[Laser] Chucks question continued

[Chuck Hast]

Jim,
Looks like I missed something did not see anything from Mike just saw
your response. Is it some sort of spectrograph or spectrometer?


On Mon, May 14, 2018 at 11:32 PM, Jim Moss <n9jim-6 at pacbell.net> wrote:

> Mike,
> Looks like that is pretty cheap.
> Looks like it is about 3nm resolution, and about 2 month delay to shipment.
> You have to calibrate it yourself.
> Might be interesting.
> Let us know how it goes.
> Jim
>
>
> Sent from my iPad
>
> > On May 14, 2018, at 8:08 PM, Chuck Hast <wchast at gmail.com> wrote:
> >
> > Jim,
> > That did it. Now to go through it and get it into a stand alone little
> > piece of
> > say python code. A good exercise for me...
> >
> > Then the larger angle was probably what was taking a bite out the
> numbers in
> > the original calculation using the formula that you indicated was doing
> the
> > approximation.
> >
> >
> >> On Mon, May 14, 2018 at 8:21 PM, Jim Moss <n9jim-6 at pacbell.net> wrote:
> >>
> >> Chuck,
> >> It looks like we may have sin and tan issues here
> >>
> >> Original cited article:
> >> http://laserclassroom.com/products/measure-wavelength-laser-light/
> >>
> >> The angle based on your data is arctan(627/1000) = 32.08771207 Degrees
> >> That’s diffraction distance (X) / distance to target (L)
> >>
> >> The grating equation is WL = d sin(32.08771207), d=1000/mm
> >> Or 531.2 nM.  That matches your laser source.
> >>
> >> Note that in your original cited article approximates sin = tan.
> >> This is true when the angle is small, but introduces errors at larger
> >> angles.
> >>
> >> Here’s a calculator for the experiment: not using the approximation.
> >> http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/gratcal.html
> >>
> >> Jim
> >>
> >> Sent from my iPad
> >>
> >>> On May 14, 2018, at 5:40 PM, Jim Moss <n9jim-6 at pacbell.net> wrote:
> >>>
> >>> Chuck,
> >>>
> >>> After rereading, I think my statement on d is not correct. It may be as
> >> simple as 1 mm/1000. See link below to Newport.
> >>>
> >>> Could the error be related to that you are not reflecting directly off
> >> the grating surface? The experiment shows sending the beam thru the
> >> grating? If so, could there be an angle error induced?
> >>>
> >>> Could it be that the grating is facing the wrong way? Thus creating an
> >> offset due to the medium thickness of the grating material?
> >>>
> >>> Good summary on defraction gratings.
> >>> https://www.newport.com/t/grating-physics
> >>>
> >>> Jim
> >>>
> >>>
> >>> Sent from my iPad
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> >
> >
> >
> > --
> >
> > Chuck Hast  -- KP4DJT --
> > I can do all things through Christ which strengtheneth me.
> > Ph 4:13 KJV
> > Todo lo puedo en Cristo que me fortalece.
> > Fil 4:13 RVR1960
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-- 

Chuck Hast  -- KP4DJT --
I can do all things through Christ which strengtheneth me.
Ph 4:13 KJV
Todo lo puedo en Cristo que me fortalece.
Fil 4:13 RVR1960