DVD Drives Turned Into Microscopes

With the advent of streaming services, plenty of people are opting to forego the collection of physical media. In turn, there are now a lot of optical drives sitting unused in parts bins and old computers. If you’d like something useful to do with this now-obsolete technology, you can have a try at turning one into a laser microscope.

This build requires two DVD pickups. By scanning once horizontally and once vertically and measuring the returning light from the DVD laser, an image can be created. For this build, the second pickup is used to move the object itself. The entire device is controlled by an Analog Discovery 2, although this principle could be ported to other microcontroller platforms. Thanks to the extremely fine laser in a DVD and the precise movements of the motors found in the control machinery, the images obtained using this method have the potential to be more detailed than comparable visible light microscopes.

While this isn’t quite scanning electron microscope territory, it’s good enough to clearly image the internal workings of a de-capped integrated circuit. Something like this could be indispensable for reverse-engineering ICs or troubleshooting other comparably small electronics, with resolutions higher than can typically be obtained with visible light microscopes. We’ve even seen similar builds in the past which build microscopes like this as dedicated lab equipment.

25 thoughts on “DVD Drives Turned Into Microscopes

    1. The optical pickup unit (OPU) can do not only 3D scan….but 3D printing…
      Micro and nanoscale 3D printing using OPU from a gaming console (https://www.nature.com/articles/s42005-021-00532-4)

      Using DVD OPU for 0.000000001 to 1 Newton force measurement:

      Using DVD OPU for atomic resolution scanning probe microscope

      Hacking CD/DVD/Blu-ray for biosensing

      Here is a video about many OPU applications

    1. I was impressed when I read the small “state of the art section” in the article, that it this project had already been done thrice before with different methods each time

  1. But the CDs exist. Trash thedrives, and they are useless.

    There’s not a lot of CDs I want but don’t have, though sadly prices are rising. I’d rather have my collection than a near infinite streaming collection.

    1. Most writable CDs and DVDs “heal” over time and become unreadable. Libraries found this out early and had programs to duplicate all their media every 5 to 8 years IIRC. We all thought they were going to be a permanent media.

      What is considered the most permanent today? Gold on glass?

      1. M-DISC, if the marketing claims are to be believed. My issue is optical drives are likely not going to be a thing entirely for much longer, and they have a limited life due to diode aging and just general wear. Who really thinks they’re going to be able to buy a DVD drive in 50 years to read their M-DISCs with?

    2. If you look at the link I posted above, CD would be a poor choice IF you were chasing after the ultimate, I was about to say visible wavelength but CD’s use near infrared, maybe single wavelength microscope would be a better choice wording.

      Pit size 800 nm for CD (laser diode wavelength of 780 nm – near infra-red)
      Pit size 400 nm for DVD (laser diode wavelength of 650 nm – red )
      Pit size 150 nm for Blu-ray Disc (laser diode wavelength of 405 nm – technically it is violet, but called Blue for marketing purposes, The Artist Formerly Known as Prince (musician) was still alive at the time and probably would have tried to sued anyone if they called them Purple-ray discs and Violet-ray discs does not really roll off the tongue very well).

      1. The SPOT SIZE is always larger than the pit size, that is why there are large gaps between the tracks. You cannot detect smaller than spot size unless you have dead zones without any information.

  2. You can determine features smaller than the spot size, if you overscan in analogue and apply some Fourier transform math. The magnetic lens alignment/focusing assembly has the potential for high resolution. If you want higher accuracy, perhaps piezoelectric elements could be leveraged, as per the previously HaD featured diy electron microscope.
    I quite like the concept of using the focus to gather depth information from a sample. I wonder if the image sensor from a cheap webcam, with the lens adjusted for microscopy, focusing less than 10mm, have enough resolution to accurately track the reflected light.

  3. [quote]With the advent of streaming services, plenty of people are opting to forego the collection of physical media.[/quote] For me (and probably a few others), I’ve ripped all the DVDs and CDs that I have that I want to keep, so it is all spinning (well spinning being a colloquial term now, as the server media is SSDs). So in that sense you are right, the physical media is not used to often anymore… use once or twice and then sit a shelf forever.

    Neat hack. Problem is I don’t have any I could sacrifice…, all my older optical drives have all been deep-sixed. I have one DVD/CD (almost new in box) as a backup. One true external Blu-Ray/DVD/CD drive in case I need it. All the others are installed in PCs (and rarely used anymore). Not going to chop them up anytime soon!

  4. This technology allows the laser spot to be accurately aligned with the sample on the order of μm.
    I believe that this technology can be applied to laser fault injection attacks on LSI. By controlling the lighting timing of the laser, it may be possible to “invert only a specific bit of memory at an arbitrary timing”.

  5. Hey. I would like to do this project. But I don’t know much about scripting.
    Could someone put more details on the construction, operation and programming in Analog discovery 2, if possible with a video on youtube.
    Thank you very much!

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