488nm Direct Double MG Lab Laser System

Most recently i have not posted anything new. So i would like to show one of the recent laser systems Ive purchased 6 months back and hopefully share any helpful info on these just in case someone else needs help running them down the road.


I have plenty more systems to share with you guys its just hard to find the time with all the work you guys give me.:wave: Love you guys.:beer:

I Hope you enjoy this one.

Its a Melles Griot Solid State Direct Double "976nm" 488nm laser lab system..



Melles Griot 488nm System




This Is probably one of my most favorite Laser body designs. Just something about it that makes it look so cool.

This System iam showing off today is the Commercial version with the Lab controller. However there is also an OEM version that i also own as well. The only diffrence is the controller and more password protection on it.




Picture of the 4 Heads:

I have 4 of these heads at the moment left after selling off a few to freinds. Aswell as several lab style controllers as well as several OEM controllers. Alot of you guys already know that i got a bunch of new systems in recently and when i purchaced these Lab controllers there was a good amount of them on display for sale at the time so iam sure if you need one of these lab controller they will pop up from time to time. Or if you need one now i can get more just ask me. Anyway 2 of the heads are 20mW Rated,the 3rd is rated at 50mW and the 4th is a 20mW/10mW out the fiber, fiber laser. one of the 20mW heads is brand new. Only 2 minutes on the timer. I dint check the others yet but i can tell they are used. The 50mW head also looks nearly new aswell.




Picture of the head i will be showing in this thread is with the 20mW Model. However also the 50mW head i have is the same except the diode they are using is i think more powerful OR just a different brand. But the rest of the setup in the 50mW is the same as the 20mW i suppose. I wont open the cavity on the 50mW. For the fiber version its the same as the 20mW but has the fiber attached at the end and inside the box in the front is the fiber optics on a copper mount. I will share those systems at a later time if interested.




Here are a few picture of the head itself:










Inside of the Head:

Here are picture of within the head. The diode is fiber coupled butterfly style. Which is outside the cavity.:


Here is the datasheet for the diode:

http://www.lusterinc.com/UploadFile...d_withNarrow-Bandwidth_Grating_LC95A76ULR.pdf


It is^ an Incredible diode to say the least. To Create 488nm through direct doubling one of if not the hardest things to find is a Narrow Bandwidth diode That is able to hold at a stable wavelength with Little to no noise.

Your probably thinking that man thats only a 250mW single mode diode. What can that possible double.? Well lets just say Ive had this 20mW version Melles Griot laser hooked up under manual control and i got it doing over 70mW giving the diode only 600mA of currant. If i played with it more i probably could have gotten it up to 100mW. (Which since that try i have gotten it up to 86mW)

You guy's will see first hand in my next thread how important it is. The Slightest Noise in the output can mean No Lazing. Even a .2C difference can effect it. Direct doubling of 488nm or direct double for any matter is much harder then it looks.

Removing the cap off the cavity:


At another angel:


A very close look at the Non Linear crystal. Sorry i dont know what crystal kind it is as i cant find the info. My best guess from whatever i can read that its BBO:




5V 8A Power Supply Brick:

For the Commercial lab controllers The Power brick for these systems are a 5v 8A supply. I think they are made by XP-Power however there also appears to be re branded ones as well that are exactly the same "as it appears" as the XP-power branded ones but just have a different name on them. For now i made my own HD15 connector since the brick supply did not come with this type of connector on it already.

One thing i want to state in Bold is these Controller Especial the Commercial ones are Notorious in giving you an Start up error LED if your voltage input is not to its liking. If available you might have to tune your voltage input a little.
In most cases a standard Brick supply will work with the OEM controller. But it must be rated at least 8A. For the commercial controller its a hit or miss.

The 488nm heads i have seem to startup at ~1.5A-2.5A (Which is the TEC under the cavity quickly warming up so the startup time is reduced) but then settle down to ~ .8A-1A Pending power output. (The 50mW head is more.) However like i mentioned these controllers are also used with other heads aswell take for example the 473nm head that i have. IT will start up at 2.5A-3A and settle at ~2A. This is because it has 2 TEC's + the diode to run.

So stick with the 5V 8A brick i show in the post or use one of those Mini 5V 8A Power supply's i also show. (The Mini ones are much easier to tune in the voltage since they have a pot exposed. For the Brick kind you have to open them up and hope there is a Pot. The one i show bellow has a pot. I dint have to mess with it but i can tell you now it also does not work on all the controller i have for the commercial style)

So I guess what iam saying is if you get an Error dont rule out that the controller is bad. Although there is a Chance it could be as i know some of the ones that might come up are faulty i found that in most case the error is due to the voltage input not being to its liking.

Down Bellow I will list the LED ERROR CODE for you guys.



-The OEM controller is Much different then the lab commercial available controller. They both are the same when it comes to the core design but the OEM controller does not come with the on and off switches, interlock and key ignition built all in like the Commercial lab style does. You have to make your own control board for it. Both can be controller via RS-232. Via RS-232 you can power on the OEM controller without the need of making your own control board as well as do the same for the commercial lab controller. You will still need to make the proper connection though for the power input at the very least.


I made a Control board for the OEM style controller. Basically it turns the OEM version into the Commercial lab style setup. Minus the Key switch and the nice case. On some of the OEM controllers you might have to disable the Key Switch in order for you to activate the laser via RS-232. Some of them have had it done already but Ive noticed several needed me to disable it via RS-232.



Picture of My Custom Control Board for OEM Controller:

Here is my OEM Control board. I made it to have all the features as the commercial lab unit has and also added 2 common connectors/jack for Voltage input. So it makes it easier to use standard commonly available power supply bricks with a 2.5m jack. So it Can be either a DC brick at 5V or you can just use one of those cheap Power supply you find on ebay like i show behind the control board.:



Here it is in standby with just 5v going to the board. Since the OEM board doesnt have an on off switch i added one. It makes it eaiser to turn off or turn on the laser rather then having to unplug it everytime.:


Here it is when the laser/controller is fully ON. (There is a Jumper for the Interlock. if you pull the jumper out the LED will shut off showing you that the Interlock is disabled as a safety feature i added that rather then have a solid connection that always had the interlock connected):


Pending on the controller you have the OEM controller has a 45 second delay before you can do anything and the Comercial one is 5 seconds though i think its less then that..

TO Use my Control board its as simple as flip the main switch on, wait 45 seconds and then hit the laser emission button. TO turn the laser off just press the off button. Its that simple.

TO Use the Commercial controller You plug in your power brick turn the key from 12/6 oclock to 9/3 oclock and press the Green ON button. To turn the laser off press the red OFF button.

(Assuming you have the BNC Interlock connected on the controller):na:

Both controllers have Ramp up. Which you guys know by now iam a BIG Fan of this. (So big it can be a deal breaker for me)

Now if you dont want to make your own power brick for the lab style controller you can also use a controller setup like mine. In fact i made a different version as well for the commercial lab unit that only contains the proper connection for power. In other words:

The OEM Controller does not have all the buttons and interlock installed like the commercial lab controller has. SO for the OEM version when making the control power board you have to have the Emission button, the On/Off button and the Interlock bridged and disable the Key Switch via RS-232 in order for it to work.(Some controllers have the key switched already disabled so you might not have to do this) So if your making your own control board you will have to put all this on it.

THe Commercial lab unit already has all the buttons and the key switch and the interlock so all that is required is for you to have the proper voltage connections going into the controller on your control board if. This is why it only requires a 5v 8A supply input. So as mentioned if you dont want to make your own HD15 power brick supply you can make a board that has a HD15 Connector on it like i did for the output to connect to the lab controller and on the OTHER end have standard input voltage jacks or connectors to plug in a more standard DC 5v supply connector.

This board i made will be arriving in 10 days and i will post an update when it gets here. But it basically the same thing as the board i made above just minus all the buttons.

If you get one of these systems and would like a board from me just send me a Message and we can work something out.


Pinout for both Commercial and OEM Controller:
Note: Commercial Controller only needs power inputs for the pinout.

Here is the Pin-Out and what you need to do when making your control board for the HD15 connector for the OEM and Lab style controller. But please keep in mind the lab controller already has most of the pins already setup and only the power inputs are needed. THE OEM version needs all the pins setup.








RS-232 Setup Specs:

If you plain on running the system via RS-232 here is the specs.

A Standard DB9 to USB cable works just fine.

For the OEM Control Parameter Setting:

Baud Rate 19200
Parity None
Data Bits 8
Stop Bits 1
Flow Control None


For the Commercial lab controller I found that its:

Parameter Setting
Baud Rate 19200 on some and 9600 on others
Parity None
Data Bits 8
Stop Bits 1
Flow Control None


Commands for RS-232:

I USE PUTTY for my serial Commander.!


Here are some of the commands.:

-Issue a “set” command-

Eliminate the [?] from the command. For example:

LAS:MODE 0
Will place the laser system in ACC mode.


-Issue a “read” command-

Include a ? after the command. For example:

LAS:MODE?
Will return a 0 if the laser is in ACC mode or a 1 if
the laser is in APC mode.


-Set or read laser output power (mW) - LASOW:REF[?]

-Set or read laser diode current set point (mA) - LAS:CURR:REF[?]

-Set or read keyswitch mode - KS[?]
0 = Keyswitch turn laser on
and off
2 = Keyswitch acts as safety
interlock. Laser must be
turned on remotely or via
RS-232.

-Set or read laser state - LAS:STAT[?]
0 = Turn laser off
1 = Turn laser on. The laser
will start after a 5 second
safety delay.

-Turn laser and TEC's off in case of emergency - ABOR

-Set or read laser TEC status - LTEC:STAT[?]
0 = TECs on
1 = TECs ramping
2 = TECs and laser off

-Set or read laser control mode - LAS:MODE[?]
0 = Automatic Current
Control (ACC)
1 = Automatic Power

-Read error code log - ERR:CODE:LOG

-Clear error condition - *CLR

Those are basically all the commands i know and that you need to run the laser via RS-232. If you need more info just ask and i will try to help to the best i can.

Now brings me to the controls. Not all the controls work. Well at least on my systems. Some are password protected. More so on the OEM version, but really the commercial version aswell is just about the same with pasword protections.

I fully understand why they do that. Its so people dont mess up the settings and kill a $20K Laser system. Keep in mind thats around what these go for Fully loaded New.

However 1 thing really gets to me and i have yet to figure it out. Iam pulling my hair out at this point. The laser head stores all the saved data within. So once you set the power you want via RS-232 you dont have to keep going back to reset it to that everytime you turn the system on. The heads where all set to 5mW. The Trouble iam having with these specific heads is It will accept my command for changing the power, it will show that it accepted it just fine however the power will not change. I think i must be doing something wrong OR the Power command i have is not the correct one for these 488nm heads. As in it might be reading it fine and accepting it but its not the correct command.

Please note that this power command works on 2 other Melles Griot systems i have that use this type of controller so i just dont get it.

Does anyone know any more power commands for Melles Griot lasers that i can try.? This would mean the world to me.

Melles Griot does not want to help me since there first and only question is what is the name of your company when you contact them. If you dont have a company to provide them where they feel its worth there time then forget getting any help out of them.. Flat out they did not want to help me past 1 email and i think i was lucky i even got a response.:undecided:

Iam a Big fan of Melles Griot lasers. But they are not helpful at all if you try to contact them for info. I Understand that iam not some multi million company that is going to spend millions with them, but still there should be some support for just a regular user like us. You might get lucky though. Catch someone on a good day and they help. IDK I dont like that they do this. Iam not the only one that would say they dont want to help us. Others have tried as well even some big time laser guys have tried in the past with similar results in help i got. Iam sure if i bought the systems brand new directly from them it would be a different store but if you come across a MG system surplus your pretty much on your own in finding info Unless like mentioned you get lucky and catch one of the workers at MG on a Good day and are willing to give you the info. Dont hold your breath though.

Now iam not pointing the finger at only Melles Griot. Several other laser company's do the same as well as some IC company's Ive contacted in the past. With Melles Griot i wrote a very nice write up to them which there response was what is the name of your company.? I told them i dont have one and if they could kindly help me with about 5 minutes of there time for info and they never re responded to me. Very Sad and makes me upset a little because i own nearly every model of there solid state systems and iam very happy with the lasers but there help service Stinks.! :undecided:

I hope one day this changes.

Anyway so if anyone has any power commands for me to try please post them. I would be grateful 10 Fold.:beer:

TO be clear again the issue iam having is it will accept my command,show that it changed the power but the power does not increase.

Other Melles griot laser change power that i have. These heads dont though and i dont get it.

There is several other things that i think could be the problem but i first want to try some other command that maybe some of you guys might know first as the Power is set to 5mW and its putting out that.

I know that its not password protected for sure as when it is it tells you its password protected. Iam hoping its just a different power control command.

So Far the 2 command i know for Power for Melles Griot RS-232 power commands are:

LASOW:REF
&
LASOW

I can put in the power like so and it takes the command both ways:

LASOW:REF 20
LASOW:REF 20.00

But it wont change the power.Any idea.?



The Inside of the controller:
Note: Its missing the main processor because i was doing a repair on this controller.

Note 2: If your controller is NOT Matched to your head it can also give you an Error. (It is very Hard to find a Matching head and controller at this point)





ERROR LED Blinking Codes:

Note: Count the Amount of Flashes and line it up with the error its giving.




Finally a few Beam Shots:












Final Thoughts:

These Melles Griot systems are very Nice.

It stays in TEMP00 for what it appears to the eye. Solid. Never leaves this mode. Doesn't flicker or anything. Just a Nice clean Dot. There appears to be Wings coming off the dot (Like a LPC-826 red 660nm diode has) I cant make it out if its due to optics or actually in the output But its faint.

Divergence with my measurements is at about 1mRad or less.

The Diameter of the beam is Incredible. I measure at the aperture at about 1mm. Spec sheet says .70 +/- .05mm.

There is Practically no heat that comes off the head. Though i still would put it on a sink just for safe measures.

For power output i can only get 5mW out of the head since thats the preset and i dont know why i cannot change the power yet. Based on the 5mW the power is Solid.

Under manual control using a Laser diode and TEC controller (Model SDL-820)
Iam able to get >80mW Stable out of the 20mW heads with only 600mA going to the diode..:wave:

With the Lab Controller or the OEM controller the 20mW heads are Capped to MAX out at 25mW RATED. THe 50mW is Capped at 55mW.

So lets hope soon i can figure out the command that will make the heads work with APC with the controllers and allow me to change power like i can with other Melles Griot systems i have. Iam pretty sure its something to do with the command issue iam giving it.

If i cant figure it out then ill make a driver of my own to run these heads. In fact it would be pretty cool to do this either way. Maybe:shhh:


I have not had much time with the system as i have quit a few different systems that i have been trying to get a write up done on them to post.

For these Heads the covers on them have a few dings in them. Well 2 of them do. The other 2 heads are mint. I plain on fully restoring the heads with my twist added to them with a new aluminum caps. Which i already got a quote on to do a custom top and its not that bad. So Expect to see a RE-Design on the caps soon.
I think you guys will like the caps i designed. But no spoiler yet.:na:

I have some videos aswell of the laser in action etc. I will be uploading them in the next couple of days for you guys.:wave:


Anyway hope you guys found this interesting. Cant wait to share the next system with you guys. Its a True Jaw Dropper. I promise. :eg:​