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The niche LASER market is
replete with copycats and knock-offs. At the left is a photo of a
disassembled 200mw 532nm Hand-Held LASER from a distributor in China – a
distributor who also sells a plethora of other things from jelly beans
to iPod speakers and "Bose-like" entertainment systems. A few years ago
(2005) – before eBay banned LASERS
over 5mw – I purchased this fixed focus unit from a seller on eBay.
Upon initial examination, the
LASER worked perfectly – it was able to light matches and cigarettes,
and do all the things claimed for a LASER of this class. It was "hot"
because there was no Infrared filter on it.
Being curious, I unscrewed the
barrel's components which were made of brass – in fact, all of the
heat-bearing surfaces were brass – a quality feature found in most good
equipment. After exposing the lens assembly, I was shocked to discover
that the LASER diode and the lens assembly were "glued" to the
electronics module with a band of silicone bathtub caulk.
Now while this may seem to be a
simple way of shock-mounting the diode, it also has the added
disadvantage of isolating the main heat-generating component – the LASER
diode – from all of that great metal that the Hand-Held LASER case was
made from. This is a classic example of a
"home-brew, DIY" LASER built into a generic case. In use, the diode
would get extremely hot, and in two weeks of normal, average use, the
silicone had hardened, become brittle, and started to flake off. A few
months after that, the LASER diode and collimator lens were hanging by
the wires, as silicone bathtub caulk can't tolerate the heat. The LASER,
although it still worked, had become useless because the thin wires
inside the potted diode assembly had broken off flush with the epoxy,
and there was no way to solder them back together. This LASER is now the
occupant of Great Kills Landfill in Staten Island, NY. $200 bucks down
the tubes (the seller in China went belly-up when
eBay banned everything but toy LASERS).
Moral of the story:
You can't always judge quality by the price you pay, but if you want
quality merchandise, you'll pay for it. If you pay $100 for a 200mw
LASER, chances are you'll get something like this – or
maybe even worse.
Deal with reputable people – preferably people in your own country – and
you should be OK.
We are here for the long-haul.
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