Building Petahertz Logic With Lasers And Graphene

May 17, 2022 by Al Williams 19 Comments

There was a time when we thought a 50 MHz 486 was something to get excited about. In comparison, the computer this post was written on clocks in at about 3.8 GHz, which these days, isn’t an especially fast machine. But researchers at the University of Rochester and the Friedrich-Alexander-Universität Erlangen-Nürnberg want to blow the doors off even the fastest modern CPUs. By using precise lasers and graphene, they are developing logic that can operate at nearly 1 petahertz (that’s 1,000,000 GHz).

These logic gates use a pair of very short-burst lasers to excite electrical current in graphene and gold junctions. Illuminating the junctions very briefly creates charge carriers formed by electrons excited by the laser. These carriers continue to move after the laser pulse is gone. However, there are also virtual charge carriers that appear during the pulse and then disappear after. Together, these carriers induce a current in the graphene. More importantly, altering the laser allows you to control the direction and relative composition of the carriers. That is, they can create a current of one type or the other or a combination of both.

This is the key to creating logic gates. By controlling the real and virtual currents they can be made to add together or cancel each other out. You can imagine that two inputs that cancel each other out would be a sort of NAND gate. Signals that add could be an OR or AND gate depending on the output threshold.

[Ignacio Franco], the lead researcher, started working on this problem in 2007 when he started thinking about generating electrical currents with lasers. It would be 2013 before experiments bore out his plan and now it appears that the technique can be used to make super fast logic gates.

We often pretend our logic circuits don’t have any propagation delays even though they do. If you could measure it in femtoseconds, maybe that’s finally practical. Then again, sometimes delays are useful. You have to wonder how much the scope will cost that can work on this stuff.

Lasers Make PCBs The Old Fashioned Way

December 10, 2021 by Al Williams 46 Comments

There are many ways to create printed circuit boards, but one of the more traditional ways involves using boards coated with photoresist and exposing the desired artwork on the board, usually with UV light. Then you develop the board like a photograph and etch it in acid. Where the photoresist stays, you’ll wind up with copper traces. Hackers have used lots of methods to get that artwork ranging from pen plotters to laser printers, but commercially a machine called a photoplotter created the artwork using a light and a piece of film. [JGJMatt] sort of rediscovered this idea by realizing that a cheap laser engraver could directly draw on the photoresist.

The laser dot is about 0.2 mm in diameter, so fine resolution boards are possible. If you have a laser cutter or engraver already, you have just about everything you need. If not, the lower-power laser modules are very affordable and you can mount one on a 3D printer. Most people are interested in using these to cut where higher power is a must, but for exposing photosensitive film, you don’t need much power. The 500 mW module used in the project costs about fifty bucks.

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Microwave Ovens: Need More Power? Use Lasers Instead!

September 28, 2021 by Dave Rowntree 15 Comments

You know how it is, you get in late from work, you’ve been stuck in traffic for what seems like an eternity, and you’re hungry. You reach for the microwave meal, and think, if only I didn’t have to wait that three-and-a-half minutes, 900 watts just isn’t enough power. What you need is a laser microwave, and as luck would have it, [Styropyro] has built one, so you don’t have to. No, really, don’t.

After he observed a microwave only operating on a half-wave basis, and delivering power 50% of the time, he attempted to convert it to full-wave by doubling up the high voltage transformer and rectification diodes. While this worked, the poor suffering magnetron didn’t go the full mile, and died somewhat prematurely.

Not to be disheartened, the obvious thing was to ditch the whole concept of cooking with boring old radio waves, and just use a pile of frickin’ lasers instead. Now we’re not sure how he manages to get hold of some of the parts he uses, and the laser array modules look sketchy to say the least, and to be frank, we don’t think they should be easy to get given the ridiculous beam power they can muster.

With the build completed to the usual [Styropryo] level of excellent build quality, he goes on to produce some mouthwatering delicacies such as laser-charred poptart, incinerated steak with not-really-caramelised onions and our favourite laser-popcorn. OK, he admits the beam has way too much power, really should be infrared, and way more diffuse to be even vaguely practical, but we don’t care about practicality round these parts. Who wouldn’t want the excitement of going instantly blind by merely walking into the kitchen at the wrong time?

We’ve covered a fair few microwave oven related hacks before, including a neat microwave kiln, and hacks using microwave parts, such as a janky Jacob’s ladder, but this is probably the first laser microwave we’ve come across. Hopefully the last :)

And remember kids, as [Styropyro] says in pretty much every video on his channel:

All the crazy stuff I’m about to do was done for educational purposes, in fact if you were to try any of this stuff at home, you’d probably die…

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Harp Uses Frikin’ Lasers

September 14, 2021 by Al Williams 12 Comments

We aren’t sure if you really need lasers to build [HoPE’s] laser harp. It is little more than some photocells and has an Arduino generate tones based on the signals. Still, you need to excite the photocells somehow, and lasers are cheap enough these days.

Mechanically, the device is a pretty large wooden structure. There are six lasers aligned to six light sensors. Each sensor is read by an analog input pin on an Arduino armed with a music-generation shield. We’ve seen plenty of these in the past, but the simplicity of this one is engaging.

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Interactive Musical Art Installation Mixes Vintage, Modern, Lasers, And…Bubbles? Bubbles.

August 21, 2021 by Ryan Flowers 3 Comments

Acorn BBC Master. Apple IIe. Ampex 270 Terminal. Vectrex game console. You’d be hard pressed to find a more diverse hardware collection in the average hacker’s lab. When you add seven Raspberry Pi’s, five CRT monitors, an analog oscilloscope and an LED wall to the mix, one starts to wonder at the menagerie of current and retro hardware. What kind of connoisseur would have such a miscellaneous collection? That’s when you spot smoke and fog machines sitting next to an RGB Laser.

Finally, you learn that all of this disparate paraphernalia is networked together. It is then that you realize that you’re not just dealing with a multi-talented hacker- you’re dealing with a meticulous maestro who’s spent lockdown finishing a project he started nearly twenty years ago!

AUVERN comes alive in a show of light and sound whenever someone enters its view.

The machine is called AUVERN and it’s the product of the creative mind of [Owen]. Taking advantage of advances in technology (and copious amounts of free time), [Owen] laboriously put his collection of older rigs to work.

A Python script uses a Kinect sensor’s input to control a Mac Mini running Digital Audio Workstation software. The operator’s location, poses and movements are used to alter the music, lights, and multimedia experience as a whole. MIDI, Ethernet, and serial communications tie the hardware together through Raspberry Pi’s, vintage MIDI interfaces, and more. Watch the video below the break for the technical explanation, but don’t miss the videos on [Owen]’s website for a mesmerizing demonstration of AUVERN in full swing.

AUVERN makes use of the Vectrex32 upgrade which we have previously covered, and we are unavoidably reminded of another pandemic inspired bubble machine. Don’t forget to send us your hacks, projects, and creations through the Tip Line!

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Thor does battle with a man shooting lasers from his hands

Of Lasers And Lightning: Thwarting Thor With Technology

August 17, 2021 by Adam Zeloof 45 Comments

Most of us don’t spend that much time thinking about lightning. Every now and then we hear some miraculous news story about the man who just survived his fourth lightning strike, but aside from that lightning probably doesn’t play that large a role in your day-to-day life. Unless, that is, you work in aerospace, radio, or a surprisingly long list of other industries that have to deal with its devastating effects.

Humans have been trying to protect things from lightning since the mid-1700s, when Ben Franklin conducted his fabled kite experiment. He created the first lightning rod, an iron pole with a brass tip. He had speculated that the conductor would draw the charge out of thunderclouds, and he was correct. Since then, there haven’t exactly been leaps and bounds in the field of lightning rod design. They are still, essentially, a metal rods that attract lightning strikes and shunt the energy safely into the earth. Just as Ben Franklin first did in the 1700s, they are still installed on buildings today to protect from lightning and do a fine job of it. While this works great for most structures, like your house for example, there are certain situations where a tall metal pole just won’t cut it.

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Hackaday Podcast 124: Hard Drivin’ With Graphene, Fooled By Lasers, Etching With Poison Acid, And All The Linux Commands

June 25, 2021 by Dan Maloney 4 Comments

Hackaday editors Elliot Williams and Mike Szczys marvel at the dangerous projects on display this week, including glass etching with hydrofluoric acid and pumping 200,000 A into a 5,000 A fuse. A new board that turns the Raspberry Pi into an SDR shows off the power of the secondary memory interface (SMI) present in those Broadcom chips. We also discuss the potential for graphene in hard drives, and finish up with a teardown of a very early electronic metronome.

You know you want to read the show notes!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (55 MB or so.)