Laser diode module coherent 10-12v 780-1100nm CW  - Page 1
Forum section: electronics / repair

author: ciclonite
author_rank: Contributor
timestamp: April 08, 2023, 06:16:18 am
content: I have in my possession a used laser module 10-12V in CW 780-1100nm and I need some help. Firstly, I am aware of all the risks associated with operating lasers (including invisible sources and related refractions), and that the powers involved are very high, which is why I plan to work remotely using a camera. Secondly, in my jurisdiction, such modules are not illegal. Thirdly, the operations will be carried out with the minimum excitation power of the laser. Getting to the point, upon disassembling the module, I noticed that 2 front lenses had come off and I wanted to reposition them. However, I especially needed help since I do not have the technical specifications of the laser, to understand how to perform a test at minimum excitation power and potentially calculate it without having the specifications. Additionally, I needed help to reposition the lenses. Thank you.

author: jonpaul
author_rank: Super Contributor
timestamp: April 08, 2023, 12:36:37 pm
content: You haven't only an incomplete part od0f a complex system.power supply ,controllers, optical head, ancillary, etc.a 300 W CW laser is very dangerous. Many injuries and accidents even in professional laboratory.Doubt if you can work remotely with a camera.please read about laser safety, obtain properly rated goggles for the wavelength and powers anticipated.Check up your health and fire insurance policy for coverage.It may need water cooling or special gas supplies.below a threshold power, no lasing will be possibleThe lenses are perhaps beam collimators or expander.I hope your project will proceedure safely.Jon

author: ciclonite
author_rank: Contributor
timestamp: April 08, 2023, 08:30:23 pm
content: Thank you Jon for your response and I want to reassure you that I have already planned to use protective glasses and all necessary precautions. I have already worked with a 650W ND-YAG laser and now I would like to learn more about this module. I have seen from your posts that you are very knowledgeable and I would like to ask you some questions. Leaving aside the optical part for the moment, can a CW laser diode driver be replaced with a laboratory power supply just to check if the laser module is working? If I set it, for example, to 10.5V at 3A, can I verify the correct operation of the laser diode? With this power, can I temporarily avoid liquid cooling? Thank you very much.

author: jonpaul
author_rank: Super Contributor
timestamp: April 08, 2023, 11:02:47 pm
content: Rebonjour Cher Monsieur, I am familiar with smaller laser diodes like 0.5..50 mw but this may apply to your device.it is unclear whether you are trying to run the bare laser diode, or if the apparatus has a self contained driver module, requiring just a DC power input.In the former case I can comment..A laser diode driver is a regulated current source, with several feedback and protection features. Junction température, output light, current are sensed.The junction is very susceptible to transients, even a sub microseconds over voltage damages or destroys the junction. ESD handling and TAZ shunt protection is used.A lab power supply voltage source will perhaps produce a momentary lase but is sure to damage or destroy the junction.Without proper cooling the junction temperature will rise rapidly.Finally the laser diode has a threshold power or current where lasing action begins very abruptly.The behaviors optically and electronic are totally different than other types of lasers.If you can identify the device you may find information from the manufacturer.If it's impossible to do that, than you could test with a current source power supply with transient protections.Still suggest you obtain the classic text "laser safety" by Henderson and Schulmesiter, an expensive but necessary book.Bon chanceJon

author: ciclonite
author_rank: Contributor
timestamp: April 10, 2023, 01:46:07 pm
content: Thank you Jon for your patience. I am trying to run the device containing the driver module (thus the module with the driver and related optics) work. I am attaching photos for clarity. I purchased a Lumina power supply (on a friend's advice) LDD-1000-40-24-RS-LR, max 40A @ 24V, here is the manualhttps://luminapower.com/wp-content/uploads/2015/05/ldd_600_1000_1500_manual.pdf. I can easily control it in analog and it has many interesting functions. At the same time, I contacted the manufacturer of the model, but I doubt they will respond. Thank you also for the book recommendation, I just purchased it in Kindle format. I am attaching some photos, let me know what you think. Thank you very much.

author: jonpaul
author_rank: Super Contributor
timestamp: April 10, 2023, 02:38:09 pm
content: Hello again, I am sure that these decades old units were scrapped as defective, optically or electronically.For the DC power, the Lumina seems OK but be sure to use static ESD precautions and TAZ.You should arrange for water cooling system with appropriate flow speed and volume for the anticiped power dissipation, estimate that all DC power will be dissipated, eg zero efficiency.Do you have the beam dump, black room and kW rated infrared beam calorimiter?what is your ultimate goal, application?Bon courageJonPS your image storage server imgbb is infested with obtrusive ads. Use Dropbox, etc.Send me a PM for further details

author: RoGeorge
author_rank: Super Contributor
timestamp: April 10, 2023, 02:39:03 pm
content: Quote from: ciclonite on April 08, 2023, 08:30:23 pmI know very little about lasers, and nothing about the particular model you are testing. What I know as a thumb rule is power laser diodes have an internally photodiode to measure the power output. The photodiode is usually in a closed feedback loop that regulates the power for the laser diode. That is a high speed regulating loop, so I think if you plan to automate a control loop using an external power supply, it won't work. Lab power supplies doesn't respond that fast.I wouldn't dare to power the laser diode alone either, disregarding the internal photodiode. If your plan is to set a constant current in the lab power supply, beware most lab power supply have big electrolytic capacitors at their outputs. This means, if you set your power supply for, say 5V/10mA max, the output capacitor will be at 5V, and when you connect the diode, they will instantly discharge into the laser diode, with many amps of instant current. Such big discharge current might damage the laser diode long before the lab supply will start to deliver regulated 10mA. The output capacitors in many power supplies are usually outside of the feedback loop that was supposed to regulate those 10mA. It is like charging a few thousands uF at 5V, then remove them and connect them in parallel with the diode.I won't power the diode without proper cooling either. That's asking for troubles. Why risking that?Even if you successfully improvise, and eventually start the laser and check the diode is working, how do you know you didn't inflict any damage while checking? The diode can melt only partially, then later, when properly cooled and powered, the damaged diode will deliver less power than it should.I'll wait 1-2 days for the manufacturer's tech support to reply. I think they will reply. If they don't, write them again, or make a phone call to marketing/sales, and ask to redirect you to tech support.I'd be curios to learn how you tested, in the end, and how it worked.Good luck with it!

author: ciclonite
author_rank: Contributor
timestamp: April 10, 2023, 09:25:27 pm
content: Thank you all for your responses, after discussing with you, I will wait for the Lumina power supply to arrive before attempting anything. Additionally, I am already designing the flange that will be installed for liquid cooling. I have disassembled that connector and posted a video on YouTube, I've never seen a similar model. I am attaching the YouTube video in case anyone is interested. I will update the post when there is news regarding it. Thank you very much!https://youtube.com/shorts/46x1C_b2Dp4

author: ciclonite
author_rank: Contributor
timestamp: April 14, 2023, 10:37:11 pm
content: Finally i have got the specs for the laser:Center Wavelength nm 976Wavelength Tolerance nm ±3Output Power 270WSpectral Width (FWHM) nm <5Slope Efficiency W/A >7.5Fiber ConnectorFixed Pigtail FiberFiber Core Diameter µm 225/240Numerical Aperture NA 0.22Power Conversion Efficiency % >51Threshold Current (ITH) A <3Operating Current (IOP) A <40Operating Voltage (UOP) V <15So i Plan to Power the module with 3A current.The problem Is the fixed pigtail connector...Simeone can explain how can i connect the delivery fiber to this fixed pigtail? Thanks

author: jonpaul
author_rank: Super Contributor
timestamp: April 15, 2023, 12:29:09 am
content: see the many books and papers on laser to fiber interface.Most optics books will cover it a bitjon

author: ciclonite
author_rank: Contributor
timestamp: April 15, 2023, 06:33:14 am
content: Quote from: jonpaul on April 15, 2023, 12:29:09 amHello Jon, thank you for your response. I looked for information on this Fixed Pigtail Fiber, but I couldn't find anything on this type of connector related to the field of high power lasers. I only find pigtail connectors for optical fibers used for signal transport. Could you give me an indication of which book I could look for? I am attaching some photos.https://workdrive.zohopublic.eu/external/2742cc69e78ab88890beaa08167e387db826acfedb0b4ed9d9dbc0b308a5b85fhttps://workdrive.zohopublic.eu/external/fb6d05a4fe315f756157865da46d9f140607c61d17371f871485cf83bcf7fb9fThanks.

author: jonpaul
author_rank: Super Contributor
timestamp: April 15, 2023, 11:53:57 am
content: pigtail: cut end of commercial fiber, no technical issues.j

author: jonpaul
author_rank: Super Contributor
timestamp: April 15, 2023, 12:28:41 pm
content: Your lasers may have been intended for illumination or chemical activation via a low cost fiber.Thus the NA, modes, coherence and other specs of the output were optimized for such use.There is a tradeoff in such beam characteristics vis a vis the power,If you can adapt your use to the type of beam and inteface your project could work.If you intend to have a coherent collimated beam, perhaps not.Study the optics of lasers in general, many text books and papers.Jon