On Fri, 9 Jan 2009 06:29:51 +0000 (UTC), (Dave
Martindale) wrote:

(Samuel M. Goldwasser) writes:
(Mike S.) writes:

The KTP frequency-doubling crystal may be more temperature-sensitive than
is normal. This is a known characteristic, but perhaps the crystal is
damaged or improperly aligned.

It may be normal. Green pointers have no temperature control and the
entire process is tempterature critical. So as various parts warm up,
the efficiency changes and this can be significant. Some are worse
than others but they all vary. At least yours is brightest when
it's warm.

More info: I put the pointer into the refrigerator to cool for a few
hours. At that temperature, the green output is barely visible
projected onto a surface a half inch from the end of the pointer. I
measured the current drawn from the batteries (remove end cap, insert
ammeter into the circuit), and it was about 270 mA - almost the same as
when it is operating at its brightest. Current appeared to be steady
too.

I also had the beam hitting a surface at a shallow angle, and I could
see that as the output changed in intensity, the intensity profile
across the beam changed a great deal. Looks like one of the lasers (I
don't know whether the 800 nm or the 1060 nm one) was changing its mode
mixture quickly.

Once fully warmed up, it was back to normal.

From this, I'd conclude that the electrical side of the pointer is fine:
no intermittent connections, and the laser diode current regulator is
working. But at least one of the optical components is extremely
temperature sensitive. It seems that if this particular pointer is
going to be useful for pointing out things in the sky on cold clear
nights, it will have to be kept in an inside pocket between uses.

Thanks to everyone who commented.

Dave
Orion is very good about standing behind their products. I would
check with them even if you aren't the original purchaser. They might
agree to exchange it for free.