Laser diode identification - Page 1
Forum section: electronics / repair

author: nccer
author_rank: Newbie
timestamp: May 20, 2024, 10:08:41 am
content: 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.

author: HiddenBear
author_rank: Newbie
timestamp: May 21, 2024, 06:14:50 pm
content: HelloThe 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

author: Gyro
author_rank: Super Contributor
timestamp: May 21, 2024, 06:47:41 pm
content: 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.

author: Twoflower
author_rank: Frequent Contributor
timestamp: May 21, 2024, 07:24:06 pm
content: The QR Microcode says: 1103773241Looks like a serial number.

author: fzabkar
author_rank: Super Contributor
timestamp: May 21, 2024, 08:17:51 pm
content: 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

author: perieanuo
author_rank: Frequent Contributor
timestamp: May 22, 2024, 07:34:56 am
content: 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.

author: nccer
author_rank: Newbie
timestamp: May 23, 2024, 02:57:06 pm
content: 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.

author: nccer
author_rank: Newbie
timestamp: May 23, 2024, 02:59:46 pm
content: 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.

author: nccer
author_rank: Newbie
timestamp: May 25, 2024, 02:48:38 am
content: How to align laser diode？

author: perieanuo
author_rank: Frequent Contributor
timestamp: May 27, 2024, 12:09:11 pm
content: 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

author: nccer
author_rank: Newbie
timestamp: May 27, 2024, 12:17:55 pm
content: 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.