Hmm. LG Rigel just... stopped working.

My Rigel-2 was working just fine earlier today; its only a few months old and hasn't really shown any trouble at all...

It was working when I put it back in the case earlier today and, tonight - just - nothing. Well, nothing but a trickle of IR. (thanks to a nightshot camera). Tried new batteries, nothing.

Hopefully LG will make this painless, but... wow.. do Rigels fail this easily, historically? I can't imagine what happened while it was sitting in the case in the last few hours.

All DPSS lasers can be affected by temp, atmospheric pressure and lots of other unseen factors, more so the blue and much more so the yellow, so sorry, but it is part of the behavior of these things. Best wishes for a happy ending! -Glenn

Glenn - in the long term, any suggestions on storage for these lasers? Preventative measures?

Has anyone else had a 593.5nm laser just give up? Haven't even used it that extensively... Good thing is, it's well within warranty (lets hope that goes smoothly - shipping to canada is always a pain) but I'm hoping this was a freak occurrance.

What's nuts is, my GP4 4mw 532 from 2002 (!) still works! That thing's 8 years old now!

I recently received my blue & yellow from Glenn's group buy. The blue has no problems, however the yellow appears to be very prone to low ambient temperatures.

When I opened up the package and put the batteries in there was no output at all. Luckily enough I was aware of this "quirk" and waited a few minutes to let the body warm up. It then lit up nicely.

Don't even think of using it outdoors where you are


Jerry

Waiting on a 589 from Glenn's GB: The one you got, is it a 593.5?

And, you know what - that's a good point. The closet I keep these in isn't well insulated and, well, it is cold tonight. (Okay, let's be honest - i'm at 8000ft. It's freaking frigid.) Giving that a shot; leaving it on top of my computer case for a bit. Hope it could be as simple as that.

i would say just put it in your pocket, but it is too fragile.

microwave it. /sarcasm.

i hope it works, that would really suck to have to go through warranty work and wait for a new one.

Yeah, never know if something as simple as letting it warm up was all it took to get it working again unless you try it. Best of luck

Okay so - here are some lessons learned. A triple factor here lead me to believe the laser was dead.

1) Lithium batteries, while GREAT in this laser, die immediately when they do choose to die. They do not taper off. This is one of the good thing about lithiums: they deliver pretty much full 1.2 volts until they suddenly do not. This is what made the laser appear to have 'died in its sleep'. I got no warning on the batteries.

2) Combined with the affect of temperature on this laser (this was the other culprit) - switching out 'known good alkalines' (i.e.: they work great in a 532 laser) may not even get a 593.5 to lase, especially when "Cold as the Rocky Mountains".

3) Rechargeable NiMH batteries do not have a good shelf life - especially small 800mAH AAAs. This was the third set I tried. "How could they ALL be dead?" .. Well guess what.

Between "suddenly dead" lithiums that were good a few hours ago (that's just how lithiums die), and "not quite good enough to get it going in cold temp" alkalines, that worked fine in my 532, and rechargeable AAAs that suffered from idle drain, and a touch of "my $300 laser has bitten it" panic, I concluded: dead laser.

An hour and a beer later: Warmed up the laser as suggested and popped the NiMHs back on the charger. green.. green.. dim orange... Back in business.

Maybe a waste, somewhat, of a panic thread but: perhaps it could provide someone else some pause when looking for help with one of these 'fickle' DPSS lasers: Warm it up. Don't discount the obvious. And coincidences do happen.

Oh. And take a beer break.

This is GREAT information to have posted from time to time. People expect all of their "pointers" to act the same. Your story here clearly illustrates that they do not.

Also, it is a reminder to NooB's (and even some of us veterans) to post a question here BEFORE tearing the laser apart. I have lost count of the number of lasers I have rebuilt for someone who "opened it just to see what was wrong" and broke a perfectly good laser.

Pleased with the happy ending. Thanks for sharing

Peace,
dave

Yeah, those 593.5nms sure are a pain! Its amazing to me that they could even make a pointer like that, the DPSS process for 593.5nm is much more tricky than any of the relatively straightforward ways to get 532nm or 473nm from 808nm, and we know how poor a 473nm can be in bad weather.

When I had a few of these 2mW ones, I was always in a conundrum about how to rate them because it'd be so common to see them swing from 0.5mW to 4mW several times in just 30 seconds. You get them a little too cold and they wont start. Use it for a little bit and its too warm. Crazy stuff!

Loosely put, to get that 593.5nm they have to use both the 1342nm and 1064nm lines from the Nd crystal and get the correct operation/levels out of both of them to get good 593.5nm. Most other DPSS we're used to only uses a single line of the Nd crystal.

Great price for something so special though. Just not the 'point-and-click' interface we get spolied by with collimated diode lasers (It'd be nice for CNI to have a disclaimer!)

People who haven't been into lasers that long, or who haven't learned about the intricacies of DPSS for whatever reason, commonly believe that their lasers should work the same regardless of temperature, power output, battery condition, etc. (this is no fault of their own, however.. this information isn't provided with the lasers themselves, but must be found through research) The truth of the matter is that DPSS laser pointers (and most DPSS lab-style modules) really are like snowflakes. No two are exactly the same. Take two lasers from the same line, with sequential serial numbers. Each one will react differently to ambient temperatures, unstable power sources, and even normal operation. There will be output peaks and valleys at different times, mode-hopping may occur at temperature and voltage extremes.. About the only similarities will be AVERAGE power output, general temperature behaviors and hopefully beam quality.

Many users get a new laser, fire it up and then freak out when the power drops out or the mode changes once the laser has warmed up, or they freak out when nothing happens in a cold environment. In neither case is there actually a defect involved, rather merely abnormal operating variables leading to unexpected output issues.. perfectly normal for all simple DPSS lasers. It's good to see this kind of information pop up once in awhile to remind everyone.

My first Rigel failed. In spectacular fashion as a matter of fact. However, it was entirely my fault and had nothing to do with anything LG or CNI did (or didn't) do. My laser was a little champ that was consistent with it's output and fired the first time, every time.

I really miss it.

Just wondering -- Does anyone in this thread (Electrofreak, perhaps?) know how/if the 589 DPSS process differs from the (rather convoluted) 593.5 DPSS process?

Been trying to find info on this, seems to be hard to track down.

I had the same the issue with my green module a while ago, panicked because no batteries were working with it and I was getting no output

But I left it switched on for 20 seconds out of it's case, and held the head in my hand and yay back on again

It's quite weird how temperature can effect DPSS lasers so much!

aryntha said:

Just wondering -- Does anyone in this thread (Electrofreak, perhaps?) know how/if the 589 DPSS process differs from the (rather convoluted) 593.5 DPSS process?

Been trying to find info on this, seems to be hard to track down.

Click to expand...

All I can do is speculate. 589nm is the same wavelength as the "sodium line" guide stars observatories use to excite rare gasses in the upper atmosphere. These lasers use bismuth doped fiber or raman shifting in fiber to generate 1178nm light which is then frequency doubled using standard non-linear crystals (LBO, KTP) to produce 589nm light. This process is a bit more complex than we'll be seeing in a pointer or portable, and really more complex than pretty much any Chinese company is going to tackle.

There have been some new lines (I use the word new very loosely since I really don't know just how new they are... new to most of us would be more accurate) being discovered in Nd:YVO4 that *might* include a line at 1178nm, which would make the whole thing very practical (457nm blue lasers are becoming very popular and powerful and are a result of doubling the 914nm line in Nd:YVO4.. as opposed to doubling the 946nm line in Nd:YAG to get 473nm. 457nm lasers can potentially produce tens of watts of power, impossible with 473nm.). Nd:YVO4 is a better candidate than Nd:YAG for use in simple DPSS lasers because it has a wider pump absorption range (meaning the 808nm pump diode need not be so precisely temp. controlled) which makes it much more stable. Also, some of it's lines are quite powerful, resulting in some very cool new color possibilities for high-powered lasers. As previously mentioned, it also provides other lines of output than just 1064nm which makes a few new colors possible through doubling. No data that I could find shows a 1178nm line, but this stuff is all pretty new still. Data in the public domain isn't likely to have such info, but the fact that the Chinese are pushing 589nm tells me that there must be a relatively simple way to do it.

It could also be sum-frequency generation just like 593.5 (a VERY good possibility, perhaps the most likely) only using Nd:YVO4 instead of Nd:YAG, thereby providing slightly different wavelengths resulting in a slightly different shade of yellow.

I'm nearly 100% sure the key lies in the use of Nd:YVO4 or Gd:YVO4 instead of Nd:YAG. Most green DPSS have been using Nd:YVO4 for some time now, and that's a big reason why they're inherently much more stable than most other DPSS lasers, so applying the same tactics to the design of other colors will lead to better stability from simpler cavities.. in other words, it's just perfect for Chinese lasers.

wait, so the green lasers we have are not nd:yag?