LED wavelengths

Here you can discuss different microscopic techniques and illumination methods, such as Brightfield, Darkfield, Phase Contrast, DIC, Oblique illumination, etc.
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MichaelG.
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LED wavelengths

#1 Post by MichaelG. » Wed Feb 08, 2023 5:39 am

Technology evolves, of course … but here is a useful primer: https://www.photonics.com/Articles/Ligh ... mer/a36706

The paragraph about Green LEDs is particularly interesting in light of [sorry for the inevitable pun] the current discussion about imaging bacteria.

MichaelG.

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Edit: __ another useful list here: https://www.cresttech.com.au/led_info_wavelength.html
… less technical, but it includes descriptive names for various wavelengths
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Hobbyst46
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Re: LED wavelengths

#2 Post by Hobbyst46 » Wed Feb 08, 2023 10:46 pm

Thanks MichaelG !

Scarodactyl
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Re: LED wavelengths

#3 Post by Scarodactyl » Thu Feb 09, 2023 12:11 am

I don't think that summary is fully accurate--my understanding anyway is that the green gap reflects a legitimate technical challenge rather than a lack of interest.

Hobbyst46
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Re: LED wavelengths

#4 Post by Hobbyst46 » Thu Feb 09, 2023 9:40 am

Citation from https://www.photonics.com/Articles/Ligh ... mer/a36706:

(1)

"Pulsing LEDs in high-current and/or high-voltage mode for arrays in a series-parallel configuration creates a unique set of problems. For the novice designer, it is not practical to design a current-controlled pulse drive with the capability to deliver 5 A and 20 V. There are a few manufacturers of specialty equipment for pulsing LEDs."

Why so ? would that be true for, say, 2A at 12V, which would be fine for microscopy ?

(2)
Just typed "550nm LED" and found Lumixtar.com who offer 540nm, 550nm LEDs, so the "green gap" is not entirely flat...?

MichaelG.
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Re: LED wavelengths

#5 Post by MichaelG. » Thu Feb 09, 2023 1:30 pm

Scarodactyl wrote:
Thu Feb 09, 2023 12:11 am
I don't think that summary is fully accurate--my understanding anyway is that the green gap reflects a legitimate technical challenge rather than a lack of interest.
I think their point was that technical challenges would be addressed if there was sufficient market interest.

It’s a matter of how you prioritise available effort.

MichaelG.
Too many 'projects'

MichaelG.
Posts: 3976
Joined: Mon Apr 10, 2017 8:24 am
Location: North Wales

Re: LED wavelengths

#6 Post by MichaelG. » Thu Feb 09, 2023 1:36 pm

MichaelG. wrote:
Wed Feb 08, 2023 5:39 am
Technology evolves, of course … but
Just as a reminder of my opening line ^^^

I would be very happy to see this thread kept up to date regarding ‘state of the art’

MichaelG.

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P.S.__ I didn’t notice a first publication date for the piece originally linked, it may already be years out of date.
Too many 'projects'

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