Laser optical pickup unit hacking

Dear all

Laser optical pickup units that are used in CD / DVD and BlueRay players to read the disc are amazing pieces of engineering with built in lasers, optical stages, filters and mirrors. These small units, that can be found in almost any electronics dumpster, are a perfect starting point for building amazing scientific instruments. Let’s bring some ideas and people together here.

Almost 10 years ago, together with friends from hackteria / Berlin / TUM Munich, we started working on building a DIY Laser Tweezer (optical trap) built only from a DVD pickup and a webcam. We based on the paper “Single-cell isolation using a DVD optical pickup” by a researcher at Colorado School of Mines (and now Process Engineer at Intel Corporation). It was fun playing with the laser unit and we finally got it working.


http://www.gaudi.ch/GaudiLabs/?page_id=578
https://hackteria.org/wiki/DIY_Laser_tweezer,_cell_trap,_oligo_synthesis

I later started to build a laser scanner using a Blue Ray pickup as I wanted to now more on how the built in sensors can be used. Based on the research by two brothers from Madrid (Spain) building a PCB printer from the laser head, we almost completely reverse engineered the PHR-803T pickup that is commonly used in the Xbox.

http://www.gaudi.ch/GaudiLabs/?page_id=652

Over the years I met many more interesting people hacking these laser pickup units to do amazing scientific devices and experiments with it:

There is “the professor of laser optical pickup” hacking, now at Technical University of Denmark | DTU · Department of Micro- and Nanotechnology. He built the famous high speed atomic force microscope (HSAFM) based on an optical pickup unit and countless other incredible things. His latest feat, a Micro/Nanoscale 3D Printing device using a hacked Blu-ray Player.

Then I got contacted by an engineering student at Lawrence Tech in Southfield, Michigan. He built himself an apparatus to micro 3D scan. He took high resolution 3D scanns of wasps and other critters.

And then there is a PhD student in Shiraz who built a working optical coherent tomography (OCT) that can take 3D images in tissues. He also built various Michelson interferometers with the use of DVD optic component and printers.

So I thought it’s time that we all get a place to start discussing (using the ReSeq category for now as I think it fits best). I did not put names here and will invite you all individually by mail to this thread. I am happy if you join and tell us more about your work.

Urs

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Hey Urs,

Thanks for the shoutout and starting this thread. (I’m the Lawrence tech engineering student). I like the tagline of using blu-ray (PS3 KES400a) for doing micro 3D scans, but people might be disappointed to hear that the optics of the player were actually not used for that project, but instead used two assemblies and a USB microscope as the imaging device. It did, however, use the micro stepper motor normally used for changing layers in the blu-ray as a little mini Z axis. You can find that project detailed in an instructables here and a sequel using a 3D printer on hackaday here

(post continued due to new user image and link restrictions)

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pt2

The most data I actually got using the optical pickup unit itself is much less impressive. Here it is:

comparison
this 20 by 20 pixels image was obtained quite jankily using just blu-ray parts, including all the motors, except instead of using the native quad photodiodes I literally drilled a hole in the assembly where they used to go and stuck a naked single photodiode in.

I put that signal in a raspberry pi and used the motors to cycle through until I got the strongest image, which was then a greyscale value. I actually think this method has potential in its simplicity but absolutely does not compare to using the quad photodiodes in their native configuration.

Someone much further ahead of me in that regard is an electrical engineering student, Sam Zeloof, who posts things on twitter: https://twitter.com/szeloof/status/1157392806551412736

He has really solid almost overengineered drivers for I think 3 different blu-ray players, as well as all the proper lab tools (fast XYZ table for instance) to go along with it. While I do other stuff I’m basically waiting for him to finish his research so I can pick up where he left off, lol.

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Yes, these pickups are great (and cheap) components for a variety of applications, not just imaging. For example in this image you can see two interferometers build using the lens actor of a CD pickup to move a mirror.

Best,

Teide

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Hi Urs, I’m potentially interested. If you wanna do anything involving AFM or lens-free microscopy then count me in.

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Hi @WayneWayneHello and welcome to the forum. I also think replacing the built in photo-diodes is a good idea in some cases. I used to do it too. Also from what I understand the built in photo-diodes are super fast but not very sensitive / need a lot of amplification.

And welcome @tboysen and @jmarkham to the thread - I thought this might be interesting for you too. These pickup-heads are built just like tiny HiSeqs :slight_smile: And combining them with microfluidics opens up even more possibilities.

Here a nice video :wink:

And the slides that go with it:


Urs

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Dear all
thank you for invite me to thread.
my name is mojtaba ebrahimi. I am a PhD student of optic and laser physic at the University of Shiraz. My thesis topic is point of care(POC) device.And my focus is on building an optical coherent tomography(OCT) device by modify optical pickup(OPU). This device is used for 3D imaging of tissues as well as fluid cells.I hope i can complete my plan with your helps. And build a reliable point of care device. And share information and experiences with you.
best,
mojtaba

Dear all,

It’s very nice to see many people discuss about implementing the OPU for fun and research!

The review article “Hacking CD/DVD/Blu-ray for Biosensing”
https://pubs.acs.org/doi/abs/10.1021/acssensors.8b00340

provided 3 different Blu-ray/HD-DVD/DVD/CD OPU drivers here:
https://drive.google.com/open?id=1G-EXtJZ3PajhJJ8Ppi6O5qTkXGD7UWDV

Recently we have a fun development “OPU based macro 3D printer”:
https//drive.google.com/open?id=1eDlcW-9staGzVLA70D-VH-P8HC9bL14X

Which is a simplified version of the OPU based Micro/Nano 3D printer:
https//backend.orbit.dtu.dk/ws/portalfiles/portal/197546033/HD_DVD_Based_Microscale_3D_Printer.pdf

This start-up company is using a modified Blu-ray drive I developed with Danish collaborator back in 2013:
https//biologictube.dk/video/38262420/blusense

I am very interested in exploring more bio-related application… would like to learn from you guys :smiley:

Cheers,

Edwin

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Hi Gaudi,

I am very interested in DVD based OCT, but somehow I can not find the correct literature. Is there any keywords for me to search?

Edwin

Hi Edwin
I suggest two ways to make oct based on dvd.
Correction of opu to a Michelson interferometer. You can follow the procedure in this article.
https://www.sciencedirect.com/science/article/abs/pii/S0143816618307814
After constructing an interferometer you should use a SLD light source instead of a laser.
And then you need a spectrometer. That you can make it. You can follow the procedure in this article or follow the link below to create a spectrometer.
osapublishing.org/boe/abstract.cfm?uri=boe-9-3-1232
“gaudi.ch/GaudiLabs/?page_id=328”
You can find this “scanner” in the works of friends mentioned above.
best,
mojtaba

Great! Thank you very much!! :grinning: :grinning: :grinning:

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Hello all

This is a very interesting topic. I am an artist based in Zurich, in regards of the massive availability of those lazors this thread is super exciting.

Even for making art. These are other possibilities to work with.

@wayne and @all pls feel free to invite people to join.

Best

M

Gesendet von Yahoo Mail auf Android

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Hey all,

I am very much interested in playing around with and building stuff based on laser optical pickups and the mechanics around them. I have been meaning to for a long time and I guess this is a great time to get started - and especially in good company too! I do have some burner pickups but also i do have a box of more than 100 drive mechanics with pickups waiting to come to use… I guess it is probably a lot easier to get specific models that we do have knowledge about already and perhaps even documentation for and can improve our understanding of together though!

Cheers,
Bengt

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Agreed. Documentation and drivers are a key resource. I don’t have any idea what the best choice is or how much difference there is between the different kinds.

Hello Edwin,

I had started working on OPU 6 months back, inspired from your paper and work you have done till now.

Right now, I have a project I am working on for the detection of COVID 19 using CD DVD technology. I want to use the opu to scan the surface of a optical disc, simultaneously autofocusing it and while it happens I want to get the reflectance data from the PDIC sensor in real time to generate an image of the disc.

Instead of using xy axis sled I thought why not use the servo motor setup of the CD DVD player itself and scan the surface using either CLV architecture or CAV architecture. ( http://www.cdfs.com/cdfs-glos-optical-disc-drive.html )

Then use the reflectance data to make a gray scale image.

Hope you can help me out with this.

Welcome to the forum @Gourav . I like your video explaining the biological principle, nice hand’s on part. Let me share it with the group:

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Hi Gourav,

You can gte the reflectance data from the RF signal of the PDIC. I tried to use servo motor with high resolution feedback to replace the original motor on the drive, but not successful. The DVD from control IC some how changing the speed while locking the laser to the disc.

I am wondering if this technique is evaluated without spinning?

Cheers,

Edwin

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Thank you.
Yes, I faced similar problems, so right now I have changed my method a bit.
What I am trying to d right now is without dismantling the original parts from a DVD player I will try to use a small software to control the speed of the scan and give the logical address of sectors to scan a particular area. Because I have the scan path trajectory equation and a constant speed of scan I can know at what position is the laser head at any point of time and get the reflectance data accordingly and use it to plot the image.

Now the major problem is Software. I don’t have the necessary expertise to make software to do what I have proposed.

Hi Gourav,
I may be able to access the RF signal on the DVD while the OPU laser is locked on the data tracks. Because I can ask a Blu-ray/DVD producer in Taiwan I collaborated. Do you know what would be the signal change ratio? 10% less?

Cheers,
Edwin

Great, it would be great if that can be done. It would solve a lot of my problems.

Regarding the drop in the signal I dont have any experimental data of my own but this is what I have got from some research papers. This data is shown for a reference gray scale pattern which was kept on the sc while scanning.

[Potyrailo R A, Morris W G, Leach A M, Sivavec T M, Wisnudel M B and Boyette S 2006 Analog signal acquisition from computer optical disk drives for quantitative chemical sensing Anal. Chem. 78 5893–9

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