50mW NDB7242E Vs A150

[Deleted member 16589]

Ok so I decided to put this in its own thread rather than add it to my group-buy thread.

this is a quick comparison/review of the NDB7242E diode

So after the diodes from my groupbuy arrived I quickly through together a driver kit i had laying around.

Using the Test points i set the driver to ~120mA

I then metered the diode

Now came the tricky part I wanted to compare the raw output of the diode compared to an M150Ii had, But had trouble photographing it.
after some playing around I figured it out.

I projected the raw output on a piece of white printer paper and using the HDR setting on my camera I took a picture of the spot from the backside.

Standard A150

NDB7242E diode

I found that the lense crops off those splashes on the edge of the spots.
this is the spot at 11 feat with a 3 element lens unfocused

Now I set up both lasers to shine at the wall 11 Foot away and focus both as small as i could. (not sure if that's the best way to compare? )

using the red filter for my camera seen in above image, the spots at 11fT

the NDB7242E diode on the left A150 on the right.

Update 7/22/14

Testing at ~28 feet (333 inches to be exact)

Mother of epic

Someone please check me when they get there diode lasing.
I calculated the divergence at .15 mRad

these are the measurements I took for the fast axis.

Distance I (m): 0 (at aperture)
Diameter I (mm): 1.96
Distance II (m): 8.4582
Diameter II (mm): 3.19
Divergence (mRad): 0.15

Update 2 so after that testing I was told to do it at a farther distance.
Brought my laser and Bench PSU outside and shined it on our pool-deck. It measures 65Ft 2 inches away.

at that distance the fast axis measured 9.37mm

and finally a beam shot.

 

[IsaacT]

I was under the impression that these were going to be single mode diodes like the ones DTR has...

 

[Deleted member 16589]

Nope it was stated several times throughout the thread and in the spec sheet that these are multi mode. But man these almost look single mode. I just did a distance test with my 20mW 635 and man the divergence is good Ill try to ad more later.

edit I'll calculate the divergence later.

 

[crazyspaz]

I swear I read single mode as well....thats a little disapointing, but the divergence looms good enough that it shouldnt matter. I only regret not getting 2 :/

 

[ZRaffleticket]

I remember reading the GB thread, which I'm not even a part of, and remember these being compared to the newer 520's, which are in fact multimode but are barely more divergent than single mode.

Guys, multimode doesn't mean it'll be bad. Guys. Guys....

 

[crazyspaz]

What? I thought that multimode diodes, just lime guns and vaccines, are the devil :thinking:

 

[ARG]

Remember the summer of 445nm when people were hesitant to buy the diode because they thought they would be flashlights? Yeah.

 

[crazyspaz]

I hope these will have good results with the new lenses from the GB that just took place. If it ends up having crappy wings, I will be pretty disappointed- I was hoping for a nice, ~100mW tight beam. Nothing I can do about it now, I suppose

 

[Deleted member 16589]

even with the wings this is a nice tight spot. most of that splatter outside of the wings are from the crud on my lens it sat on my computer for months.
I got my diode for an RGB build I'm making but now I want a pen with this diode . :tinfoil:

 

[Deleted member 16589]

Update
I have moved some posts to the OP and added testing at 65fT :beer:

 

[crazyspaz]

that divergence is just ridiculous. I'm waiting on the x-drives to be restocked, then I will put mine together.

 

[Deleted member 16589]

The strange thing is the slow axis converges after the lens wile the fast axis expands. Because of this I have been told on Laserchat that the beam is not truly collimated. But if I correct the slow axis the fast axis is terrible. so I'm not really sure whats happening.

 

[Trevor]

From the video description:

65ft 2 inches =165.166667 ft
165.166667ft = 50.3428001016 meters

There's your problem!

Converting 65 feet to meters (instead of 165 feet), you end up with 0.36mRad... which is still quite good.

Trevor

 

[Deleted member 16589]

From the video description:



There's your problem!

Converting 65 feet to meters (instead of 165 feet), you end up with 0.36mRad... which is still quite good.

Trevor

Face-palm

anyway here is the video he was referencing.