Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers



Laser Pointer Store

Laser Power Stability (rms)

DrSined

New member
Joined
Jan 1, 2016
Messages
18
Likes
3
Points
0
Hi, simple question, What exactly mean value "Laser Power Stability (rms)" at DPSS laser module?

Please explain as detailed as possible.

Thank you.
 

Hap

Super Moderator
Staff member
Joined
Sep 5, 2013
Messages
8,460
Likes
1,622
Points
113
Hi, simple question, What exactly mean value "Laser Power Stability (rms)" at DPSS laser module?

Please explain as detailed as possible.

Thank you.
Laser stability means how stable a laser is. For example, a laser with a stability of 10% will not drift more then 10mW's, while a laser with a stability of 1% will not drift more then 1mW :yh:

-Alex
 

diachi

Well-known member
Joined
Feb 22, 2008
Messages
9,563
Likes
1,384
Points
113
Laser stability means how stable a laser is. For example, a laser with a stability of 10% will not drift more then 10mW's, while a laser with a stability of 1% will not drift more then 1mW :yh:

-Alex
A 100mW laser* with those stability numbers will drift no more than you say.

A 1W Laser with a stability of 10% will drift no more than 100mW. ;) It's a percentage of total output.
 
Last edited:
Joined
Oct 16, 2015
Messages
499
Likes
145
Points
0
Lots of info out there. From good simple explanations to complex white papers. Also, note that it's specified in percentage, %, of the laser power output as pointed out. Here's one source.
 

Hap

Super Moderator
Staff member
Joined
Sep 5, 2013
Messages
8,460
Likes
1,622
Points
113
A 100mW laser* with those stability numbers will drift no more than you say.

A 1W Laser with a stability of 10% will drift no more than 100mW. ;) It's a percentage of total output.
Dangit! :mad:

-Alex
 

ultimatekaiser

Well-known member
Joined
Mar 10, 2013
Messages
2,823
Likes
470
Points
83
yes. basically if a laser says ">100mW 5% stability over 4 hours RMS" it means that its guarenteed to output at least 100mW average or better minimum with no more than a deviation of 5% total output power over 4 hours at a consistent ambient room temperature while running with adequate heat-sinking/cooling.
 
Last edited:

Cyparagon

Well-known member
Joined
Sep 12, 2007
Messages
9,580
Likes
1,070
Points
113
Mr. kaiser is confusing rms with peak. "5% rms" is COMPLETELY different from "5% peak." A 100mW 5% (rms) stability laser will vary considerably both over 105mW and under 95mW. I'm not going to try to explain rms in one forum post, but the easiest plain-English approximation is "average noise." The google can tell you all about rms if you want to know more.
 
Last edited:

ultimatekaiser

Well-known member
Joined
Mar 10, 2013
Messages
2,823
Likes
470
Points
83
Yes and no. You're absolutely right about the nose bit. But on power specifications, if it's listed >100mW, Then that is its minimum output. It should always do more than listed. If it does less at any time, then it is considered defective/mis-calibrated. I do digress and note most of my lab lasers note power and noise separately on their spec sheets. (And I own quite a few) so it's important to check both. I've often seen companies list both power and noise under the same % difference, but not always. For example my GCS-405 notes <2% +\- <0.2%rms total for noise and <4% change in power over 8 hours. Read the specs carefully.
 




Top