Good video. Slight correction though: Both portions of the diode, n and p are essentially neutral in charge. However in the n-type portions the CHARGE CARRIERS are negative (electrons), as is the case in a metallic conductor; and in the p-type portion the CHARGE CARRIERS (holes) are positive. At the junction, in the depletion region, electrons cross over from the n-type portion to fill the holes of the p-type region (or, if you please, the holes cross from the p-type to be filled by electrons in the n-type, the two statements are equivalent), so that in the depletion region (very close on each side of the junction) there is a net negative charge in the p-type and a net positive charge in the n-type.
Was going to say this too, thanks for correction. Its worth noting that although there is more electrons or holes in the conduction bands, for every DONATED or ACCEPTED charge carrier a positive or negative ion is created respectively, effectively neutralizing the material.
Yup the lasing portion is essentially a very heavily doped region with the lesser doped regions supplying the charge injection into the lasing region. I used to bake laser diodes at a company called Boston Lasers using a MOCVD machine that would build them layer by layer on 2 inch wafers of gallium arsenide. For visible ones they used aluminum to replace gallium to make the wavelength shorter. One day we were making 633nm wafers and the injection valve gave 2 extra shots of trimethyl aluminum and we rolled with it. We ended up making bright orange laser diodes of 604nm that made about 250mw at 1.2A and 15 degC temperature. Seeing that much pure orange light from a laser diodr was very cool.❤
Small correction: lenses are not how lasers make different shapes. Lenses focus (converge) or defocus (diverge) a beam. Diffraction gratings and/or holograms are used to make the beam into a pretty picture.
Duck Hunt for Nintendo doesn't use a laser to hit the screen. When the trigger is pulled the screen flashes. If the controller is pointed at the correct spot the sensor picks up on the dot that is flashed on the screen over where the target was. This is picked up by the controller and registers a hit or a miss depending. Just so you know
hi, thanks for the explanation, but light does not come in parallel and collimated straight from the diode, rather it can be collimated with a lens if the source is point (single-mode, with waveguide width less then the wavelength)
I remember my first laser diode came out of a xerox docutech printer. It was a barely visible red light that came from a optical assembly with a few lenses in it. Eventually that got used with a real red laser diode of 635nm...fast forward to 2023. You now have cheap blue GaN lasers that can burn holes in stuff that can be powered by a single lithium battery.😮 The most interesting ones are the green output ones at about 515nm that can be used to replace big bulky argon lasers for many applications.❤
Haven't mentioned my favorite type VCSEL (Vertical-cavity surface-emitting laser), This is a much more advanced alternative to PIN diodes, it is really powerful and quite cheap for near infrared.
She is confusing the two types. Look at how she shows the cavity with the light bouncing, and the direction of the collimated beam perpendicular to it. That makes zero sense.
Yup those are very interesting because the active layer is so thin they can be modulated extremely quickly. The power was low for a very long time until a company called Novalux found an ingenious way to stack the quantum wells to make much higher powers. Next they packaged them with KTP or KNbO3 crystals and made extremely efficient lasers operating at visible wavelength. Then the blue and green nitride lasers ate their lunch.😂
I wanna make a bet that the next generation of parents won’t name their daughters Karen, pretty sad as a name alone doesn’t automatically determine the character of a person but people just assume
A housing where the ceiling of each room has an optical fiber lighting array running across it; which is then covered with a coat of diffuser material. Then connect each array to a central light generating unit that sends light through the array when a light switch is turned on. Instead of lightbulbs, lamps, and copper wiring, the ceiling of the room would emit its own light
I use 450 mn laser for engrave/print a lot of things, actualy with FAC tecnology and double beam can easy cut plywood. But the big problem is how extract heat from the module 'cos the fan isn't enought. Any suggestion?
Hi Tnx for your learning video. in the video you mentioned a laser safety graph, i would like to know more about it and its reference so i can use it at my university lab. I'll be grateful for your help...
wow this is the first time i see this beautiful video of laser and i love laser and this love starter when i was 22 years old now im 58 years old and how this love for laser starter back in 1984 i went to a beautiful Pink Floyd concert in Oakland coliseum and they have all thos laser and i belived is the first band or show using this ligths in all world
Sorry to ask you something different: My project consist of a blanket with température sensor, heartbeat sensor and alarm to avoid death by malaria. Sometimes babies die in bed by malaria, temperature rises nobody will notice. Which sensor to use? In blanket, on socks or in mattress?
thank you very much. now I know how they work, but can anyone explain how they are made ( manufacturing process) ? I dont get how they make the mirrors in between the junctions, I cant find a satisfactory explanation.
I'm skeptical that the animation is accurate. For example, how does the light turn almost 90 degrees to escape the intrinsic layer? I believe the mirrors might be the edges of the intrinsic layer that are not attached to the semiconductors. But i could be wrong
Hello Karen, Thank you so much and the team for those contents. Enabling so many educational path for younger tinkerer. Sometimes i believe, because of the opensource thoughts in the community, we build a future of small heroes, who are building the gears for medicin, bakers, schools or science. Electric Engineering is a major to understand more deeply our creational cause rather intriguied conspiracy ideologies. In the head is not in the hand, and nature is providing us with so much variety of projects. For Example freaking lasers!! Projects for people, Projects with people or Projects be creative! :) Have a wonderful and healthy Christmas! Thank you element14! Best Greetings from Germany Viet
If it is a "diode laser" for hair removal, then yes. (Basically, the principles are the same, the way they are manufactured could be one of several sub-types) The manufacturer of your consumer device will not be specific.
Most laser printers now use LEDs, not lasers. They used to use lasers, but advancements in LED manufacture allowed cheaper LED arrays to perform the same task. By that point though, the name had stuck - laser printers had come to be seen as an indicator of of quality and reliability, so no manufacturer would want to brand their printers as not-laser. They just carried on calling them laser printers even after the laser was removed.
@@suhailab3634 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-_saDCwsB9Ww.html en.wikipedia.org/wiki/LED_printer If you look around, I'm sure you can still find a real laser printer - but I work in IT support, and I've taken a lot of 'laser' printers apart. HPs mostly, an occasional Brother, some big Sharp multi-function units, and one Kyocera. I've yet to come across an actual laser in any of them. The industry moved to LED printing years ago because the quality is just as good, it's more reliable and costs less. They just kept on saying laser, because consumers associate laser with high-tech and LED with budget.
Thank you for the video is the biggest difference between laser diode and an LED that it has a polished mirroring layer? and what would this be made of in material perspective??
Not necessarily polished (the process) but highly reflective and flat. Reflectivity on one side as close to 100% as one an get, on the opposite side about 95+% so that some of the beam can escape. The multiple reflections between the "mirror" surfaces is what creates the Amplification (the A in LASER). Note that her drawing in the beginning of the video is incorrect.
Yes they did that with Coherent's optically pumped semiconductor lasers such as the 488nm Sapphire system. In that a 800nm laser diode optically pumps a semiconductor laser that lases at 976nm and that is doubled to 488nm using a lithium borate crystal.❤
Those shapes are created by a grating, only after being fully collimated by a lens. Also, the light waves which escape don't act the way you showed them to behave, a very small portion of the photons which are alignted to exactly 90 degrees with the mirror facets, front and back (one mirror perhaps only reflecting 90%) will escape as collimated light.
There is a new generation of blue laser diodes with a downconverting phosphor layer operating similar to white LEDs. They offer a considerably higher luminance, although a collimated beam is transformed to a uniform Lambetian one by a phosphor
Yup they use 5W blue or UV nitride lasers with a phosphor bonded to a sapphire window to build these laser driven light sources. They are quite popular for automobile headlamps and microscope/endoscope lamps mainly. If I ever get one I'll probably use it for a bright flashlight.❤
YAY...100th comment. Anyway, when heard "phonons" I was like....what? And then read some on wikipedia and now it seems I can simply make up any quantum theory and say it's legit.
Congratulations on not wearing those gloves anymore and moving into a place that looks clean. I am visiting dongguan now, so I wish I could say the view from the window looked that clean.
People should really stop using laser pointers as pet toys, the reflected beam can still cause harm to the eye of the animal. Even if it's not immediate obvious that a surface can reflect the laser, it often can reflect enough to be harmfull. Also many laser pointers, especially the cheaper ones, outputs way more light than they advertise, especially in the infrared spectrum which despite being invissible, are still harmfull to the eye.
So many mistakes and corners being cut while explaining how it works. For instance, what exactly makes emission to be parallel ? You didn't explain that
I am afraid you are confusing edge emitters with surface emitters. Nobody believes the laser cavity is created by reflections between the boundary of the N-type material and the lasing medium on one side and the boundary of the P-type meterial and the lasing medium on the other side... and mysteriously the light is semi-collimated in the direction perpendicular to these surfaces.
how about wall indirect light with rgb+white 256 colors? for tv room, for bar, for boAT AND ARIPLANUS ,,, dang myu disluxya is flayrn up , cyall laturs!
Ho fatto una stupida scoperta nel 1977 da bambino 12 enne, da un semplice (chiodo) OA85 un diodo a baffo di gatto al (anodo) tungsteno e germanio saldato sul reoforo con lo stagno che è il catodo, che alimentandolo a 9V inversamente si è illuminato come una lampadina da 75 W, tutto racchiuso da un cilindro in vetro, al confronto dei LED del 1962 si mostravano pallidi fatti con silicio drogato con arsenico e gallio e contatti e substratto in argento o oro e ora in alluminio che fa da specchio e la capsula fa da lente plastica anti riciclo, la cosa divertente :( e che nel 2010 gli scienziati scoprano il silicio e germanio drogati di stagno si illumina meglio e si fanno pure i migliori LASER a diodi a semiconduttori e si abbattono pure costi e inquinamento, fatta presente questa bella notizia del 1977 ben 44 anni dopo, non sanno che rispondere se hai la laurea al Faggin o al Oliver Twist.
Just one thing if you are going to be working with these devices then please wear a welding helmet with the visor down if you value your eyes and your friends don't point the device at them also.
