PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please sub

[diachi]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

How would they get a TEM00 out of knife-edged 520nm diodes? Even a single 520nm diode doesn't give TEM00.

Corrective optics and a spatial filter will bring them closer. Fiber coupling will be closer again as the fiber homogonizes the beam and provides a nice round output. May be more of a top hat beam, not Gaussian, but far better than the raw, stacked output.

I guess the "near" TEM00 is the disclaimer for those who know the difference. It is a $7,000 knife edged 520nm laser. It isn't possible to get TEM00 out of direct diode lasers, no matter what optics they use. So, what in the world does "near" TEM00 mean?

I'd rather go for this. It can have near TEM00 and they claim the divergence is 1.5 mrad full angle. Ten watt 532nm DPSS laser for $5,980.00

532nm 10000mW/10W DPSS Laser Module/TTL Modulation | eBay

They probably know it isn't TEM00, but they can't really identify the mode so they just say "near TEM00".

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Fiber does bring them far, far, closer together, for some burning work might as well be one TEM00 beam, but for the FAP800 modules, when shining on a wall 10 feet away, you get a pattern of closely spaced dots. However, I am interested in fiber combining several green laser diodes to produce a nice bright beam someday, been thinking about this for awhile, beats the pants off of knife edging.

 

[diachi]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Fiber does bring them far, far, closer together, for some burning work might as well be one TEM00 beam, but for the FAP800 modules, when shining on a wall 10 feet away, you get a pattern of closely spaced dots. However, I am interested in fiber combining several green laser diodes to produce a nice bright beam someday, been thinking about this for awhile, beats the pants off of knife edging.

You get the bundle of dots from the FAP800s becaus they use a bundle of fibers, not one single fiber. The FAP package just has a standard CCP (conduction cooled package) diode array/bar inside of it. They then couple each individual emitter (CCP packages usually have 19 emitters) with a single fiber, then bundle them. That doesn't happen if you stack the beams and couple them to one fiber. Due to the larger input beam/worse beam specs of a stacked beam insertion losses may be higher. You also eventually encounter the limit of the fibers damage threshold, so that only works up to a point.

The pump in my signature does exactly the same, it's just packaged differently.

And a stacked, single fiber combined diode for comparison. 25W output. Diode is a pump for a Yb fiber laser.

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

I saw the thread on those not too long ago, I've been looking at them on ebay, wondering if I bought one whether it could be modified to put green laser diodes in it, but AR coatings and fiber size along with the size of the laser diodes and pain in the arse factor to try to fit it all in there would likely prevent doing so. I love those optics, if they wanted to do so, they could build one for green.

 

[diachi]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

I saw the thread on those not too long ago, I've been looking at them on ebay, wondering if I bought one whether it could be modified to put green laser diodes in it, but AR coatings and fiber size along with the size of the laser diodes and pain in the arse factor to try to fit it all in there would likely prevent doing so. I love those optics, if they wanted to do so, they could build one for green.

Would be easier to build something from scratch using standard diode packages (e.g. 5.6mm, 9mm) and readily available optics/mounts. It'd be larger, but putting it together and aligning everything would be far easier.

Mounting the emitters (And doing the wire bonds), aligning them (and the other optics), adding FAC lenses (look closely) and getting it all going would not be easy for any hobbyist. Not that it isn't possible, just that it isn't practical.

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

I saw a wire bonder on ebay a few years ago, almost bought it.

Edit: Yikes, just looked, there are lots of them, but hobbyist priced? Not so much.

https://www.ebay.com/sch/i.html?_od...re+bonder.TRS0&_nkw=gold+wire+bonder&_sacat=0

 

[diachi]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

I saw a wire bonder on ebay a few years ago, almost bought it.

Not sure what the procedure/requirements for LDs are off the top of my head.

At home mounting and bonding/wiring of LD chips certainly can be done, although not to the same standards as a professional/commercial environment.

One issue would be mounting LD chips that have been mounted to a package already (i.e. all of the green LDs we have access to). I'm not aware of any source offering just the LD chip.

Sam's FAQ has some information on mounting bare chips.

Krazer also has some details on his website/blog - he's managed it with decent results. Although, again, not up to commercial standards.

laser diode mounting

 

[ultimatekaiser]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Generally the diode is mounted in a mount with telescoping focus lenses, one being aspherical to compensate for one axis, then prisms are used to correct for the other axis, resulting in a (mostly) circular laser beam. I'd have to see if I have pictures of my RCS setup. I have some of those 40W diode bars that have lenses on the end to focus it and correct for the divergence of the bar.

 

[paul1598419]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

I bid on and won one of those auctions for the cylindrical lens trios in the 445nm range. It has been shipped out now. Has anyone else gotten one of these yet?

 

[lazeristasUVISIR]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

I've been watching this little YAG for awhile now, I keep thinking it is too small to produce much power, am I wrong? Anyone care to make an educated guess on a reasonable expectation for output power when end pumped with 808 nm?

Tiny YAG rod 2.5mm dia. x 5.2mm long Plano cvx 15mm Spectra physics AR HR coated | eBay

2cnts: it is a mirror ( -15 mm in a description). It would be a very bad practice to miss a dopant and its concentration on a label.

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

2cnts: it is a mirror ( -15 mm in a description). It would be a very bad practice to miss a dopant and its concentration on a label.

IDK, those coating specs sure look like for a end pumped YAG, anyone?

 

[H2Oxide]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

IDK, those coating specs sure look like for a end pumped YAG, anyone?

They absolutely do, and there's nothing saying that you can't have a curved mirror on the end of a gain crystal.

That being said, you're not going to be able to build a very efficient laser if you don't even know the doping concentration of your crystal. It's obvious from the pictures that it's not a very standard concentration (like 0.5-1%) if it's doped at all, so you would be completely guessing at the majority of the specs for your laser. It might be worth asking the seller if he knows.

 

[Alaskan]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Seller said he was going to send one to me for free to check, he knows I'm out of country away from home and it will be awhile. I'm interested in small YAG's, this is very small, probably too small for what I want. If I'm going to build a 532 nm DPSS pointer (in a large package, with my skills) I want at least 1.5 watts out, this probably wouldn't generate enough 1064 nm to do that, I'm guessing.

 

[ultimatekaiser]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

15mm is more than enough to get many watts out generally speaking if it is well pumped, but you'd have to have a well designed cavity, and have it temperature regulated. Would be difficult to end pump something that long, and thermal lensing would be a big issue.

 

[RedCowboy]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Here it is, half an amp in @ 7.4 should be good for what? 50mw of 520nm?
Whatever it is for 20 bucks I can't pass it up.

A lot of specs get mixed up with LL, they always do that, this may need to be tuned by the end user, I think someone did a review before, anyway sale ends in 11 hours.

5mW 520nm Green Portable Laser Pointer Point Pen Laser Diode Pointer Osram LD in | eBay

 

[GSS]

Re: PERMANENT THREAD: Ebay& other internet FINDS of interest- read all the OP please

Here it is, half an amp in @ 7.4 should be good for what? 50mw of 520nm?
Whatever it is for 20 bucks I can't pass it up.

A lot of specs get mixed up with LL, they always do that, this may need to be tuned by the end user, I think someone did a review before, anyway sale ends in 11 hours.

5mW 520nm Green Portable Laser Pointer Point Pen Laser Diode Pointer Osram LD in | eBay

This is the unit LaserLand gave to 5 members
They were measured at 5mw to 8mw but I believe "CynicalBrad" potted it to 40mw+? but could of pushed it further I think?
You will like this unit:beer: