Re: Green laser pointers (fwd)

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

Original poster: Steven Roys <sroys@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Wed, 27 Jun 2007 11:00:02 -0700
From: Peter Lawrence <Peter.Lawrence@xxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Green laser pointers

Steve, or anyone else...,

I've always wondered why they can make such hi-powered green
lasers, but not red or yellow ?

-Pete Lawrence.


[They do make high-powered solid-state red lasers, but yellow I'm not so
sure about.  The green ones are more complicated than the red, which are
just laser diodes with red output.  A green dpss laser has a solid-sate IR
laser (808 nm typically) that's used to pump another laser crystal (Nd:YAG
or Nd:YVO4) that puts out 1064 nm "light".  The 1064 nm radiation is then
passed through a frequency doubling crystal (KTP) to get the nice green
532 nm.  I'm not sure how easy it is to find a medium that lases at a
specific frequency, and I would imagine there are peaks in the doubling
process as well, making off-resonant wavelength conversion less efficient.
SRR]



High Voltage list wrote On 06/26/07 04:20 PM,:
> Original poster: Steven Roys <sroys@xxxxxxxxxx>
> 
> These aren't high voltage, but...
> 
> If you've been living in a cave for the past few years and haven't seen
> them, green laser pointers look MUCH brighter than equivalently powered
> red laser pointers. The beam is also clearly visible at night, hence their
> use by amateur astromers to point out stars. But even if you're not an
> astronomer, they're just very cool to shine around, and will project a
> visible green spot thousands of feet away in the dark.
> 
> These are (nominally) 5mW green laser pointers that use 2 AAA batteries,
> and I'd sell them for $35 shipped in the continental US. If you're
> interested, contact me off-list at srrinmd@xxxxxxxxxxx and let me know so
> I can get an idea of how many (if any) to order.
> 
> Steve
> 
>