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my new homemade beam expander

Ainus

Member
Joined
Jan 9, 2019
Messages
90
Points
18
about ayear ago ı started to making beam expenders but all of then turn out to be total garbage because they significantly drop the total ligth but today ı made a new one from 70 mm porro prism binoculars and this is the best beam expander that ı did so far because it doesnt realy drop the output but its extremly ugly and very large WhatsApp Image 2020-12-01 at 00.27.02.jpeg
beamshotsWhatsApp Image 2020-12-01 at 00.27.02 (1).jpegWhatsApp Image 2020-12-01 at 00.27.01.jpegWhatsApp Image 2020-12-01 at 00.27.02 (2).jpegWhatsApp Image 2020-12-01 at 00.27.02 (3).jpeg
divergence on this setup is suprisingly low
beam at output is 70mm beam at 400m away is 100mm
ı hope its not illegal to own laser with extremly tigth beam
 





Joined
Jun 3, 2007
Messages
2,560
Points
113
Measure the Rayleigh Length. Measure from the front optic. Then find the point where the beam starts to expand.
 

gazer101

Well-known member
Joined
Feb 23, 2020
Messages
700
Points
63
I wonder what kind of beam specs you'd need to deliver a signal to Mars via laser
 

gazer101

Well-known member
Joined
Feb 23, 2020
Messages
700
Points
63
Not bad! Just gotta get in touch with a glassblowing to make my large lens and I'm set
 

Ainus

Member
Joined
Jan 9, 2019
Messages
90
Points
18
Confirm by actually measuring with a tape measure.
Because of the pandemic ı cant mesured back then but last weekend and focused the laser alot better with my telescope and ı mesured with a tape nad here is the resaults beam after 1km is 142 mm and olso squere shaped not rectagle at the start beam is litle under 70 mm and its rectangle like nomal direct diode lasers

Note: Distance could be bit les than 1000 meters like 950 m but its around there I mesured with google earth
 




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