Trying to Find Class 1 Laser Diode

[Patty]

I need to make a laser pointer for a profoundly disabled friend. It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements. Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

Thanks.

Trish

 

[krw@att.bizzzzzzzzzzzz]

On Thu, 23 Jun 2011 15:51:12 -0700 (PDT), Patty <bonnypatty@gmail.com> wrote:

I need to make a laser pointer for a profoundly disabled friend. It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements. Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

What color?

 

[George Herold]

On Jun 23, 6:51 pm, Patty <bonnypa...@gmail.com> wrote:

I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

Thanks.

Trish

How about a filter over the end of more common laser pointer to reduce
the power?

I'm trying to think of good 'easy' filter. If you only need a few I
can put a 'piece of plastic' in the mail. You'll have to cut and tape
pieces over the end of the ~5 mW laser.

George H.

 

[Patty]

On Jun 23, 8:17 pm, "k...@att.bizzzzzzzzzzzz"
<k...@att.bizzzzzzzzzzzz> wrote:

On Thu, 23 Jun 2011 15:51:12 -0700 (PDT), Patty <bonnypa...@gmail.com> wrote:
I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

What color?

Thanks a lot for your response. Color isn't so important as long as
his pointer would still be easily visible when it hits an object
(plastic communication board because my fiend is aphasic) about 3
inches away.

Trish

 

[Patty]

On Jun 23, 7:17 pm, George Herold <gher...@teachspin.com> wrote:

On Jun 23, 6:51 pm, Patty <bonnypa...@gmail.com> wrote:

I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

Thanks.

Trish

How about a filter over the end of more common laser pointer to reduce
the power?

I'm trying to think of good 'easy' filter.  If you only need a few I
can put a 'piece of plastic' in the mail.  You'll have to cut and tape
pieces over the end of the ~5 mW laser.

George H.

Thanks so much, George! I'll reply separately.

Trish

 

On Thu, 23 Jun 2011 21:48:49 -0700 (PDT), Patty <bonnypatty@gmail.com>
wrote:

On Jun 23, 8:17 pm, "k...@att.bizzzzzzzzzzzz"
k...@att.bizzzzzzzzzzzz> wrote:
On Thu, 23 Jun 2011 15:51:12 -0700 (PDT), Patty <bonnypa...@gmail.com> wrote:
I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

What color?

Thanks a lot for your response. Color isn't so important as long as
his pointer would still be easily visible when it hits an object
(plastic communication board because my fiend is aphasic) about 3
inches away.

Trish
At that distance, and depending on ambient lighting, you might find a

"super bright" high efficiency LED that would work,

A small plastic magnifying glass for a focusing lens, PVC pipe to hold
it in alignment ... Add a pushbutton switch .... Projected you get a
picture of the LED die, about a 1mm square with ordinary 5mm type LEDs

A similar technique might work with a laser diode and make it much
safer. Diffuse or spread the beam then sharply focus it at 3".
Further away it would spread enough to be safe (depending on his
ability to keep it on target and how close together the targets are)

 

[George Herold]

On Jun 24, 12:52 am, Patty <bonnypa...@gmail.com> wrote:

On Jun 23, 7:17 pm, George Herold <gher...@teachspin.com> wrote:





On Jun 23, 6:51 pm, Patty <bonnypa...@gmail.com> wrote:

I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

Thanks.

Trish

How about a filter over the end of more common laser pointer to reduce
the power?

I'm trying to think of good 'easy' filter.  If you only need a few I
can put a 'piece of plastic' in the mail.  You'll have to cut and tape
pieces over the end of the ~5 mW laser.

George H.

Thanks so much, George!  I'll reply separately.

Trish- Hide quoted text -

- Show quoted text -

Hi Trish, We sell a bunch of plastic neutral density (ND) filters.
We get big sheets from Tiffin and then chop 'em up... There is always
some edge bits that we can't use and these are just sitting going to
waste on our shelves... These are listed as ND=0.70, the neutral
density is a log of intensity ratio, an ND=1 lets through 10% of the
power, ND 0.7 lets through about 20%. But there's plenty of
variation from piece to piece. I stuck a few pieces in front of a
HeNe laser and had intensity at the output varied from 22% to 15%.

I'm not sure how you are going to measure the intensity of any laser
you might find.
I don't suppose you have a photodiode laying around?

Maybe you can try sticking one or two together and see how you like
it. I put two in in front of the 0.5mW HeNe and could still easily
see the beam on the wall.

Perhaps the one issue to worry about is too much intensity. At
higher intensities I've 'burnt a hole' in the plastic. Not a real
hole mind you but the gelatin that makes up the ND filter changes
somehow if it gets too hot. I can't give you some hard and fast
number for this intensity as it depends on the spot size of your
laser.


George H.

 

[George Herold]

On Jun 24, 12:48 am, Patty <bonnypa...@gmail.com> wrote:

On Jun 23, 8:17 pm, "k...@att.bizzzzzzzzzzzz"

k...@att.bizzzzzzzzzzzz> wrote:
On Thu, 23 Jun 2011 15:51:12 -0700 (PDT), Patty <bonnypa...@gmail.com> wrote:
I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

What color?

Thanks a lot for your response.  Color isn't so important as long as
his pointer would still be easily visible when it hits an object
(plastic communication board because my fiend is aphasic) about 3
inches away.

Trish

Use a red laser pointer I've heard reports that the cheap green ones
sometimes have some of the NIR laser light at the output.

George H.

 

[krw@att.bizzzzzzzzzzzz]

On Thu, 23 Jun 2011 21:48:49 -0700 (PDT), Patty <bonnypatty@gmail.com> wrote:

On Jun 23, 8:17 pm, "k...@att.bizzzzzzzzzzzz"
k...@att.bizzzzzzzzzzzz> wrote:
On Thu, 23 Jun 2011 15:51:12 -0700 (PDT), Patty <bonnypa...@gmail.com> wrote:
I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

What color?

Thanks a lot for your response. Color isn't so important as long as
his pointer would still be easily visible when it hits an object
(plastic communication board because my fiend is aphasic) about 3
inches away.

You can find the guts of cheap laser pointers with a quick web search. They're
available with <1mW and up. Red lasers, with drive electronics, run about
$5-$20. Greens are larger, more expensive, and a bit harder to come by.
They're probably a lot brighter than you need.

 

[Patty]

I have some misgivings about proceeding with a modified Class 2
laser. Before I'd always read statements like "Eye damage is
impossible with Class 1 lasers even after hours of exposure), due to
their low output power.' Never a statement about power. However,
delving into it further to make sure that the 25% reduction of a Class
2 (< 1mW of power) would be the equivalent or better than a Class 1, I
finally found this on the OSHA web site: "Class I: cannot emit laser
radiation at known hazard levels (typically continuous wave: cw 0.4 ľW
at visible wavelengths). . . ." So I'm now thinking I best try to
make the best of the super bright LEDs, at least 'til I can find a
configuration for the laser pointer that I can determine is, for sure,
safefor my friend.

Thank you again for your kind offer and your help in understanding
this.

Pat



Class I: cannot emit laser radiation at known hazard levels (typically
continuous wave: cw 0.4 ľW at visible wavelengths). Users of Class I
laser products are generally exempt from radiation hazard controls
during operation and maintenance (but not necessarily during service).

On Jun 24, 7:16 am, George Herold <gher...@teachspin.com> wrote:

On Jun 24, 12:52 am, Patty <bonnypa...@gmail.com> wrote:









On Jun 23, 7:17 pm, George Herold <gher...@teachspin.com> wrote:

On Jun 23, 6:51 pm, Patty <bonnypa...@gmail.com> wrote:

I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

Thanks.

Trish

How about a filter over the end of more common laser pointer to reduce
the power?

I'm trying to think of good 'easy' filter.  If you only need a few I
can put a 'piece of plastic' in the mail.  You'll have to cut and tape
pieces over the end of the ~5 mW laser.

George H.

Thanks so much, George!  I'll reply separately.

Trish- Hide quoted text -

- Show quoted text -

Hi Trish,  We sell a bunch of plastic neutral density (ND) filters.
We get big sheets from Tiffin and then chop 'em up... There is always
some edge bits that we can't use and these are just sitting going to
waste on our shelves... These are listed as ND=0.70, the neutral
density is a log of intensity ratio, an ND=1 lets through 10% of the
power,  ND 0.7 lets through about 20%.  But there's plenty of
variation from piece to piece.  I stuck a few pieces in front of a
HeNe laser and had intensity at the output varied from 22% to 15%.

I'm not sure how you are going to measure the intensity of any laser
you might find.
I don't suppose you have a photodiode laying around?

Maybe you can try sticking one or two together and see how you like
it.  I put two in in front of the 0.5mW HeNe and could still easily
see the beam on the wall.

Perhaps the one issue to worry about is too much intensity.   At
higher intensities I've 'burnt a hole' in the plastic.  Not a real
hole mind you but the gelatin that makes up the ND filter changes
somehow if it gets too hot.  I can't give you some hard and fast
number for this intensity as it depends on the spot size of your
laser.

George H.

 

[Patty]

Thanks a lot for the idea about the super bright LED. I have tried
'pretty bright LED flashlights' without much success, but I'll give
your suggestion a go.

Thank you.

Trish

 

[George Herold]

On Jun 24, 4:57 pm, Patty <bonnypa...@gmail.com> wrote:

I have some misgivings about proceeding with a modified Class 2
laser.  Before I'd always read statements like "Eye damage is
impossible with Class 1 lasers even after hours of exposure), due to
their low output power.'  Never a statement about power.  However,
delving into it further to make sure that the 25% reduction of a Class
2 (< 1mW of power) would be the equivalent or better than a Class 1, I
finally found this on the OSHA web site: "Class I: cannot emit laser
radiation at known hazard levels (typically continuous wave: cw 0.4 ľW
at visible wavelengths). . . ."  So I'm now thinking I best try to
make the best of the super bright LEDs, at least 'til I can find a
configuration for the laser pointer that I can determine is, for sure,
safefor my friend.

Thank you again for your kind offer and your help in understanding
this.

Pat

Class I: cannot emit laser radiation at known hazard levels (typically
continuous wave: cw 0.4 ľW at visible wavelengths). Users of Class I
laser products are generally exempt from radiation hazard controls
during operation and maintenance (but not necessarily during service).

On Jun 24, 7:16 am, George Herold <gher...@teachspin.com> wrote:



On Jun 24, 12:52 am, Patty <bonnypa...@gmail.com> wrote:

On Jun 23, 7:17 pm, George Herold <gher...@teachspin.com> wrote:

On Jun 23, 6:51 pm, Patty <bonnypa...@gmail.com> wrote:

I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

Thanks.

Trish

How about a filter over the end of more common laser pointer to reduce
the power?

I'm trying to think of good 'easy' filter.  If you only need a few I
can put a 'piece of plastic' in the mail.  You'll have to cut and tape
pieces over the end of the ~5 mW laser.

George H.

Thanks so much, George!  I'll reply separately.

Trish- Hide quoted text -

- Show quoted text -

Hi Trish,  We sell a bunch of plastic neutral density (ND) filters.
We get big sheets from Tiffin and then chop 'em up... There is always
some edge bits that we can't use and these are just sitting going to
waste on our shelves... These are listed as ND=0.70, the neutral
density is a log of intensity ratio, an ND=1 lets through 10% of the
power,  ND 0.7 lets through about 20%.  But there's plenty of
variation from piece to piece.  I stuck a few pieces in front of a
HeNe laser and had intensity at the output varied from 22% to 15%.

I'm not sure how you are going to measure the intensity of any laser
you might find.
I don't suppose you have a photodiode laying around?

Maybe you can try sticking one or two together and see how you like
it.  I put two in in front of the 0.5mW HeNe and could still easily
see the beam on the wall.

Perhaps the one issue to worry about is too much intensity.   At
higher intensities I've 'burnt a hole' in the plastic.  Not a real
hole mind you but the gelatin that makes up the ND filter changes
somehow if it gets too hot.  I can't give you some hard and fast
number for this intensity as it depends on the spot size of your
laser.

George H.- Hide quoted text -

- Show quoted text -

Yeah, laser's are a bit scary, I wish people would be more careful.

The bit's of plastic are in the mail. If you stack up three of the
filters that will be more than 2.0 ND only 1% of the power will be
coming through. You can try stacking more.

Part of laser saftey is counting on peoples blink reflex. Which is
why green laser diodes that leak some of the NIR fundamental are
scarier. I have no idea if the plastic bits block the 1064 nm light.
See under green here,

http://en.wikipedia.org/wiki/Laser_pointer

George H.

 

[George Herold]

On Jun 24, 4:57 pm, Patty <bonnypa...@gmail.com> wrote:

I have some misgivings about proceeding with a modified Class 2
laser.  Before I'd always read statements like "Eye damage is
impossible with Class 1 lasers even after hours of exposure), due to
their low output power.'  Never a statement about power.  However,
delving into it further to make sure that the 25% reduction of a Class
2 (< 1mW of power) would be the equivalent or better than a Class 1, I
finally found this on the OSHA web site: "Class I: cannot emit laser
radiation at known hazard levels (typically continuous wave: cw 0.4 ľW
at visible wavelengths). . . ."  So I'm now thinking I best try to
make the best of the super bright LEDs, at least 'til I can find a
configuration for the laser pointer that I can determine is, for sure,
safefor my friend.

Thank you again for your kind offer and your help in understanding
this.

Pat

Class I: cannot emit laser radiation at known hazard levels (typically
continuous wave: cw 0.4 ľW at visible wavelengths). Users of Class I
laser products are generally exempt from radiation hazard controls
during operation and maintenance (but not necessarily during service).

<snip bottom stuff... on usenet people like you to bottome post.>

I missed the 0.4uW number. With a 5mW input laser you'd need an ND of
a bit more than 4. that will be six layers of ND=0.7 plastic, you can
at least see if that's enough light.

George H.

 

[Patty]

On Jun 24, 6:16 pm, George Herold <gher...@teachspin.com> wrote:

On Jun 24, 4:57 pm, Patty <bonnypa...@gmail.com> wrote:









I have some misgivings about proceeding with a modified Class 2
laser.  Before I'd always read statements like "Eye damage is
impossible with Class 1 lasers even after hours of exposure), due to
their low output power.'  Never a statement about power.  However,
delving into it further to make sure that the 25% reduction of a Class
2 (< 1mW of power) would be the equivalent or better than a Class 1, I
finally found this on the OSHA web site: "Class I: cannot emit laser
radiation at known hazard levels (typically continuous wave: cw 0.4 ľW
at visible wavelengths). . . ."  So I'm now thinking I best try to
make the best of the super bright LEDs, at least 'til I can find a
configuration for the laser pointer that I can determine is, for sure,
safefor my friend.

Thank you again for your kind offer and your help in understanding
this.

Pat

Class I: cannot emit laser radiation at known hazard levels (typically
continuous wave: cw 0.4 ľW at visible wavelengths). Users of Class I
laser products are generally exempt from radiation hazard controls
during operation and maintenance (but not necessarily during service).

snip bottom stuff... on usenet people like you to bottome post.

I missed the 0.4uW number.  With a 5mW input laser you'd need an ND of
a bit more than 4.  that will be six layers of ND=0.7 plastic, you can
at least see if that's enough light.

George H.

Thanks, George. I'll try it!

Trish

 

[Patty]

On Jun 24, 6:07 pm, George Herold <gher...@teachspin.com> wrote:

On Jun 24, 4:57 pm, Patty <bonnypa...@gmail.com> wrote:









I have some misgivings about proceeding with a modified Class 2
laser.  Before I'd always read statements like "Eye damage is
impossible with Class 1 lasers even after hours of exposure), due to
their low output power.'  Never a statement about power.  However,
delving into it further to make sure that the 25% reduction of a Class
2 (< 1mW of power) would be the equivalent or better than a Class 1, I
finally found this on the OSHA web site: "Class I: cannot emit laser
radiation at known hazard levels (typically continuous wave: cw 0.4 ľW
at visible wavelengths). . . ."  So I'm now thinking I best try to
make the best of the super bright LEDs, at least 'til I can find a
configuration for the laser pointer that I can determine is, for sure,
safefor my friend.

Thank you again for your kind offer and your help in understanding
this.

Pat

Class I: cannot emit laser radiation at known hazard levels (typically
continuous wave: cw 0.4 ľW at visible wavelengths). Users of Class I
laser products are generally exempt from radiation hazard controls
during operation and maintenance (but not necessarily during service).

On Jun 24, 7:16 am, George Herold <gher...@teachspin.com> wrote:

On Jun 24, 12:52 am, Patty <bonnypa...@gmail.com> wrote:

On Jun 23, 7:17 pm, George Herold <gher...@teachspin.com> wrote:

On Jun 23, 6:51 pm, Patty <bonnypa...@gmail.com> wrote:

I need to make a laser pointer for a profoundly disabled friend..  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

Thanks.

Trish

How about a filter over the end of more common laser pointer to reduce
the power?

I'm trying to think of good 'easy' filter.  If you only need a few I
can put a 'piece of plastic' in the mail.  You'll have to cut and tape
pieces over the end of the ~5 mW laser.

George H.

Thanks so much, George!  I'll reply separately.

Trish- Hide quoted text -

- Show quoted text -

Hi Trish,  We sell a bunch of plastic neutral density (ND) filters.
We get big sheets from Tiffin and then chop 'em up... There is always
some edge bits that we can't use and these are just sitting going to
waste on our shelves... These are listed as ND=0.70, the neutral
density is a log of intensity ratio, an ND=1 lets through 10% of the
power,  ND 0.7 lets through about 20%.  But there's plenty of
variation from piece to piece.  I stuck a few pieces in front of a
HeNe laser and had intensity at the output varied from 22% to 15%.

I'm not sure how you are going to measure the intensity of any laser
you might find.
I don't suppose you have a photodiode laying around?

Maybe you can try sticking one or two together and see how you like
it.  I put two in in front of the 0.5mW HeNe and could still easily
see the beam on the wall.

Perhaps the one issue to worry about is too much intensity.   At
higher intensities I've 'burnt a hole' in the plastic.  Not a real
hole mind you but the gelatin that makes up the ND filter changes
somehow if it gets too hot.  I can't give you some hard and fast
number for this intensity as it depends on the spot size of your
laser.

George H.- Hide quoted text -

- Show quoted text -

Yeah, laser's are a bit scary, I wish people would be more careful.

The bit's of plastic are in the mail. If you stack up three of the
filters that will be more than 2.0 ND only 1% of the power will be
coming through.  You can try stacking more.

Part of laser saftey is counting on peoples blink reflex.  Which is
why green laser diodes that leak some of the NIR fundamental are
scarier.  I have no idea if the plastic bits block the 1064 nm light.
See under green here,

http://en.wikipedia.org/wiki/Laser_pointer

George H.

I'll try 6 layers of the plastic with a RED laser.

Thank you, George!

Trish

 

[Patty]

On Jun 24, 6:55 pm, Patty <bonnypa...@gmail.com> wrote:

On Jun 24, 6:07 pm, George Herold <gher...@teachspin.com> wrote:









On Jun 24, 4:57 pm, Patty <bonnypa...@gmail.com> wrote:

I have some misgivings about proceeding with a modified Class 2
laser.  Before I'd always read statements like "Eye damage is
impossible with Class 1 lasers even after hours of exposure), due to
their low output power.'  Never a statement about power.  However,
delving into it further to make sure that the 25% reduction of a Class
2 (< 1mW of power) would be the equivalent or better than a Class 1, I
finally found this on the OSHA web site: "Class I: cannot emit laser
radiation at known hazard levels (typically continuous wave: cw 0.4 ľW
at visible wavelengths). . . ."  So I'm now thinking I best try to
make the best of the super bright LEDs, at least 'til I can find a
configuration for the laser pointer that I can determine is, for sure,
safefor my friend.

Thank you again for your kind offer and your help in understanding
this.

Pat

Class I: cannot emit laser radiation at known hazard levels (typically
continuous wave: cw 0.4 ľW at visible wavelengths). Users of Class I
laser products are generally exempt from radiation hazard controls
during operation and maintenance (but not necessarily during service)..

On Jun 24, 7:16 am, George Herold <gher...@teachspin.com> wrote:

On Jun 24, 12:52 am, Patty <bonnypa...@gmail.com> wrote:

On Jun 23, 7:17 pm, George Herold <gher...@teachspin.com> wrote:

On Jun 23, 6:51 pm, Patty <bonnypa...@gmail.com> wrote:

I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

Thanks.

Trish

How about a filter over the end of more common laser pointer to reduce
the power?

I'm trying to think of good 'easy' filter.  If you only need a few I
can put a 'piece of plastic' in the mail.  You'll have to cut and tape
pieces over the end of the ~5 mW laser.

George H.

Thanks so much, George!  I'll reply separately.

Trish- Hide quoted text -

- Show quoted text -

Hi Trish,  We sell a bunch of plastic neutral density (ND) filters.
We get big sheets from Tiffin and then chop 'em up... There is always
some edge bits that we can't use and these are just sitting going to
waste on our shelves... These are listed as ND=0.70, the neutral
density is a log of intensity ratio, an ND=1 lets through 10% of the
power,  ND 0.7 lets through about 20%.  But there's plenty of
variation from piece to piece.  I stuck a few pieces in front of a
HeNe laser and had intensity at the output varied from 22% to 15%.

I'm not sure how you are going to measure the intensity of any laser
you might find.
I don't suppose you have a photodiode laying around?

Maybe you can try sticking one or two together and see how you like
it.  I put two in in front of the 0.5mW HeNe and could still easily
see the beam on the wall.

Perhaps the one issue to worry about is too much intensity.   At
higher intensities I've 'burnt a hole' in the plastic.  Not a real
hole mind you but the gelatin that makes up the ND filter changes
somehow if it gets too hot.  I can't give you some hard and fast
number for this intensity as it depends on the spot size of your
laser.

George H.- Hide quoted text -

- Show quoted text -

Yeah, laser's are a bit scary, I wish people would be more careful.

The bit's of plastic are in the mail. If you stack up three of the
filters that will be more than 2.0 ND only 1% of the power will be
coming through.  You can try stacking more.

Part of laser saftey is counting on peoples blink reflex.  Which is
why green laser diodes that leak some of the NIR fundamental are
scarier.  I have no idea if the plastic bits block the 1064 nm light.
See under green here,

http://en.wikipedia.org/wiki/Laser_pointer

George H.

I'll try 6 layers of the plastic with a RED laser.

Thank you, George!

Trish

One more little glitch. Now I'm Googling for a Class 2 red pointer.
I find a few, but one of them has this warning (no doubt a translation
from Chinese): "The laser can bright enough when you light it in
normal temperature, so you had better do not light it continually in
30 seconds". Will 'constant-on' be a problem. My friend (who's a
quadriplegic) can neither speak nor operate a push button. The goal
is for him to use this pointer to select letters on a communication
board. Will this be a problem for the Class 2 laser?

Thanks.
Trish

 

[George Herold]

On Jun 24, 10:28 pm, Patty <bonnypa...@gmail.com> wrote:

On Jun 24, 6:55 pm, Patty <bonnypa...@gmail.com> wrote:





On Jun 24, 6:07 pm, George Herold <gher...@teachspin.com> wrote:

On Jun 24, 4:57 pm, Patty <bonnypa...@gmail.com> wrote:

I have some misgivings about proceeding with a modified Class 2
laser.  Before I'd always read statements like "Eye damage is
impossible with Class 1 lasers even after hours of exposure), due to
their low output power.'  Never a statement about power.  However,
delving into it further to make sure that the 25% reduction of a Class
2 (< 1mW of power) would be the equivalent or better than a Class 1, I
finally found this on the OSHA web site: "Class I: cannot emit laser
radiation at known hazard levels (typically continuous wave: cw 0.4 ľW
at visible wavelengths). . . ."  So I'm now thinking I best try to
make the best of the super bright LEDs, at least 'til I can find a
configuration for the laser pointer that I can determine is, for sure,
safefor my friend.

Thank you again for your kind offer and your help in understanding
this.

Pat

Class I: cannot emit laser radiation at known hazard levels (typically
continuous wave: cw 0.4 ľW at visible wavelengths). Users of Class I
laser products are generally exempt from radiation hazard controls
during operation and maintenance (but not necessarily during service).

On Jun 24, 7:16 am, George Herold <gher...@teachspin.com> wrote:

On Jun 24, 12:52 am, Patty <bonnypa...@gmail.com> wrote:

On Jun 23, 7:17 pm, George Herold <gher...@teachspin.com> wrote:

On Jun 23, 6:51 pm, Patty <bonnypa...@gmail.com> wrote:

I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

Thanks.

Trish

How about a filter over the end of more common laser pointer to reduce
the power?

I'm trying to think of good 'easy' filter.  If you only need a few I
can put a 'piece of plastic' in the mail.  You'll have to cut and tape
pieces over the end of the ~5 mW laser.

George H.

Thanks so much, George!  I'll reply separately.

Trish- Hide quoted text -

- Show quoted text -

Hi Trish,  We sell a bunch of plastic neutral density (ND) filters.
We get big sheets from Tiffin and then chop 'em up... There is always
some edge bits that we can't use and these are just sitting going to
waste on our shelves... These are listed as ND=0.70, the neutral
density is a log of intensity ratio, an ND=1 lets through 10% of the
power,  ND 0.7 lets through about 20%.  But there's plenty of
variation from piece to piece.  I stuck a few pieces in front of a
HeNe laser and had intensity at the output varied from 22% to 15%..

I'm not sure how you are going to measure the intensity of any laser
you might find.
I don't suppose you have a photodiode laying around?

Maybe you can try sticking one or two together and see how you like
it.  I put two in in front of the 0.5mW HeNe and could still easily
see the beam on the wall.

Perhaps the one issue to worry about is too much intensity.   At
higher intensities I've 'burnt a hole' in the plastic.  Not a real
hole mind you but the gelatin that makes up the ND filter changes
somehow if it gets too hot.  I can't give you some hard and fast
number for this intensity as it depends on the spot size of your
laser.

George H.- Hide quoted text -

- Show quoted text -

Yeah, laser's are a bit scary, I wish people would be more careful.

The bit's of plastic are in the mail. If you stack up three of the
filters that will be more than 2.0 ND only 1% of the power will be
coming through.  You can try stacking more.

Part of laser saftey is counting on peoples blink reflex.  Which is
why green laser diodes that leak some of the NIR fundamental are
scarier.  I have no idea if the plastic bits block the 1064 nm light.
See under green here,

http://en.wikipedia.org/wiki/Laser_pointer

George H.

I'll try 6 layers of the plastic with a RED laser.

Thank you, George!

Trish

One more little glitch.  Now I'm Googling for a Class 2 red pointer.
I find a few, but one of them has this warning (no doubt a translation
from Chinese): "The laser can bright enough when you light it in
normal temperature, so you had better do not light it continually in
30 seconds".  Will 'constant-on' be a problem.  My friend (who's a
quadriplegic) can neither speak nor operate a push button.  The goal
is for him to use this pointer to select letters on a communication
board.  Will this be a problem for the Class 2 laser?

Thanks.
Trish- Hide quoted text -

- Show quoted text -

I don't know any laser pointers to recommend.

We use red diode lasers from Quarton.

Something like this,

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=VLM-650-03-LPA-ND

But you have to apply your own power.

Can you do any basic electronics?

George H.

 

[krw@att.bizzzzzzzzzzzz]

On Fri, 24 Jun 2011 19:28:21 -0700 (PDT), Patty <bonnypatty@gmail.com> wrote:

On Jun 24, 6:55 pm, Patty <bonnypa...@gmail.com> wrote:
On Jun 24, 6:07 pm, George Herold <gher...@teachspin.com> wrote:









On Jun 24, 4:57 pm, Patty <bonnypa...@gmail.com> wrote:

I have some misgivings about proceeding with a modified Class 2
laser.  Before I'd always read statements like "Eye damage is
impossible with Class 1 lasers even after hours of exposure), due to
their low output power.'  Never a statement about power.  However,
delving into it further to make sure that the 25% reduction of a Class
2 (< 1mW of power) would be the equivalent or better than a Class 1, I
finally found this on the OSHA web site: "Class I: cannot emit laser
radiation at known hazard levels (typically continuous wave: cw 0.4 ľW
at visible wavelengths). . . ."  So I'm now thinking I best try to
make the best of the super bright LEDs, at least 'til I can find a
configuration for the laser pointer that I can determine is, for sure,
safefor my friend.

Thank you again for your kind offer and your help in understanding
this.

Pat

Class I: cannot emit laser radiation at known hazard levels (typically
continuous wave: cw 0.4 ľW at visible wavelengths). Users of Class I
laser products are generally exempt from radiation hazard controls
during operation and maintenance (but not necessarily during service).

On Jun 24, 7:16 am, George Herold <gher...@teachspin.com> wrote:

On Jun 24, 12:52 am, Patty <bonnypa...@gmail.com> wrote:

On Jun 23, 7:17 pm, George Herold <gher...@teachspin.com> wrote:

On Jun 23, 6:51 pm, Patty <bonnypa...@gmail.com> wrote:

I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

Thanks.

Trish

How about a filter over the end of more common laser pointer to reduce
the power?

I'm trying to think of good 'easy' filter.  If you only need a few I
can put a 'piece of plastic' in the mail.  You'll have to cut and tape
pieces over the end of the ~5 mW laser.

George H.

Thanks so much, George!  I'll reply separately.

Trish- Hide quoted text -

- Show quoted text -

Hi Trish,  We sell a bunch of plastic neutral density (ND) filters.
We get big sheets from Tiffin and then chop 'em up... There is always
some edge bits that we can't use and these are just sitting going to
waste on our shelves... These are listed as ND=0.70, the neutral
density is a log of intensity ratio, an ND=1 lets through 10% of the
power,  ND 0.7 lets through about 20%.  But there's plenty of
variation from piece to piece.  I stuck a few pieces in front of a
HeNe laser and had intensity at the output varied from 22% to 15%.

I'm not sure how you are going to measure the intensity of any laser
you might find.
I don't suppose you have a photodiode laying around?

Maybe you can try sticking one or two together and see how you like
it.  I put two in in front of the 0.5mW HeNe and could still easily
see the beam on the wall.

Perhaps the one issue to worry about is too much intensity.   At
higher intensities I've 'burnt a hole' in the plastic.  Not a real
hole mind you but the gelatin that makes up the ND filter changes
somehow if it gets too hot.  I can't give you some hard and fast
number for this intensity as it depends on the spot size of your
laser.

George H.- Hide quoted text -

- Show quoted text -

Yeah, laser's are a bit scary, I wish people would be more careful.

The bit's of plastic are in the mail. If you stack up three of the
filters that will be more than 2.0 ND only 1% of the power will be
coming through.  You can try stacking more.

Part of laser saftey is counting on peoples blink reflex.  Which is
why green laser diodes that leak some of the NIR fundamental are
scarier.  I have no idea if the plastic bits block the 1064 nm light.
See under green here,

http://en.wikipedia.org/wiki/Laser_pointer

George H.

I'll try 6 layers of the plastic with a RED laser.

Thank you, George!

Trish

One more little glitch. Now I'm Googling for a Class 2 red pointer.
I find a few, but one of them has this warning (no doubt a translation
from Chinese): "The laser can bright enough when you light it in
normal temperature, so you had better do not light it continually in
30 seconds". Will 'constant-on' be a problem. My friend (who's a
quadriplegic) can neither speak nor operate a push button. The goal
is for him to use this pointer to select letters on a communication
board. Will this be a problem for the Class 2 laser?

Most I've seen do have such warnings. I'm looking for a green laser and have
run into this (even with reds, which don't "meet requirements"). This
disclaimer is on the <1mW type and the exact same device in the 5mW class.
Often there is an operating temperature, too. If you stay below that, you
should be able to run them continuously.

I've found that it's possible to "throttle" the laser pointers back by driving
them with a current source. You could sense the temperature and feed this
back to a current source if the limit is exceeded. This will also allow you
to ditch the ND filters. I don't know the ramifications of dimming them yet
(they aren't intended to be used this way). You could also PWM them but this
would show if the laser is moved quickly. Some even have a modulation port.

 

[Jasen Betts]

On 2011-06-24, default <default> wrote:

A similar technique might work with a laser diode and make it much
safer. Diffuse or spread the beam then sharply focus it at 3".
Further away it would spread enough to be safe (depending on his
ability to keep it on target and how close together the targets are)

cheap laser pointers have an adjustable lens that could be
defocussesed that may be enough.

--
⚂⚃ 100% natural

 

[Patty]

On Jun 24, 7:16 am, George Herold <gher...@teachspin.com> wrote:

On Jun 24, 12:52 am, Patty <bonnypa...@gmail.com> wrote:









On Jun 23, 7:17 pm, George Herold <gher...@teachspin.com> wrote:

On Jun 23, 6:51 pm, Patty <bonnypa...@gmail.com> wrote:

I need to make a laser pointer for a profoundly disabled friend.  It
needs only to point 3 inches so I'm looking for a Class 1 laser diode
that will be safe for him despite his erratic movements.  Any help in
locating a Class 1 laser diode that would be appropriate would be
REALLY appreciated.

Thanks.

Trish

How about a filter over the end of more common laser pointer to reduce
the power?

I'm trying to think of good 'easy' filter.  If you only need a few I
can put a 'piece of plastic' in the mail.  You'll have to cut and tape
pieces over the end of the ~5 mW laser.

George H.

Thanks so much, George!  I'll reply separately.

Trish- Hide quoted text -

- Show quoted text -

Hi Trish,  We sell a bunch of plastic neutral density (ND) filters.
We get big sheets from Tiffin and then chop 'em up... There is always
some edge bits that we can't use and these are just sitting going to
waste on our shelves... These are listed as ND=0.70, the neutral
density is a log of intensity ratio, an ND=1 lets through 10% of the
power,  ND 0.7 lets through about 20%.  But there's plenty of
variation from piece to piece.  I stuck a few pieces in front of a
HeNe laser and had intensity at the output varied from 22% to 15%.

I'm not sure how you are going to measure the intensity of any laser
you might find.
I don't suppose you have a photodiode laying around?

Maybe you can try sticking one or two together and see how you like
it.  I put two in in front of the 0.5mW HeNe and could still easily
see the beam on the wall.

Perhaps the one issue to worry about is too much intensity.   At
higher intensities I've 'burnt a hole' in the plastic.  Not a real
hole mind you but the gelatin that makes up the ND filter changes
somehow if it gets too hot.  I can't give you some hard and fast
number for this intensity as it depends on the spot size of your
laser.

George H.

Thank you again, George. Your filters arrived today and I just found a
constant-on Class 2 pen which should arrive 7/6. I'll let you know
how it all works out. &;-)

Trish