RE: laser update (fwd)

["High Voltage list" <hvlist@xxxxxxxxxx>]

Original poster: Steven Roys <sroys@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Thu, 05 Jul 2007 06:31:49 -0400
From: "Mccauley, Daniel H" <daniel.h.mccauley@xxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: RE: laser update


Steve,

One thing to be careful of is that non-IR filtered DPSS lasers are not
as powerful as their power specifications may indicate.  This is
frequent among
most DPSS lasers sold on EBAY.

The problem is that there are large components of both "green" and IR
light produced by a DPSS laser in the output beam.  If the IR light is
not filtered, than the power measurement made by the manfacturer, or
seller, also includes this IR light, so you are not getting 30mW worth
of "green" light.  

Vendors such as Wicked Lasers, do use IR filters on the "green" lasers
and their power numbers are indeed representative of the "green" light
produced by the laser.

Dan

[Yep, they measure the IR as well as the visible light, but for the
price/mW, we couldn't resist those lasers, even if some of the power is
IR. The information that we found on the lasers seemed to indicate that
most of the output was green though.  A laser power meter is on my list of
things to acquire or build though - even if it's not calibrated, I'd be
able to check the IR filtered to unfiltered ratio to get a rough idea of
how much IR is getting through.  A simple lpm is really pretty simple -
all I'd need would be a pin photodiode.  Radio Shack doesn't carry them
though, so it's off to the internet. SRR]