I obtained a LaserCentury 150mW TEC cooled 532nm green laser module...
Boys'n girls... if you want a solid green with no compromises on
optical quality, this is the laser you've been waiting for...
First, let me state... I've been spoiled by the beam quality of large gas ion lasers.Code:Manufacturer Specifications: Model Number: GL532T-XXX Output Power: 150mW Output Wavelength: 532nm Beam Mode: TEM00, CW Power Stability(RMS): 5% (over 2 hours) Beam Divergence: <1.5mrad Beam Diameter: <1.0mm Warm Up time: <5 minutes Directional stability: <0.05mrd (after warm up) Ellipticity: >90% Output noise(RMS): 20% around 50~200KHz Beam width: 0.1nm Operating Temperature: 5 ~ 35 degrees Modulation: >10KHz, TTL Mode (as tested, analog and no mod. avail.) Manufacturer MTBF: >10000 hours Dimensions (Laser): 1.5" x 1.5" x 4" (at base) Dimensions (Driver): 3" x 1.5" x 7" Operating voltage: 120VAC (as tested, other options available)
I've been less than impressed by most diode lasers I've seen, even the scientific units
from Coherent and Spectra...
Well this little module successfully forced me to re-evaluate my opinions on
diode based laser technology, and did it at a surprisingly low cost!
Power Levels
This laser didn't dissappoint in the power category...
177mW of true 532nm green!
Now, one of the things the modern laserist needs to be aware of is that once a laser
enters the Class IIIb range, manufacturers don't usually bother filtering out the
"waste" IR beams. This is because the CDRH doesn't "care" as long as the
class designation is accurate in defining the total power output (i.e. >5 - <500mW for Class IIIb).
The second thing is that often, more than half the total power output of a filterless
DPSS module is in the invisible IR range!
The last is that is that vendors will include any invisible IR "waste" beam present in
their rated power levels... This isn't inherently "wrong" because that total number is
very important for eye safety considerations. What I do find less than ethical is that
many new manufacturers are specifically leaving the IR filter off soley so they
can claim higher power levels for marketting. That 200mW DPSS laser you bought off ebay
may in fact only generate 80mW of usable green with the rest in IR!
So, I was very pleasantly surprised to find an IR filter on this unit! Checking with
an external IR bounce mirror confirmed that the onboard filter was working as designed.
Beam Quality
The laser didn't dissappoint in this category either... The beam diameter is the smallest
I've seen in a laser of this price level... the divergence is so low that the beam was
still point sized over 30 feet!
Mechanical details
Internals: This head is TEC cooled and maintains extraordinary stability for
this class.
Laser Head: This is where the cost savings start to show... While the head
is build solidly, the annodization (the coloration) is amateurish and may show
premature wear over usage... The first hint was that close examination
shows the black anno to be more of a hue of green... Running a swipe
of denatured alchohol over the base confirmed that the anno die wasn't
properly sealed... Aside from the cosmetic detail, the laser head had a
satisfying heft and was well built to very tight tolerances...
The dimensions of the head are 1.5" x 1.5" x 4"
Power Supply: The power supply is well designed but definitely
could use a few improvements... Most notably missing is a key switch.
For entertainment purposes, this means that in order to meet CDRH
requirements, the end projector must integrate a keyswitch and
power on delay itself... The other thing I noticed is that the modulation input
feels like a tacked on design feature rather than an integral portion
of the supply. The input is presented as a loose wire... I would have preferred
to see a BNC jack or something similar... I may not have noticed, but
it the modulation input was just too much of a stark contrast to the very
nice and well designed connector which attaches the head to the unit.
The dimensions of the power supply is 3" x 1.5" x 7"
Modulation
The unit supports TTL modulation at nominally faster than 10Khz,
Some quick patterns show that it works just fine...
Mounted in a conveniently spare scanhead system designed by ArcDevilz.
What this all means
This laser is a steal at any cost...
Reality check
Words are good, but what does it look like doing a beam show in real life?
http://photonlexicon.com/hostedcontent/sloc/Show1.avi [10MB MMJPEG AVI]
This clip was taken in my garage with the garage door open in broad daylight with the light streaming in!
More images available at: http://photonlexicon.com/gallery/album30
Fin.