Laser diode identification

[nccer]

Hello, I got problem with damaged laser diode. I want to replace but I am not sure what to buy. I am repairing Olympus OLS4100 microscope, and its laser diode is damaged. I want to know where to buy the same model of diode. I only know its wavelength is 405nm now, but I don't know its power.

[HiddenBear]

Hello

The microscope is quite advance I must admite, for sure a laboratory tech.Luckyly Olympus is a well knowed firm, so in the first place I would send a mail to there tech support. If I'm correct there should be a plate on the backside of the microscope with a manufacturing number and a telephone one to there tech support. Zeiss's confocal microscopes have something like that, not sure about Olympus ones.  I'm assuming that You are working for a laboratory so you should have access to a university mail. I would ask send them a messenge that you have some questions about the laser that is used for the laser in the pretext of adding this information to a article You are currently working on.

But I would ask myself if the laser diode is damaged for sure? Got You any communications from the software that the manufacturer provides that the laser diode is damage? It's a vital question because laser diodes are precisely engineered for aplication that they are used in. You could buy a laser diode with the same wavelenght, but as you well pointed not knowing the power of this one. Droping a random one that fits the size and wavelenght is not a solution, because it could damage the sensible electronics of the microscope or just not work.

Also a good question if the microspoce have a valid warranty, if yes I would contact the service. Hoping that's better than the Zeiss one xD. Maybe it's a ~70/140$ worth element, but the microscope cost ~70 000 $ (here in Poland when I asked my doctor a few months ago for a similar model). I personalny wouldn't take a risk of fixing it myself not fully knowing the electronic scheme of the circuit or all the diode parameters.

Thats my view on this topic

[Gyro]

Regarding the identification, can you not take an uncompressed image and read the QR code? There are too many compression artifacts on the image that you posted.

[Twoflower]

The QR Microcode says: 1103773241

Looks like a serial number.

[fzabkar]

I examined a few datasheets and it seems that the efficiency is about 20%. Therefore, you should be able to estimate the power output by measuring the operating voltage and current, and then dividing the power by 5.

I notice that there are some diodes with an additional monitor photodiode, eg ...

https://seltokphotonics.com/upload/iblock/0da/0dafefd3d61917cf79272576d3a83ff5.pdf

[perieanuo]

same opinion here, just check if you need a simple emissive diode or one with power detection, then dig for the power you need.
if it's with diode feedback, a simple one won't do. you can just check if the second diode for detection have some electronics behind, a simple resistive measurement will point that.

[nccer]

 Hi everyone, I have tear down the Olympus ols4100 and I found that the Olympus laser circuit has its own light intensity detection feedback circuit, so I randomly changed a 5mw 405 laser, the machine works well.
But now I have another problem, because I moved the position of the diode when I disassembled, now the light path can not be aligned, I still do not know how to adjust. I'll add pictures in a later update.

[nccer]

Thank you for your advice. Actually I have already reached Olympus, they give me an offer of more than $10k. I can’t afford it.

[nccer]

How to align laser diode？

[perieanuo]

dunno your details, but aligning the focus point or the x/y target coordinates? i manufactured focused lasers and setting laser focus point using prismatic systems by pressing the laser diode until the focus point was where it should be, x/y is simpler. try some trial and error maybe

[nccer]

Thank you for your reply. I will upload details when I get time.
I think the light path is like this. When I remove the diode I accidentally remove it with focusing lens together.
So I have to align the laser diode and focusing lens. Together.
I think the screw holes inside the red circle are the key, but because they are all held in place by glue, I dare not destructively remove them now.