Another project red?

[shrad]

you have to take plano-convex lenses with focal lengths with the same ratio as the telescope (for example a 3X telescope will need a 3cm focal length and a 1cm focal length) and superpose the focal points, basically

(correct me guys if I'm wrong here)

[danielbriggs]

What is, by approximation, the distance needed between the lenses for a nice result ?

Try this:
http://webphysics.davidson.edu/physl...ics_bench.html

Use nominal figures. e.g. Add a beam, add a convex lens X=1.00, fl=3.00, add another concave lens, X=3.00, fl=-1.00.
You could use two convex lenses, but overall telescope length would be increased. e.g. X=5.00, fl=1.00

Dan

[hobbybob]

Thanks Dan, excellent link which allowed me to play with the lenses.
But does this really mean if i come in at 6 mm diameter i can bring it down to 2mm with very little divergence using a 3:1 telescope ?
Sounds too good to be true...

[danielbriggs]

Divergence increases as diameter decreases by same factor. Steve (MixedGas) posted the technical description for this (and whether which way round worked or not - can't remember). Also can't remember the thread...

[daedal]

@DDL: any info on the PBSes and drivers ?
PBS: Transmission/reflection losses, for what colors etc ?
Drivers: positive / negative drivers ? Max. drive current ?

looking forward seeing more info on them. Cool addition to your shop !

They are now on the site and available.

I've measured the PBS's to have <5% loss. I've got PBS's for 405, blue, and red. They measure 0.5".

The drivers are positive, and will supply up to 400mA with full analog modulation. I've used these drivers and am very pleased with the results. The price is not bad at all either

--DDL

[daedal]

I want to add another one to the mix... another lens that is...

http://www.thorlabs.com/thorProduct....mber=C110TME-B

What do you guys think?

--DDL

[edison]

If anyone is looking for a driver have a look at the bottom of this PDF:

http://www.versatis.nl/download/Shortform%20catalog.pdf

It,s an 8 diode drver with 2 amps per driver on one board. Its easy to miss so scroll slowly :-)

I tried to contact the company but i didn,t hear from them yet. Hopefully someone here want to pick it up from here and get a price from them. The company is B&Wtec


info@bwtek.com www.bwtek.com

[p1t8ull]

I want to add another one to the mix... another lens that is...

http://www.thorlabs.com/thorProduct....mber=C110TME-B

What do you guys think?

--DDL

I tried to read the blurb but my eyes kept darting back to the £60 GBP price tag and started watering profusely

[edison]

As the search goes on for the perfect lens maybe this is something:

http://www.egismos.com/support/laser...O1-CO-6Mv2.pdf


Specifications(typical@tc=25℃)
Item. symbol O1-CO-6.5-8.9-M O1-CO-6.3-9.8-M
Material Glass (OHARA L-TIM28) Glass (OHARA L-BAL42)
Operating Wavelength λ 600~810nm 630~850nm
Numerical Aperture NA 0.29 0.17
Effective Focal Length EFL 8.9mm 9.8mm
Working Distance
(Back Focal Length)
WD
BFL 7.55mm 8.25mm
Collimated Beam Size ≤6mm at 10m ≤8mm at 10m
Collimated Beam Divergence 0.2~0.3mrad ≤0.3mrad
Wave Front Error ≤0.05λ (635nm) ≤0.04λ (780nm)
Outer Diameter OD (φ) 6.50mm 0/-0.03mm 6.35mm±0.02mm
Clear Aperture
(Effective Diameter) CA 5.2mm (R1)3.5mm (R1)
R1 Φ5.2mm / R2 Φ4.6mm R1 Φ3.5mm / R2 Φ3.0mm

Center Thickness CT 2.36mm±0.03mm 3.00mm±0.02mm
Transmission (AR Coating) Tr ≥97%(635nm) ≥97% (650nm,780nm)
Operating Temperature -40℃ to +160 ℃ -40 ℃to +160 ℃
Storage Temperature -60 ℃to +200 ℃ -60 ℃to +200 ℃
Surface Quality
(Mill Standard) 60/40 60/40

[logsquared]

Update on my combiner project.

FU*K! how many diodes can a person kill in one day? Finally got the mounts machined for the 8 diode test combiner. Only have 4 diodes at the moment. That's cool, i will just put them on the four "corners". Put 2 in to get started then go ahead and ground the chassis with a high side driver. Doh!! now i only have 2 diodes to work with.

Good news is the 4-40 screws have enough resolution to aim and overlap the beams at a distance. The initial idea seems to work. Now I only need to make a small change to the mirror holders to allow more movement in the +X direction. pictures coming soon.