TNP #24 - Melles-Griot Triple-Channel Piezoelectric Controller Teardown & Experiments

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  • Опубліковано 4 лис 2024

КОМЕНТАРІ • 64

  • @electronash
    @electronash Рік тому +21

    They used one of these exact units at my old job at Nortel (1999-2001).
    A guy sat at the rig for months, writing some code to try to automate the alignment process for fibre devices.
    It was using a *very* similar X/Y/Z stage to the one shown in the video, but it was probably also Melles-Griot, since the whole optical benches were.
    This was in the "passives" dept., where we built multiplexers and demultiplexers, by manually twiddling knobs on microadjuster stages, to align the fibres and tiny dichroic filter blocks.
    Each fibre was pre-terminated into a SELFOC (Self-Focussing Lens). You would grab the cylindrical lens using the grippers, align the whole thing to the cylindrical lens already on the device, back off the grip a bit, then rotate the fibre gently to align the flat front edge of the cylinder with the lens already in the device (the front edge of the SELFOC was cut at a very slight angle, I would guess for Brewster's angle reasons).
    Then you would move the fibre out again, add a tiny blob of epoxy, then use a dentist-style UV lamp thing to cure the epoxy, 4 minutes total.
    The filter blocks were only about 5mm tall, 5mm wide, and 2mm deep.
    You would use tiny grippers on microadjusters to grab the blocks, align them using laser sources and an OSA (Optical Spectrum Analyzer).
    Once the block was aligned (square-looking waveform from the broad-spectrum laser was centered on the OSA), you would raise it up, use a dentist pick to add epoxy to the bottom of the block, then lower it back down onto the device bed, and UV cure it.
    I think the guy using the Melles-Griot thing was working on active devices, though. I can't quite remember now, but maybe a MEMS VOA thing? He won some kind of award at the end of it.
    We also did some fibre splicing after that, before the whole place got shut down, and much of production moved to Shenzhen, or I think more stuff was made at the HQ in Ottawa instead?
    It was a huge shame, as it was the largest employer here, it paid quite well (for the area), and thousands of people lost their jobs. We had the offer of moving to China to continue working, but very few people took the offer.
    Anyway, that might be very mildly interesting to at least one person here. lol

    • @vincei4252
      @vincei4252 Рік тому +1

      My best friend worked for Nortel for many years in the Maidenhead UK office, I also lived about 300 yards from its front entrance for a couple years. I guess the then CEO buying a plethora of corporate jets for his personal use and other dalliance's eventually sunk the company.

    • @electronash
      @electronash Рік тому

      @@vincei4252 I worked in similar companies for a short time after that, with many ex-Nortel staff.
      The management was pretty bad in most of them. lol
      Even the fact that the main managers rarely used to walk the factory floor with us "plebs" was astounding to me.
      Whenever they were told any major issues, they often ignorred them, yet still wanted to get products tested and shipped to a deadline when it mattered to them.
      I guess a lot of places are like that, but it's a constant surprise to me how often the higher-ups in these places are willing to shoot themselves in the foot.

    • @electronash
      @electronash Рік тому

      Having said that, Nortel was a good place to work overall. I was only there for just under two years, when it all started collapsing (at this specific factory in the South West, you probably know the one I mean).
      For months towards the end (when I finally took "voluntary" redundancy), all the staff were told to try to look like they were doing something when the occasional visitors came by, even though the managers were obviously aware that we had no product to build.
      For the last few months, we would all just sit and chat about movies or going out for a curry. lol
      Almost the entire old site got demolished after. The newer building (Nortel House) is now the college, with other buildings and retail places built around it.
      At one point, there were rumours of Microsoft taking over the old site, but that ofc never happened. I wouldn't have minded working for them.

    • @Thesignalpath
      @Thesignalpath  Рік тому +4

      Thanks, this is great. :)

    • @electronash
      @electronash Рік тому

      @@Thesignalpath This got me looking for photos of inside any generic CWDM device, but it's surprisingly hard to find any.
      I found the old term "GRIN" lens, though. Those were the cylindrical lenses on the ends of the fibres.
      (graded-index rod lens)
      The fibres also had a brass ferule a bit futher down, which poked out a bit from the device itself.
      An engineer at Nortel (Donaldson?) holds the patent for the "solder spigot", which are just pressed toroidal-shaped solder that you reflow with an iron, and it soldered the brass ferule of the fibre onto the device.
      Some of the devices had a second set of tiny dichroic filter blocks placed behind the main ones.
      That would help correct the shape of the waveform on the OSA. I think those filters must have had a generic broadband AR coating on? They made the waveform more "square".
      The main filters reflected the beam in a zig-zag pattern. So the device had about four fibres on one side, and three on the other, with one common input (or output) fibre.
      This is bringing back a lot of memories. A few bad, mostly good. lol

  • @thesoundofphysics
    @thesoundofphysics Рік тому +8

    Would love to see a piezoelectric video! In particular, I'd like to learn more about their use as sensors. Thank you for sharing your knowledge!

  • @coldfinger459sub0
    @coldfinger459sub0 Рік тому +16

    You always get to play with the coolest toys and explain procedures in measuring devices I’ve never even heard of.

  • @AlexTaradov
    @AlexTaradov Рік тому +8

    Many years ago it was a somewhat popular project to do a DIY scanning tunneling microscope with piezo buzzer discs used for stage movement. Some only used one with the ceramic part scribed in 4 quarters.

  • @strange67x
    @strange67x Рік тому +1

    Thanks for the video ! ..... I like your Lab-Cat 🙂

  • @JonaJona
    @JonaJona Рік тому +6

    Finally a topic I feel at least somewhat comfortable with! Piezoactuators are awesome. With piezoelectric stacks as used in this stage you can move huge loads with incredible precision and super high bandwidth (think move as fast as the speed of sound in the material permits) and when you put them in slip-stick stages you can trade the high force for a movement along a long rail pretty much as precise as the roughness of your guide rail allows (like, single nm), while basically only having one moving part (the sled that you're moving, obviously).
    Piezostacks are also pretty efficient in that you can put in and take out energy with very little losses (given you don't use a linear amplifier like this one), so with the right amplifier you can sink 10s of kilowatts of power into them without much heating.
    Also, another vote here that the theme of this channel together with piezoelectrics really calls for an interferometer to be set up!

    • @namibjDerEchte
      @namibjDerEchte Рік тому

      Sounds like a case for a phase modulation setup demonstration.

  • @christophscholz
    @christophscholz Рік тому

    These look exactly like the stages I used for many years in grad school. Aligning tapers fibers to an SOA. These stages made life so much easier. Before I used manual aluminum stages. They had a large hysteresis and drifted with temperature.
    If I remember correctly Melles-Griot also built 6-axis stages and matching controller box that could fine tune the point of maximum coupling.

  • @seeigecannon
    @seeigecannon Рік тому +9

    At my previous job I used to make ultrasonic sensors used for tracking level in sewers (so it was all ATEX rated). The short range sensors would have a crystal about the size of 3 quarters stacked on each other. The long range crystals was about the size of a Red Bull can cut in half. There were several steps where we would need to put the drivers in the oven for epoxy, and you had better have the crystals shorted out otherwise you will get a nice shock when you touch it, and you would never want to feel the long-range discharge a second time. The kicker though is if someone gets shocked when pulling it out of the oven they would think it's safe, but after it cools down it can shock you again because it rebuilt all of that stress.

  • @fredflickinger643
    @fredflickinger643 Рік тому +1

    Very cool! I've always seen these piezo setups in labs but never thought of the driving equipment. Would love to see a whole video on the piezoelectric effect!

  • @grhinson
    @grhinson Рік тому +1

    Weird synchronicity...I have been watching crystal videos all day; then Shahriar posts this video...nice...

  • @MrFaaaaaaaaaaaaaaaaa
    @MrFaaaaaaaaaaaaaaaaa Рік тому +1

    your cat is adorable. I love how they instantly turn their head when they realize you're gonna scratch their itchy head :D lol they love you!!

  • @McTroyd
    @McTroyd Рік тому +2

    Would love to see a piezoelectric video with your usual breakdown!

  • @trevorvanbremen4718
    @trevorvanbremen4718 Рік тому +1

    Looks like you just got yourself a VERY fine microscope stage adjustment device! (Useful when you're at 20 gazillion times magnification)

  • @lasersbee
    @lasersbee Рік тому +1

    Nice review...
    The first time I heard the name Melles Griot was back in 1986 when I bought a used 5mW Gas tube Laser.

  • @WhySoSerious11311
    @WhySoSerious11311 Рік тому +6

    For the X&Y measurement, look for a cheep Brown and Sharpe electronic indicator for sale; they measure down to 0.25 micron. Id also love to see a video with acousto-optics. RF & piezo electrics = best of both worlds.

  • @lmamakos
    @lmamakos Рік тому

    Pooch the lab assistant! Probably he's directing the other videos where he's not making an appearance on camera. Really enjoyed this kind of video in a unique way, where I discover a whole other specialized field of work that I'd not previously been exposed to with any level of detail. Of course there would be instruments to do extraordinarily fine mechanical adjustments! And know I know what they look like.

  • @Heffen89
    @Heffen89 Рік тому +1

    In superconducting accelerators, the cavities are also tuned with piezo crystals in addition to the corase method using motors and gears. This fast piezo tuning helps to compensate for Lorenz force detuning and many other effects inside RF systems.

    • @Thesignalpath
      @Thesignalpath  Рік тому

      That is pretty neat. I have seen MEMs used in similar situations with even finer movement and miniaturized structures.

  • @k5tor185
    @k5tor185 Рік тому +3

    The first and far most important feature is “It does not explode”😂

  • @tommihommi1
    @tommihommi1 Рік тому

    the new picoscope software seems like a game changer, and it seems pooch is interested in that as well :D
    Had a chat with one of their engineers a few days ago and they seemed really proud of it.

  • @adamsiwek7995
    @adamsiwek7995 Рік тому +2

    I would like to see more of that.

  • @DasIllu
    @DasIllu Рік тому +2

    Bought an oscilloscope, bought a bench multimeter, bought tons of soldering gear.... yet still something is missing.
    I need a lab kitty! 😀

  • @Ziferten
    @Ziferten Рік тому +1

    Submitting my request for a dedicated video about Pooch.

  • @dharmadove
    @dharmadove Рік тому +1

    Cool!

  • @MattyEngland
    @MattyEngland Рік тому +5

    The piezoelectric controller is cool, but your cat is way cooler 😂👍

  • @dktr2
    @dktr2 Рік тому +1

    Piezo is also used in some hard drives for precise head positioning.

    • @Thesignalpath
      @Thesignalpath  Рік тому +1

      Yes! At the highest storage density the fine adjustment of the head is done with piezo elements. It is incredible how they do it.

  • @hydrogenger9364
    @hydrogenger9364 Рік тому

    Yes,
    Would appreciate more videos of this instrument with Piezo 3-axis stages,
    with measurements in the Photonics realm.
    Suggestions:
    Scanning & data collection with fiber lasers, fiber detectors, FO spectrophotometers;
    Or FO SA's, or perhaps programmed automated CCD pixel scanning, etc.. ??
    Or characterization and repeatability of the Piezo stages themselves.
    Or photonic experiment measurement set-ups.
    Yes: would like to see your repair of the 3-axis Piezo stage !
    There was an MG attachment that provided higher resolution movement (sub micron ?),
    I believe it was a Capacitive measurement feedback device ?
    Tons of these ( orig. List price of ~20k+ ?) were liquidated by Nortel for ~$100@ back in 2002, during the bankruptcy. Many went to China in bulk sales. Major job losses, pension and stock, all evaporated.

  • @guillep2k
    @guillep2k Рік тому +1

    I don't know what's the bandwidth of that device, but I expected you to use a mirror, a laser, and plot some signal on the wall or something. 😀

  • @PushyPawn
    @PushyPawn Рік тому +4

    I would love to know how it looks inside.

  • @megabytephreak
    @megabytephreak Рік тому

    Neat.I'd like to see a TNP on that (LVDT?) linear transducer setup.

    • @andrewnambudripad762
      @andrewnambudripad762 Рік тому +1

      Yeap good guess. That LVDT is jacked into a Fowler D100. Pretty standard (and decently priced on the used market) gear that uses RS232. If you want to see some more exotic metrology gear in the machine shop, YTer Hyugen's Optics featured some real interesting gear (the "Spherometer" line from TRIoptics in Gehhrmany, so it has to be good) to quantify the eccentricity of lenses.

  • @byronwatkins2565
    @byronwatkins2565 Рік тому

    You also could buy ONE stage and replace the PZT elements.

  • @The_Paya
    @The_Paya Рік тому +1

    Brain works in the frequency domain, try to say "from 0 to 75" but "from DC to 75" comes out 🙃

  • @gacherumburu9958
    @gacherumburu9958 Рік тому

    👍👍

  • @PlasmaHH
    @PlasmaHH Рік тому

    Often you use these actuators not necessarily for their fine adjustments but for the vibration free adjustment capabilities.

  • @AndrewZonenberg
    @AndrewZonenberg Рік тому +3

    Was hoping you'd demo it with a Michelson interferometer. Came here for pretty interference fringes and left disappointed.
    More content on piezos and optics would be cool though.

    • @Thesignalpath
      @Thesignalpath  Рік тому +1

      That was actually on my list as something to try. But I didn't have enough time to set it up. I need mirrors, splitters, lenses, etc.

  • @NeuroMod
    @NeuroMod Рік тому +1

    I would like to see underwater acoustic modem teardown and experiments. These are also based on piezos

    • @MrFaaaaaaaaaaaaaaaaa
      @MrFaaaaaaaaaaaaaaaaa Рік тому +3

      ah yes, the equipment that costs *ask for quote*
      lol :D

    • @SeanBZA
      @SeanBZA Рік тому

      @@MrFaaaaaaaaaaaaaaaaa And also comes with ITAR paperwork you have to fill out, before you can even get the sales people to give you the paperwork to request the quote.

  • @universeisundernoobligatio3283

    Use lots of piezoelectric accelerometers for gas turbine R&D, always thought they were dynamic devices that did not respond to DC, learned something new here.
    Is it certain types of crystal or will any piezoelectric device change their static shape with DC voltage?

    • @Thesignalpath
      @Thesignalpath  Рік тому

      They react to charge injection into the crystal structures, as a result they would also respond to DC. They also store charge and can have capacitive properties.

  • @Debraj1978
    @Debraj1978 Рік тому

    From your experiment, this transducer appear to be linear. And bandwidth is not important for the intended application (align fiber optics).
    But can this transducer be used for application which needs fast changes (example laser light show to move a mirror to draw images on smoke)?

    • @Thesignalpath
      @Thesignalpath  Рік тому

      I did not measure the BW in this case, it is something I'd like to try. But as with most mechanical things, the entire system size & weight impacts the BW too. Piezo can be made extremely fast when they are slow. The smaller you make them, less total displacement you will get of course.

    • @JonaJona
      @JonaJona Рік тому +1

      The bandwidth of piezoelectrics depends almost entirely on the mechanical properties of your setup, i.e. the piezo can move your mirror as fast as the speed of sound within the piezo and mirror permits. This is true to the degree where the deceleration of the mirror can be so rapid that it rips the rather brittle piezo material apart if you don't account for it with some counteracting force that pushes the piezo together. There's some nice guides by PI ceramics if you're interested in the characteristics of dynamic piezo operation.
      I think measuring the bandwidth of the piezos in the video will likely fail on two accounts: 1) The whole system will just shake uncontrollably in all directions, long before the dimensions of the actual piezo elements go noticeably out of sync with the drive voltage since this stage setup is likely not optimized for stiffness. 2) Since this looks to be a linear amplifier it obviously has to ultimately dissipate all of the energy going through it as heat. As you said in the video, even for a linear amplifier this appears to really not be a particularly high power unit. Considering the energy stored in every acceleration cycle needs to be completely dissipated during deceleration I doubt that amplifier will run these piezos at resonance frequency for very long (if even for a single ramp).

  • @thomasw6169
    @thomasw6169 Рік тому

    Let's build a AFM/ SPM.

  • @GJackie24
    @GJackie24 Рік тому +1

    Is that kitties real name "Pooch" or does you beautiful fur baby have another name ?

  • @johnshaw359
    @johnshaw359 Рік тому

    You are splitting hairs now.

  • @glasslinger
    @glasslinger Рік тому

    Sometimes I wonder if some of the fantastic equipment you come up with is stolen. Seems like the junk price of the item would be a lot more than what you claim to have paid. Find some instrument in a dumpster and maybe it was there because the pawn shop would not give anything for it.

  • @ravishkasilva2851
    @ravishkasilva2851 Рік тому

    diesel injectors

  • @reedpetersen
    @reedpetersen Рік тому +1

    First