Prelim Review of New DealExtreme 100mw Green Module -
When I first got this, the package was badly mangled, so when I noticed while unwrapping the module that the driver
was not firmly attached, and was moving in relation to the module, I thought to myself - "OMG, did they break-off the diode pins in transit???" :huh:
But when I got it unwrapped and examined it closely, it turns out that the driver was free-spinning because the small piece to which it was attached had not been screwed-in all the way!
It turned-out (a major benefit for this DX design),
this module consists of several modular components that are threaded, and can easily be disassembled - Cool! :yh:
Initial impression is that the 100mw one is likely a 200mw one that did not pass Q/C at full strength, given that I found at least one issue with the unit that could potentially reduce output power.
Both the overall length, and the individual length of the assembled brass module and driver board, are all
slightly shorter than my O-Like. Only size issue is that fat resistor (yes, it
DOES have that), one end of which is sitting on top of the regulator IC, and extends out slightly farther than the outer edge of the brass module,
so fitting in a tight pen host might cause a problem.
The module itself can be easily disassembled into 3 threaded modular components, the driver/lasing module, the beam expander/containment module, and the collimator/focusing lens module. I will describe each of these in turn.
(Note - examination aided by my 30x jeweler's loupe, great for looking at tiny SMD designs, DPSS crystals, diode innards, etc.! :yh
DRIVER:
The driver, even though shorter, appears to be possibly
superior in design to my O-Like. It has an 8 pin regulator IC that is controlling
a separate driver transistor. The big resistor (if I am decoding it correctly) appears to be a 0.33 ohm, with 1% precision.
Examination of the driver under magnification, however, reveals rather poor soldering, with some poor/barely attached solder connections, some semi-cold soldering joints, and splatter all over the board.
Also excess flux all over and bubbling-up from some joints - appears board was not cleaned/de-fluxed after soldering?
Pushbutton switch takes a lot of pressure to depress (possible problem because of the way the driver board is mounted - see below). Two color-coded leads. Black lead connects to back/center of driver, making is appear fairly easy to replace with a spring. Red lead attaches towards front of board, has clear plastic goo insulating where it attaches - rather strange, as red lead connects to case pin on LD!
One corner of board barely touching back of brass base, other corner actually has slight gap between it and base. Unlike the O-Like (which has glue on both sides holding the driver board securely to the module),
the driver board is ONLY supported / attached to module via the laser diode pins!
DIODE/DPSS MODULE:
Diode has 3 pins, in a flat-based triangle arrangement, with the peak of the triangle being case ground. Hard to tell with stuff in the way, but based on pin spacing,
diode also appears NOTICABLY larger than the one on my O-Like. All 3 pins are soldered to the driver. Diode appears to be held in place from the back with something similar-looking to a lens nut (but deeper), with notches on each side.
Outside visible portion of diode/DPSS module is surprisingly short - only about 4mm (about 1/2 that of the O-Like). Majority of it extends inside, and has threads which screw it into the next module.
Inside the diode/DPSS base, it is apparent that the diode is a
sizable open-can variety. There is an extended C-shaped piece of metal about 3mm tall glued to the top of this module, which contains the crystals. It has a deep notch to hold the crystals, which does not extend quite to the top, but opens-up near the top inside of the piece.
The SHG crystal is rectangular and long. The end is square, and slightly less than half the width of the notch. It is pressed into one corner of the notch, so that two sides of it are heat sinked to the metal, and held in place with a large glob of white glue-like substance (It is not possible to see the vandate crystal, or whether the two are one piece, because of all of this glue). The end of the crystal extends slightly past the top of the notch, and thus is not heat-sinked.
There appears to be a defect or foreign substance on the coated face of the crystal! :wtf: Examination revealed this to be a streak of that white glue, stuck to the face of the crystal - apparently they applied this stuff too liberally / sloppily! :tsk:
Luckily, closer inspection revealed that this streak of glue was along the same horizontal direction as the laser diode die, but was located vertically aligned with the base
BELOW the die on the laser, and so appears to
be out of the beam path - Whew!
(Although I am curious if this substance on the crystal face could still cause problems?:undecided
The side of the crystal has a rough texture, white and with what appeared like veins, similar to what a piece of quartz rock (not crystal) looks like. Looking inside the crystal from the top, typically appears sections light and dark green, but occasionally dark violet, depending on the angle and lighting. One thing I did notice was angled lines of dark green (hopefully not fractures inside the crystal!), perhaps someone more familiar with these crystals can let me know if these lines are normal?
BEAM EXPANDER/CONTAINMENT MODULE:
This module wraps-around and "contains" the DPSS section of the module below. The visible outside portion of this module is about 9mm in length. It is closed and thick at the top, with a narrow "light tunnel" drilled through it. (It is hard to tell with the attached piece, but it appears this may extend out past the top).
Glued to the top of the module is a piece similar in shape to a brass spacer, but wider, and about 4mm thick, and which appears to contain a negative lens (viewing through both the magnifier and this lens results in focusing at infinity), presumably used as a beam expander.
Unfortunately, this piece is glued off-center, such that the expander lens and the light tunnel below do not line-up fully, blocking part of the path below. Hopefully this is not blocking part of the beam! (This may be why this unit was rated at 100mw?) Not sure if this is fixable or not.
COLLIMATOR/FOCUSING LENS MODULE
This is the longest of the brass sections, with a base extending about 12mm long, which then narrows, and then extends about 1cm, about the last 7mm of which is externally threaded. There is a long, black spacer inside of the threaded portion behind the lens. While the end of the module is narrower, surprisingly,
the lens itself appears to be wider than the O-Like!
The lens nut has two shallow "dimples" rather than the more traditional notches. The lens appears to be located as far out as it could be, and the aforementioned spacer prevents it from going any deeper. The lens appears to be designed to just collimate/focus the beam from the beam expander,
and NOT to support adjustable focusing.
There was some theorizing before about the purpose of these external threads. Given the thickness of the metal at the end, the fairly small outside surface area of the (heat generating) diode/DPSS module, that this appears to have been designed to use all three screw-on pieces of brass as one big heat sink, (carrying the heat forward and away from the LD), and finally the fact that this is not some hobbyist "mod", but was designed from the get-go for high power - IMHO all of this point to the use of these threads to mount to dissipate heat, ether to a metal case, or a supplemental heat sink, one that could press against the flat lip below the base of the threads, and perhaps even wrap-around the module.
This might also eliminate the need for a set screw. You could also build a pretty neat-looking "screw on" heat sink accessory for such a laser - a "screw-on silencer" design!
BTW, styropyro, you said the pics on DX looked like the modable ones you pulled out of the True 5's. Did they also come apart like this one? Does it have the same resistor & colors - Black Orange Orange Silver Brown? My description should be detailed enough for you to be able to tell us if it is indeed the same driver and/or module you were referring to?
After detailed examination of the innards and hours of work, my PC crashed while I was finishing this, vaporizing most of my review! :banghead:
Arrrgh! So beware most of the measurements are a bit rough, and from memory. Likewise, don't shoot me if I made any mistakes - I wanted to get this up for everybody as quickly as possible, and plan on editing / adding to / improving it afterwards.
Overall, I would say that while the construction quality was a bit lacking (and may impede the performance of the unit), I think the physical design is better than my O-Like, and both the driver and diode also appear to be heavier-duty than my O-Like one. So a mixed bag, whether these stronger components actually follow-through with stronger results during testing will determine if I rate this one thumbs-up or down.
Finally, I haven't had a chance to "flame-test" this guy yet (I do not yet have a proper host, batteries, or an LPM). I'm also thinking that trying to juggle two batteries, test wires, and a bare high-power unfiltered module, indoors and at night without goggles, is
PROBABLY not the best idea! Once I can find / get access to the right stuff, I will see about posting some performance #'s on this guy!