x. (same units.) With a laser that number will be far <1, so you'd measure it in milliradian or millirads. EDIT: Guess it was a troll, but, leaving it here for future searches.
__________________ 3392nm:REO LHIP HeNe 2mW ∙ 980nm:OLIKE 155mW 808nm:OLIKE 200mW ∙ JETL PLC 600mW(682pk) 780nm:OLIKE 120mW 685nm:18650 47mW 671nm:PGL3M 281mW DPSS ∙ PGL3C 278mW 655nm:LOC 254mW ∙ OLIKE 221mW ∙ Yob 320mW 638nm:Sanyo 40mW ∙ HL63133 200mW ∙ PGL3C 463mWpk ∙ ML520 700mW 633nm:JDS1145 HeNe 28mW ∙ JDS1145 HeNe 26mW 612nm:MG 05LOR151 HeNe 3mW ∙ REO LSTP 3mW 609nm:REO LHOR 1mW 604nm:REO LSTP 2mW 594nm:Rigel 3mW ∙ LG PGL3C 15mWpk ∙ Lasos 7512 3mW ∙ CNI MGL3 58mWpk 589nm:CNI PGL3C 106mW ∙ CNI PGL3C 85mW 561nm:CNI PGL3C 30mW(41pk) 556nm:CNI PGL3C 20mW(22pk) 544nm:JDS1675P HeNe 2mW ∙ REO LHGR 2mW ∙ Lasos 7786 2mW 532nm:PGL3C 150mW(180pk) ∙ PGL3C 578mWpk ∙ PLC 440mWpk 515nm:JDS 221420GL ArI 30mW 510nm:52mW DG#2 ∙ 50mW 26650 DG 488nm:Nlx DPSS 7mW ∙ JDS 2214 ArI 40mW ∙ JDS FCD488 DPSS 25mW ML:MG 65A106025 ArI ML 115mW 476/480nm:Nichia Diode 28mW 473nm:PGL3A 45mW(80pk) ∙ PGL3C 110mWpk ∙ PGL3C 95mWpk ∙ RPLB25 60mWpk 465nm:DTR NDB7676 2.03w 458nm:JDS 2214VL ArI 8mW ∙ JDS 2214VL ArI 12mW ∙ RHD Diode 1.7W 452nm:Osram SM 47mW 445nm:Yob 1410mW ∙ Polaris 156mW ∙ PGL3C 1200mW ∙ DTREHG 32650 2136mW 405nm:Yob 630mW ∙ Qfox 750mW ∙ JETL PLC 780mW Last edited by aryntha; 07182010 at 05:18 AM.  
07182010, 08:19 PM  #13  
 
Junior Member Join Date: Jul 2010
Posts: 28
Rep Power: 0 
thanks for your guys time. i understand now
 
07182010, 09:12 PM  #14  
 
Class 3R Laser Join Date: Jan 2009 Location: United Kingdom
Posts: 1,627
Rep Power: 65 
Really? Because most of those explanations were ridiculously complicated. Mrad is a way of measuring divergence, divergence is the rate at which the beam gets wider and wider the further away it goes. Mrad is basically measuring how quickly the beam gets wider. Little diagram to help
__________________  150mW Ehgemus MiniRPL Review  Collection of the Best Free games 445nm Custom build@1A  Old style Dorcy Jr. + purple anodized heatsink Dino Direct 50mW Flashlight unit DX True green 100mW Olike module @ 171mW in MiniRPL host Singleline Argon @ 52mW 488nm Peak PHR803T @ 110mA in Jayrob MXDL host DX Red 660nm 200mW Dragon lasers 190nm548nm Safety Goggles  
07182010, 09:15 PM  #15  
 
Class 3B Laser 
i feel like i'm on an episode of "punked", where Ashton? LoL michael
__________________ IN A CONSTANT STATE OF PICNIC I AM THE STATUS QUO ARE YOU A NEW MEMBER, OR EVEN MORE, ARE YOU NEW TO ONLINE FORUMS... READ THIS LASER POINTER FORUM ETIQUETTE for pot modding facts click below http://laserpointerforums.com/f51/potmoddingfaqs40510.html  
07192010, 03:04 PM  #16  
 
Class 1M Laser Join Date: Feb 2010
Posts: 121
Rep Power: 9   
Thread Tools  
Display Modes  
 