Found this twitter post of interesting purple LED street-lights.

From what I understand, these are violet-diode LEDs with RGB type phosphors. The pumping of the phosphor(s) having failed, the violet diode is seen only for the street-light.

Can someone find more info and if possible post a link to the typical spectral output of these violet-phosphor LED systems?

Long article: https://www.manufacturer.lighting/info/223/

I'm starting to find some links regarding their spectral output:

https://www.chameleonforums.com/threads/a-really-neat-new-led.173498/
https://www.soraa.com/learn/science/tm-30-trade-offs.php

It is indeed a technique to get that better spectrum, but it will have two drawbacks:
- It emits quite significant amount of the high energy "violet" (technically long wave UVA), which could become a problem for compatibility with some materials used for lantern optics (unlike other "white" light sources, "classic" white LED does not radiate anything with energy beyond the primary blue peak, some material compositions used for LED lanterns may count on that)
- Any conversion means losses, so this concept won't have that high efficacy as the "classic".

So in a perfect world with honest marketing, these could be very valuable complement to the more "traditional" LEDs, taking over the applications where the higher color quality is of more importance than the disadvantages and the "traditional" ones will be used with more standard  applications where the efficacy (that means not only energy consumption, but mainly the heat management complexity and cost) plays more important role.

But I'm afraid it will fall victim of the many political and mythological pressures so at the end it will either be stomped into ground or used where it is not optimal, so cause more harm than good.

From the few articles and spectral diagrams I've seen thus far, (attached), an insignificant amount of UVA is radiated by these violet-LED systems. Of course this is probably an idealized depiction.

Since the lighting industry believes that consumers want very high color rendering properties (for certain applications), then wouldn't these violet LEDs find their way in areas such as the garment industry or for  store displays rather quickly?

But I'm afraid it will fall victim of the many political and mythological pressures so at the end it will either be stomped into ground or used where it is not optimal, so cause more harm than good.

That is not new, and that's why the LED and CFL "boom" came into the market, by 3rd's pressure, forcing those products in the consumers.

From the few articles and spectral diagrams I've seen thus far, (attached), an insignificant amount of UVA is radiated by these violet-LED systems. Of course this is probably an idealized depiction.

Since the lighting industry believes that consumers want very high color rendering properties (for certain applications), then wouldn't these violet LEDs find their way in areas such as the garment industry or for  store displays rather quickly?

The depiction looks real. Of course the UV is by far not dominant in the total radiated power, bu even quite small intensity could do a lot of harm over the time.

That is not new, and that's why the LED and CFL "boom" came into the market, by 3rd's pressure, forcing those products in the consumers.

The "3'rd party force" just speed up the process a bit.
But yes, it is exactly this "force", what at the end becomes responsible for the "bad name" the LEDs have these days. Because it created the room on the market for the very low quality products that are plaquing many installations these days.
But even without the artificial push, the incandescents would be nearly an extinct specie anyway.

The "3'rd party force" just speed up the process a bit.
But yes, it is exactly this "force", what at the end becomes responsible for the "bad name" the LEDs have these days. Because it created the room on the market for the very low quality products that are plaquing many installations these days.
But even without the artificial push, the incandescents would be nearly an extinct specie anyway.

Without the "pressure", there would be a pleny light variety, each light technology with their application, e.g. carbon lamps as decoration, with the "pressure" we would have LED lights inside ovens and microwaves, and LED infarred heaters, instead of carbon fiber ones. All that is kind of happening.

Why would any utility install these as street-lights???

News item about the violet issue.

Why would any utility install these as street-lights???

News item about the violet issue.

That link doesn't work here.

Here's the story without all the FoxNews frames and adverts:

Seeing purple street lights? Duke Energy wants you to let them know

    Dal Kalsi
    Updated Mar 16, 2021 | Posted on Mar 16, 2021

Image:Purple Street Light

An example of a purple street light found in the Upstate. This one is on Stone Avenue near I-385.
(Source: FOX Carolina)

GREENVILLE, SC (FOX Carolina) - Duke Energy said some of the new LED street lights they have installed over the past few years have begun to glow purple, and the utility provider is asking people who encounter any purple lights to report them. A spokesman for the company said hundreds of these lights may need to be replaced across the Upstate.

"We have been upgrading many of our older, less efficient lights with LED lighting over the last few years, and plan to continue this transition in the years ahead," explained Duke Energy spokesman Ryan Mosier. "While the vast majority of our LED lighting performs very well in communities across the state, we have identified a small pocket of LED lights in our service that have turned from the standard white color to a deep purple color."

Mosier said the change in color is from a manufacturer defect that has only been recently identified and one that Duke is working with the manufacturer to remedy. Aside from the gradual color change, Mosier said the lights otherwise work fine.

"We have been replacing or repairing these lights as they are identified, and we have alerted our field crews to look for and report any of these lights that they encounter," Mosier said.

The company also asks customers to be on the lookout and report any purple lights they encounter as well. Once reported, the defective lights should be repaired within a few days. The good news is the lights are still under warranty, so the cost to repair these lights will not be absorbed by Duke customers.

There are two ways you can report a purple light:

    Request a street light repair: www.duke-energy.com/customer-service/request-light-repair
    Call customer service: 800.777.9898

"We believe this issue is isolated to one manufacturing batch of LED lights. Other utilities across the nation using the same stock of lights are experiencing similar issues. We are working with the vendor to better understand the issue and they are taking steps to ensure it does not happen again," Mosier concluded.

Who made these “PurpLED” fixtures? 

My mom would love to have purple LED lights as area lighting for the house. Purple is her favorite color.