"More Beam"

[Lasher]

Greg,

The only problem I've had with it is the button is a little picky sometime and you may have to push it more than once to get it at full power.

I never run my more than say 90sec at a time then let it rest for 25-30sec so as not to over heat it.

It seems to get brighter after its been used a few times but its really built far better than what you would expect for 22 bucks.

It came straight from china and took me I think about 12 days to get it.
I remember it came quicker than I was expecting and I missed the mail man and had to pick it up at the Post Office.

I'm in Oak Ridge btw so were not that far apart. I've got a rather nice Laser on the way to me as we speak maybe after I get it I can come by and let you check it out on some night when its not pouring rain like it has been here for the last 6mts....lol

Hope you enjoy your new laser

Lasher

 

[Things]

That's correct, but something has been wondering me lately. Does the crystal actually "double" the frequency? I have heard that Green DPSS lasers use a diode putting out 808nm, not 1064nm.
But I'm not sure if that's true.

Thanks,
Moptsp

DPSS doesn't use a crystal that magically converts IR to green, it's the actual crystal itself producing the green light, the IR is just there to PUMP the crystal (Diode PUMPED solid state).

 

[randomlugia]

Sorry I was unclear about the whole brightness thing, I just meant that 50mW could be a bit overwhelming for starpointing and takes away your night vision a bit.

 

[Moptsp]

DPSS doesn't use a crystal that magically converts IR to green, it's the actual crystal itself producing the green light, the IR is just there to PUMP the crystal (Diode PUMPED solid state).

Yeah I learned a few years ago that magic doesn't exist lol.

I get what your saying and it makes sense (this is how I see it too). I was just asking if the frequency is actually doubled because wouldn't doubling the frequency of 808nm make it 404nm? So wouldn't that be a 1.5188[...] times frequency rather than 2?

Again, just asking questions, not stating anything.
-Moptsp

 

[maxh]

Yeah I learned a few years ago that magic doesn't exist lol.

I get what your saying and it makes sense (this is how I see it too). I was just asking if the frequency is actually doubled because wouldn't doubling the frequency of 808nm make it 404nm? So wouldn't that be a 1.5188[...] times frequency rather than 2?

Again, just asking questions, not stating anything.
-Moptsp

The 808 pumps a Nd:YAG crystal which emits 1064 nm laser light of higher quality than the 808 nm laser light coming out of the diode. This 1064 is then frequency doubled in another crystal to make 532 nm.

 

[ElektroFreak]

DPSS doesn't use a crystal that magically converts IR to green, it's the actual crystal itself producing the green light, the IR is just there to PUMP the crystal (Diode PUMPED solid state).

Not quite true. The only crystal in a frequency-doubled DPSS laser that produces it's own light is the laser crystal itself, the Nd:YAG or Nd:YVO4. The doubling crystal (KTP in the case of most greens) converts the incident 1064nm light to 532nm by way of a non-linear optical process.

The way green DPSS lasers work is like this

Pump diode (808nm) pumps Nd:YAG/Nd:YVO4 (produces it's own 1064nm light when pumped with 808nm light). The 1064nm light is then converted to 532nm light by the non-linear crystal (KTP).

EDIT: OOPS... didn't see your post maxh..

 

[mfo]

Not quite true. The only crystal in a frequency-doubled DPSS laser that produces it's own light is the laser crystal itself, the Nd:YAG or Nd:YVO4. The doubling crystal (KTP in the case of most greens) converts the incident 1064nm light to 532nm by way of a non-linear optical process.

The way green DPSS lasers work is like this

Pump diode (808nm) pumps Nd:YAG/Nd:YVO4 (produces it's own 1064nm light when pumped with 808nm light). The 1064nm light is then converted to 532nm light by the non-linear crystal (KTP).

EDIT: OOPS... didn't see your post maxh..

Yeah that's what I thought. I mean how would a crystal produce a laser beam lol. I figured the crystal bent the light waves into green.

 

[ElektroFreak]

Yeah that's what I thought. I mean how would a crystal produce a laser beam lol. I figured the crystal bent the light waves into green.

There are actually two crystals in a frequency doubled DPSS laser such as a greenie. One crystal does in fact produce its own laser beam when you pump it with an 808nm diode. The other crystal changes the frequency.

 

[mfo]

There are actually two crystals in a frequency doubled DPSS laser such as a greenie. One crystal does in fact produce its own laser beam when you pump it with an 808nm diode. The other crystal changes the frequency.

Yeah, I know. 808 -> 1064 -> 532. But I was under the impression that each crystal (denoted by the ->) just bends the light into the next frequency.

 

[ElektroFreak]

It would be nice if it were just that simple, but there are very advanced physical principles at work in DPSS lasers. The reason we need to pump a laser crystal and have it produce its own beam is because the beam the it produces has far superior qualities when compared to diode output alone. We need these superior qualities to get the most efficient conversion to green. It is possible to convert a diode directly, but due to the crappy beam produced by diodes it is a VERY difficult thing to do and requires a lot of money and know-how.

 

[Moptsp]

The 808 pumps a Nd:YAG crystal which emits 1064 nm laser light of higher quality than the 808 nm laser light coming out of the diode. This 1064 is then frequency doubled in another crystal to make 532 nm.

Now the math adds up, thank you! Now that you said that, I do remember seeing two crystals is DPSS laser diagrams.

Thanks,
-Moptsp

 

[mfo]

It would be nice if it were just that simple, but there are very advanced physical principles at work in DPSS lasers. The reason we need to pump a laser crystal and have it produce its own beam is because the beam the it produces has far superior qualities when compared to diode output alone. We need these superior qualities to get the most efficient conversion to green. It is possible to convert a diode directly, but due to the crappy beam produced by diodes it is a VERY difficult thing to do and requires a lot of money and know-how.

Crazy. Never knew it was that detailed.

 

[Gsquared18]

Ok the voices in my head won't leave me the heck alone and keep screaming "You're never gonna get your laser from Led Shoppe and it's probably gonna die on ya anyway" so I gave in and ordered another one.

You see, one of the users here recommended Led Shoppe's 50mW so I ordered one last weekend but the voices & I fear that for $22, I got what I paid for. I saw that the website had a Minnesota address so I assumed it was shipped within the U.S. But after the item shipped, they sent an email stating it'll arrive via Air Mail in 7-20 days and now nobody from the company which seems to operate out of CHINA will get back to me on what that really means. On top of this, I'm extremely impulsive and would never purposely wait nearly a month for something to arrive unless it's a new car or the lump sum check of a $200,000,000 lottery winning but since it ships for free, I guess they want you to appreciate that and then sit on your duff and wait.

So just as a backup and what I should have done in the 1st place, I just ordered a "Premium +55mW Green Laser Pointer" from Optotronics and holy cow, an American answered the phone and said it'll be here Monday (today is Friday). Based on that phone call alone, it's worth every penny I just spent on it even if it's a box of rocks. Well... you know what I mean. Anyways, Thank you Optotronics!!!!

 

[Gsquared18]

Yahooo! Just got the Premium +55mW in the mail. Ordered it Friday and got here Monday and still waiting on the one from Led Shoppe. Put in a couple AAA batteries from a tv remote just to test it and although I didn't buy it as a burner, it's not burning at all. May be the batteries but if not, no big deal. I'm going to buy some AAA recgargable batteries but do I have to stay under a certain mAh limit or get the biggest ones they got?

 

[Moptsp]

Gongrats!

A 55mw wont do too much burning (if any). You could still aid it a bit (use a lens) to burn, I think, though.
I could be wrong, but I'm pretty sure that's the case.

How is the beam at night?

Thanks,
Moptsp

 

[Deleted member 8382]

Honestly, now that you got a 55mW pointer, take another 99$ and buy this:

Rayfoss

yes, it's gona take 3 weeks for them to get on your mail, but I ensure you after comparing you will regreet the optotronics buy for the same cash.

Ofc Optotronics is a great company with great products, but as long as you don't want a very high output laser, you can stick to the chinese builds for under 200mW green lasers without fear.

I own a 200mW green focusable laser that works like charm and only costed me 150$!

Yours,
Albert