strange blue laser optics

[John Larkin]

I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

I got a mild headache from just looking at the spot on the wall for
under a minute total. I also get a mild headache from using a UV
flashlight.


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Lasse Langwadt Christense]

fredag den 13. marts 2020 kl. 00.02.22 UTC+1 skrev John Larkin:

I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

I got a mild headache from just looking at the spot on the wall for
under a minute total. I also get a mild headache from using a UV
flashlight.

https://youtu.be/-2crWR1lg6s

 

[John Larkin]

On Thu, 12 Mar 2020 16:25:21 -0700 (PDT), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

fredag den 13. marts 2020 kl. 00.02.22 UTC+1 skrev John Larkin:
I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

I got a mild headache from just looking at the spot on the wall for
under a minute total. I also get a mild headache from using a UV
flashlight.


https://youtu.be/-2crWR1lg6s

My eye doctor, a really cool guy, blasted my right eye with his old CW
argon ion laser, to spot-weld my retina to the back of my eyeball.
That kinda hurt. He's Thai and his first and last names are both about
20 characters long, so everybody calls him Dr B. My retina was mostly
detatched and getting worse, so he came in at 10 PM and fixed it.

He also removed a secondary cataract by cutting a hole in the rear of
my lens capsule with a pulsed yag.

The blue "burning" laser makes a very hot spot if you focus it
carefully.



--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[John Robertson]

On 2020/03/12 4:02 p.m., John Larkin wrote:

I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

I got a mild headache from just looking at the spot on the wall for
under a minute total. I also get a mild headache from using a UV
flashlight.

I 'like' the description "High quality and perfect design." where have
we heard 'perfect' before? And why should you trust them?

I'm very suspicious of any and all unregulated products from China. They
claim it is 405nm, but unless you have a spectrum analyzer you have no
idea if it is also emitting UV-B or other dangerous UV radiation.
Perhaps you could lend one to Winfield - I imagine he has one of those
S.A.s rattling around his shop!

Wear proper UV safety glasses (at a minimum UV-A/B rated sun glasses)
when using this.

https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/uv-protection/faq-20058021

I'd treat it like light from an arc-welder, dangerous until proven
otherwise.

John :-#(#

 

John Robertson <spam@flippers.com> wrote in
news:mcudnQEjsuRaVvfDnZ2dnUU7-X3NnZ2d@giganews.com:

I 'like' the description "High quality and perfect design." where
have we heard 'perfect' before? And why should you trust them?

Because they are such 'great businessmen'.

Finished at the top of their class...

All work is performed by stable geniuses.
But all the facts about how they operate are 'classified'.

 

[John Larkin]

On Thu, 12 Mar 2020 16:54:46 -0700, John Robertson <spam@flippers.com>
wrote:

On 2020/03/12 4:02 p.m., John Larkin wrote:


I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

I got a mild headache from just looking at the spot on the wall for
under a minute total. I also get a mild headache from using a UV
flashlight.



I 'like' the description "High quality and perfect design." where have
we heard 'perfect' before? And why should you trust them?

I'm very suspicious of any and all unregulated products from China. They
claim it is 405nm, but unless you have a spectrum analyzer you have no
idea if it is also emitting UV-B or other dangerous UV radiation.
Perhaps you could lend one to Winfield - I imagine he has one of those
S.A.s rattling around his shop!

Wear proper UV safety glasses (at a minimum UV-A/B rated sun glasses)
when using this.

https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/uv-protection/faq-20058021

I'd treat it like light from an arc-welder, dangerous until proven
otherwise.

Well, toothpicks are dangerous too, if you poke one in your eye.

John :-#(#

It seems to work. The spot, well focussed, feels very hot on my hand,
so it's a lot of power. It came with a spot-matrix-pattern diffuser
installed, which might be prudent to leave in place for curing epoxy.
Amazing for under $10.

I wish I had a wideband spectrum analyzer, ideally something like 350
to 1700 nm. All the available OSAs go for extreme resolution over a
narrow range, well under an octave. I just want to know about what the
wavelength of a laser or LED is.

--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Rick C]

On Thursday, March 12, 2020 at 8:59:37 PM UTC-4, John Larkin wrote:

I wish I had a wideband spectrum analyzer, ideally something like 350
to 1700 nm. All the available OSAs go for extreme resolution over a
narrow range, well under an octave. I just want to know about what the
wavelength of a laser or LED is.

If you only want an approximate number you can get that by comparing the color by eye. Look at the laser spot on white paper, look at a known LED on the same white paper. You should be able to get within a few 10s of nm. The eye is very sensitive to pure colors.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[David Nadlinger]

On 13.03.20 12:59 am, John Larkin wrote:

All the available OSAs go for extreme resolution over a
narrow range, well under an octave. I just want to know about what the
wavelength of a laser or LED is.

Available as in available at your shop? Otherwise, there are quite a few
good (but $$$) options, e.g.
https://www.highfinesse.com/en/spectrometer-osa/laser-spectrum-analyzer.html.

— David

 

[Robert Baer]

John Larkin wrote:

On Thu, 12 Mar 2020 16:54:46 -0700, John Robertson <spam@flippers.com
wrote:

On 2020/03/12 4:02 p.m., John Larkin wrote:


I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

I got a mild headache from just looking at the spot on the wall for
under a minute total. I also get a mild headache from using a UV
flashlight.



I 'like' the description "High quality and perfect design." where have
we heard 'perfect' before? And why should you trust them?

I'm very suspicious of any and all unregulated products from China. They
claim it is 405nm, but unless you have a spectrum analyzer you have no
idea if it is also emitting UV-B or other dangerous UV radiation.
Perhaps you could lend one to Winfield - I imagine he has one of those
S.A.s rattling around his shop!

Wear proper UV safety glasses (at a minimum UV-A/B rated sun glasses)
when using this.

https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/uv-protection/faq-20058021

I'd treat it like light from an arc-welder, dangerous until proven
otherwise.

Well, toothpicks are dangerous too, if you poke one in your eye.


John :-#(#


It seems to work. The spot, well focussed, feels very hot on my hand,
so it's a lot of power. It came with a spot-matrix-pattern diffuser
installed, which might be prudent to leave in place for curing epoxy.
Amazing for under $10.

I wish I had a wideband spectrum analyzer, ideally something like 350
to 1700 nm. All the available OSAs go for extreme resolution over a
narrow range, well under an octave. I just want to know about what the
wavelength of a laser or LED is.

A CD or DVD disk does not help?

 

[Jasen Betts]

On 2020-03-12, John Larkin <jlarkin@highland_atwork_technology.com> wrote:

I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

Some artificial lenses are transparnt to UV, your original lens is not.

I got a mild headache from just looking at the spot on the wall for
under a minute total.

Possilby your visual cortex stressed by the significantly different
inputs.

--
Jasen.

 

[Phil Hobbs]

On 2020-03-12 19:02, John Larkin wrote:

I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

There was a Car Talk puzzler many years ago that hinged on that--optical
signalling to the French resistance using UV filters that made the
flashes visible to old men (who had had cataracts removed) but not to
young German soldiers.

I got a mild headache from just looking at the spot on the wall for
under a minute total. I also get a mild headache from using a UV
flashlight.

UV epoxy is usually designed for Hg I-line (365-nm) peak sensitivity. I
generally use a 380-nm LED, which works fine. How well does your 405 work?

CHeers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Phil Hobbs]

On 2020-03-12 20:59, John Larkin wrote:

On Thu, 12 Mar 2020 16:54:46 -0700, John Robertson <spam@flippers.com
wrote:

On 2020/03/12 4:02 p.m., John Larkin wrote:


I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

I got a mild headache from just looking at the spot on the wall for
under a minute total. I also get a mild headache from using a UV
flashlight.



I 'like' the description "High quality and perfect design." where have
we heard 'perfect' before? And why should you trust them?

I'm very suspicious of any and all unregulated products from China. They
claim it is 405nm, but unless you have a spectrum analyzer you have no
idea if it is also emitting UV-B or other dangerous UV radiation.
Perhaps you could lend one to Winfield - I imagine he has one of those
S.A.s rattling around his shop!

Wear proper UV safety glasses (at a minimum UV-A/B rated sun glasses)
when using this.

https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/uv-protection/faq-20058021

I'd treat it like light from an arc-welder, dangerous until proven
otherwise.

Well, toothpicks are dangerous too, if you poke one in your eye.


John :-#(#


It seems to work. The spot, well focussed, feels very hot on my hand,
so it's a lot of power. It came with a spot-matrix-pattern diffuser
installed, which might be prudent to leave in place for curing epoxy.
Amazing for under $10.

I wish I had a wideband spectrum analyzer, ideally something like 350
to 1700 nm. All the available OSAs go for extreme resolution over a
narrow range, well under an octave. I just want to know about what the
wavelength of a laser or LED is.

You can do that with a CD and a ruler, with an IR viewer for the longer
wavelengths. (I have a somewhat-broken lead salt vidicon camera that
used to go out to 2.2 um.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[TTman]

On 13/03/2020 02:28, Rick C wrote:

On Thursday, March 12, 2020 at 8:59:37 PM UTC-4, John Larkin wrote:

I wish I had a wideband spectrum analyzer, ideally something like 350
to 1700 nm. All the available OSAs go for extreme resolution over a
narrow range, well under an octave. I just want to know about what the
wavelength of a laser or LED is.

If you only want an approximate number you can get that by comparing the color by eye. Look at the laser spot on white paper, look at a known LED on the same white paper. You should be able to get within a few 10s of nm. The eye is very sensitive to pure colors.

Unless you're colour blind..... Not so easy !

 

[Phil Hobbs]

On 2020-03-13 06:42, TTman wrote:

On 13/03/2020 02:28, Rick C wrote:
On Thursday, March 12, 2020 at 8:59:37 PM UTC-4, John Larkin wrote:

I wish I had a wideband spectrum analyzer, ideally something like 350
to 1700 nm. All the available OSAs go for extreme resolution over a
narrow range, well under an octave. I just want to know about what the
wavelength of a laser or LED is.

If you only want an approximate number you can get that by comparing
the color by eye.  Look at the laser spot on white paper, look at a
known LED on the same white paper.  You should be able to get within a
few 10s of nm.  The eye is very sensitive to pure colors.

Unless you're colour blind..... Not so easy !

And even with normal vision, that kind of resolution is only available
between 450 and 600 nm at best.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

On Fri, 13 Mar 2020 05:37:25 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-03-12 20:59, John Larkin wrote:
On Thu, 12 Mar 2020 16:54:46 -0700, John Robertson <spam@flippers.com
wrote:

On 2020/03/12 4:02 p.m., John Larkin wrote:


I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

I got a mild headache from just looking at the spot on the wall for
under a minute total. I also get a mild headache from using a UV
flashlight.



I 'like' the description "High quality and perfect design." where have
we heard 'perfect' before? And why should you trust them?

I'm very suspicious of any and all unregulated products from China. They
claim it is 405nm, but unless you have a spectrum analyzer you have no
idea if it is also emitting UV-B or other dangerous UV radiation.
Perhaps you could lend one to Winfield - I imagine he has one of those
S.A.s rattling around his shop!

Wear proper UV safety glasses (at a minimum UV-A/B rated sun glasses)
when using this.

https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/uv-protection/faq-20058021

I'd treat it like light from an arc-welder, dangerous until proven
otherwise.

Well, toothpicks are dangerous too, if you poke one in your eye.


John :-#(#


It seems to work. The spot, well focussed, feels very hot on my hand,
so it's a lot of power. It came with a spot-matrix-pattern diffuser
installed, which might be prudent to leave in place for curing epoxy.
Amazing for under $10.

I wish I had a wideband spectrum analyzer, ideally something like 350
to 1700 nm. All the available OSAs go for extreme resolution over a
narrow range, well under an octave. I just want to know about what the
wavelength of a laser or LED is.


You can do that with a CD and a ruler, with an IR viewer for the longer
wavelengths. (I have a somewhat-broken lead salt vidicon camera that
used to go out to 2.2 um.)

Cheers

Phil Hobbs

So it wouldn't be difficult to design a small wide-range, low
resolution spectrometer, with some cheap gratings, an IR sensitive
webcam, and a little software.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

On Fri, 13 Mar 2020 10:42:34 +0000, TTman <kraken.sankey@gmail.com>
wrote:

On 13/03/2020 02:28, Rick C wrote:
On Thursday, March 12, 2020 at 8:59:37 PM UTC-4, John Larkin wrote:

I wish I had a wideband spectrum analyzer, ideally something like 350
to 1700 nm. All the available OSAs go for extreme resolution over a
narrow range, well under an octave. I just want to know about what the
wavelength of a laser or LED is.

If you only want an approximate number you can get that by comparing the color by eye. Look at the laser spot on white paper, look at a known LED on the same white paper. You should be able to get within a few 10s of nm. The eye is very sensitive to pure colors.

Unless you're colour blind..... Not so easy !

Or unless you are wondering if a laser is 850, 1310, or 1550 nm.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

On Fri, 13 Mar 2020 05:34:49 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-03-12 19:02, John Larkin wrote:


I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

There was a Car Talk puzzler many years ago that hinged on that--optical
signalling to the French resistance using UV filters that made the
flashes visible to old men (who had had cataracts removed) but not to
young German soldiers.


I got a mild headache from just looking at the spot on the wall for
under a minute total. I also get a mild headache from using a UV
flashlight.

UV epoxy is usually designed for Hg I-line (365-nm) peak sensitivity. I
generally use a 380-nm LED, which works fine. How well does your 405 work?

CHeers

Phil Hobbs

Bondic comes with a fairly wimpy blue LED, and it sets the stuff up
hard in seconds. Clear through vias to the bottom of the board.

I haven't tried my super laser on Bondic. I'll do that today.



--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

On Fri, 13 Mar 2020 15:20:12 +0000, Jeff Layman
<jmlayman@invalid.invalid> wrote:

On 12/03/20 23:47, John Larkin wrote:

The blue "burning" laser makes a very hot spot if you focus it
carefully.

Sure does at 450nm!
https://www.gearbest.com/laser-engraver---cnc/pp_009352360226.html?wid=1433363

We are buying a bunch of custom machined extrusions from China, as
small instrument boxes. We will locally blue anodize them and their
custom end plates, to keep the colors uniform. Then we plan to add the
artwork by blasting off the anodize with a CO2 laser.

https://www.dropbox.com/s/7yuarcttj4tv49b/J734_Blue_Box.JPG?raw=1

I think the n/c laser will cost around $3K or so.





--

John Larkin Highland Technology, Inc

The cork popped merrily, and Lord Peter rose to his feet.
"Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"

 

[Jeff Layman]

On 12/03/20 23:47, John Larkin wrote:

The blue "burning" laser makes a very hot spot if you focus it
carefully.

Sure does at 450nm!
<https://www.gearbest.com/laser-engraver---cnc/pp_009352360226.html?wid=1433363>

--

Jeff

 

[Phil Hobbs]

On 2020-03-13 10:37, jlarkin@highlandsniptechnology.com wrote:

On Fri, 13 Mar 2020 05:37:25 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-03-12 20:59, John Larkin wrote:
On Thu, 12 Mar 2020 16:54:46 -0700, John Robertson <spam@flippers.com
wrote:

On 2020/03/12 4:02 p.m., John Larkin wrote:


I got a couple of these, to maybe cure UV-set epoxy.

https://www.ebay.com/itm/High-Power-Purple-405nm-Pointer-Burning-Light-Beam-Pen-with-Battery-Charger-USA/383162483108?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

It came with a big lithium battery and a charger.

Two weird things:

If I shoot it at a white wall, I can see the spot with my right eye,
but not with my left one. The right eye has had cataract lens
replacement.

I got a mild headache from just looking at the spot on the wall for
under a minute total. I also get a mild headache from using a UV
flashlight.



I 'like' the description "High quality and perfect design." where have
we heard 'perfect' before? And why should you trust them?

I'm very suspicious of any and all unregulated products from China. They
claim it is 405nm, but unless you have a spectrum analyzer you have no
idea if it is also emitting UV-B or other dangerous UV radiation.
Perhaps you could lend one to Winfield - I imagine he has one of those
S.A.s rattling around his shop!

Wear proper UV safety glasses (at a minimum UV-A/B rated sun glasses)
when using this.

https://www.mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/uv-protection/faq-20058021

I'd treat it like light from an arc-welder, dangerous until proven
otherwise.

Well, toothpicks are dangerous too, if you poke one in your eye.


John :-#(#


It seems to work. The spot, well focussed, feels very hot on my hand,
so it's a lot of power. It came with a spot-matrix-pattern diffuser
installed, which might be prudent to leave in place for curing epoxy.
Amazing for under $10.

I wish I had a wideband spectrum analyzer, ideally something like 350
to 1700 nm. All the available OSAs go for extreme resolution over a
narrow range, well under an octave. I just want to know about what the
wavelength of a laser or LED is.


You can do that with a CD and a ruler, with an IR viewer for the longer
wavelengths. (I have a somewhat-broken lead salt vidicon camera that
used to go out to 2.2 um.)

Cheers

Phil Hobbs


So it wouldn't be difficult to design a small wide-range, low
resolution spectrometer, with some cheap gratings, an IR sensitive
webcam, and a little software.

Right, provided you always start with a collimated beam. "IR-sensitive
webcam" is the hard part. An Electrophysics 7290A from eBay and a USB
frame grabber would be the ticket for that.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net