You just drill the size hole they spec & the press-fit in. Works with both aluminum & plastic enclosures: image782×258 69.2 KB

Also, if you have three LEDs in a row like that, you might want to consider a single piece light pipe that has three channels. It’s more likely that the leakage was taken into consideration, and it might make assembly easier.

Incoherent sources are the exact opposite of coherent sources. These types of sources emit light with frequency, and there are random changes in phase between the photons.

Quantum coherence

Coherence is also the property which enables waves to have stationary interference. Besides, the amount of coherence is usually measured by interference visibility. For instance, two parallel slits lighted by a laser beam can be classified as two coherent point sources. We will learn about this concept in detail, along with types, characteristics, coherent sources and more here.

We need coherent sources of light mainly to observe the effects of interference. Coherent sources have the same phase, so the phase difference between the two sources remains constant. This is a necessary condition for observable and distinct interference.  They help us identify the interference patterns that occur as a result of the change in phase at a given point (at source, at the screen ). This also gives us the minima and maxima, i.e. constructive and destructive interference, which can be seen at different points on the screen simultaneously.

coherence中文

Additionally, the property of coherence is the basis for many other applications. Some of the popular ones are as follows:

Another car was a Cadillac that a friend borrowed from a family member for a week or two. Along the roof line on the driver’s side, just above the windshield, was a row of what looked like LED indicators. But they were not LEDs, of course. They were light pipes which snaked through the car to each of the four corners and monitored the parking, hazard, brake, turn signals, and reverse lights. If you had a blown bulb, you’d know it before being pulled over by a policeman.

I remember back in college in the early 1980s, I encountered light “pipes” twice – both times in cars. The first was my old Datsun B210, and a couple of the dashboard switches were illuminated by a light pipe. The light bulb for the indicator was deeper inside the dash somewhere, and it was routed to the switch in some kind of fiber pipe. This was like a 1976 car, so I don’t think it was using fiber optics as we know it today.

Order today, ships today. VLP-500-F – Light Pipe Single Clear Rigid Board Mount, Press Fit from Bivar Inc.. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

Coherent sources of light are those sources which emit a light wave having the same frequency, wavelength and in the same phase, or they have a constant phase difference. A coherent source forms sustained interference patterns when the superimposition of waves occurs, and the positions of maxima and minima are fixed.

For what its worth, I used the Dialight 51513020125F (datasheet) on Joulescope. It’s good enough. For one LED, its relatively easy. Drill a hole the right size and try different light pipes to get the right look. As @coflynn says, you do have to worry about light leakage with multiple LEDs.

Opposite to holography, the superposition of non-optical wavefields is also considered. For example, in quantum mechanics, there is a consideration for the probability field, which is related to the wave function. The applications of coherent waves can be seen among the future technologies of field quantum computing, etc.

I used this to bring an onboard LED on a dev board out of a 3D printed enclosure and was very happy with the result. Assembly was a pain. Regardless, it’s a great prototyping option.

Radiography is an old technique. Very recently, it took a new way that the coherence of a next-generation facility beam makes it possible in an easy way to break the usual barrier to absorption and to visualise phase features. The X-ray beam has,

Examples of incoherent sources include all conventional light sources. The transitions between energy levels in an atom are a completely random process. So, we have no control over when an atom is going to lose energy in the form of radiation.

Holography makes use of coherent superpositions of optical wave fields, and its uses are commonly found in credit cards.

Incoherentlight

Hey @Dave, welcome! New members are restricted from posting images and links immediately, as a spam prevention technique. A bit annoying, but you should be able to post those things after a bit of browsing/reading other threads. We hope you stick around!

Finding a coherent source of light is sometimes difficult. Therefore, we can use different methods to produce such sources, and they are as follows:

What ismonochromaticlight

I got scared off by the official parts but just using diagonal cutters on 1/8" acrylic rod worked well enough for the T2 tiles.

Coherence describes the properties of the interrelation between physical quantities of a single wave or between several waves. Two waves are coherent when they have a constant relative phase or when they have zero or constant phase difference and the same frequency.

What I can say is that, you’re right, they are a bit of an art to design right. Don’t underestimate the leakage between the light pipes, and double/triple check your order of operations for assembly.

Interference is a phenomenon in which two waves superimpose to form a resultant wave which has greater, lower or the same amplitude. Interference is of types – constructive and destructive. They result from the combination of waves that are interrelated or coherent with each other, either because they come from the same source or because they have the same or nearly the same frequency.

“Clear” resin prints from 3D printers can be good enough, at least for prototype. Disney was already working on that a decade ago Disney Research develops 3D printed optics

Has anyone had any experience with using light pipes to pipe out LED light from the LEDs on your PCB to the exterior of your enclosure? From what I understand, it is kind of an art. Any tips?

(Aaand I can’t post images… Aand I can’t post links. Well I tried. There’s a picture at/movablefeastmachine.com/t2-tile-pipe-cu.jpg )

Coherentwave

Coherent lightsource examples

Temporal coherence is a measure of the average relationship between the value of a wave and itself, making a delay of τ at any considerable pair of times.

I’ve used the ones from Bivar and will be using this one specifically on my next project: Link But they have a large number of them, including right angle ones. I mention it since this one mounts over the LED and has pins to keep it in place, some form of glue will be needed to keep it in place most likely. This might be easier for aligning the light pipe to the LED, but then you need to worry about the pipe’s location in relation to the enclosure.

We can take a reference of Newton’s ring phenomenon or make use of Michelson’s interferometer arrangement or configuration.

I’ve only used light pipes one time (and am planning on using them a second time soon) and the kind I used was pretty simple. It worked well for what I wanted it to do which was bring light above some potting that was put over the entire board.

Like any spec part like this, you’ll end up needing to design mechanical elements around the part, which carries inherent risks in the supply chain (whaaaat? In 2021??). However, having it in the design with a custom footprint fit the “just works” criteria that is always satisfying in a project. The link above is for a vertical part, so it won’t fit your project, but there might be similar parts available.

Sometimes the phases interfere at such a high rate that our eyes are not able to detect the simultaneous formation of fringes.

If your main goal is to get distinct channels of light out to the enclosure exterior, but you are not super picky, then any piece of plastic would do much better than not having the light pipe. The key thing to remember is the critical angle of the light reflecting in the material – you want to maximize the internal reflections in the plastic to get the light that you shoot into the entry aperture to go out the exit aperture. By managing that carefully, you can make single piece light pipes with multiple light channels and can combine variety of shapes/placements/sizes AND also have features that make it easy to mount the light pipe into your design (whether on the PCB or on the enclosure).

These characteristics of the beam, which are due to its super brilliance, allow new techniques to be developed in the X-ray field:

I’ve use the PLP2 series (which looks like the original photo). They always feel expensive, but my usage it’s normally not totally killer.

For the ones you listed in the picture, they are press fit. That kit looks like it comes with a good variety of lengths and the three different heads on the pipe. Looks like there should be some that fit what you are looking for though.

(Aaand I can’t post images… Aand I can’t post links. Well I tried. There’s a picture at/movablefeastmachine.com/t2-tile-pipe-cu.jpg )

The only real caveat with them is to watch for leakage/misalignment. If you pack them closely together & use LEDs with a wide field of view angles, the light will leak into adjacent pipes. Ideally get LEDs with vary narrow field of view. You also want the end of the pipe to be as close as possible to the LED surface. You never get “right there” so I normally end up with 1-3mm space (3mm is probably a little too much). You can swap the LEDs for ones with a lens on them to close up the gap if needed.

Coherent lightmeaning

Depending upon how picky you are, light pipe design can be complicated. You can end up with “hot-spots”. Creating even light from all angles across the whole light pipe surface often requires more diffusion or bouncing the light. From past product experience with the Hillcrest Loop where the acrylic part had to light up just right, getting the exact illumination and diffusion requires design and experimentation. We had a great MechE do a bunch of experiments.

Various Accessories such as screwable and snap-in fastening flanges, as well as different coding pens in various colors are available

A coherent source can be created by taking the incoming beam and dividing its amplitude into different parts through a process of partial reflection or refraction. Later, these parts that travel through new paths meet with each other creating an interference.

Wavefront is divided into several parts. We can use either different lenses, mirrors, and even prisms. Some of the techniques that can be followed are Young’s double-slit experiment, Lloyd’s mirror arrangement, Fresnel’s biprism method, etc.

Two independent sources are never coherent, or they cannot be considered coherent sources, as all the above-mentioned factors cannot be present at the same time.

Coherent lightsource meaning

I’ve had some experience with light pipes a long time ago (and I won’t bother repeating what many other people have already said).

If you’re not too careful on the hole size or worried about them popping out, you can put a bit of epoxy on the backside with a syringe. We do that anyway as I’m always worried they will somehow, I think it’s pretty unlikely in practice.

You need the right material for light conduction - acrylic is generally used, I think - and highly polished outer surfaces for maximum internal reflection. I’ve had decent prototype results with urethane casting done by a professional model shop.

When a wave has a single amplitude value over an infinite length, it is said to have perfect spatial coherence. The significant interference that is present between the range of separation and the two points can be used to define the diameter of the coherence area, Ac.