Anyone have info on the Lumenis Novus Spectra?

[Alaskan]

I've bought a few things from him on ebay over the years, I somehow had the impression he was mostly retired now though.

 

[kecked]

Steve is just busy. We talk often. He has not mentioned any issues. Trust me he’s the kind of person who will let you know when there is a problem. Work has him swimming in broken devices that students abuse. I’ll mention to him your looking for him/. I’ll see him in about 2 hours time. We are working on something. He local to me so I’m spoiled. Where do you think I learned what I know as little as it may be.

 

[Alaskan]

OK, thanks. Not retired then. Teaching on his own, or a university?

 

[kecked]

Still. Very much a working stiff like all of us. He’s not even close to retirement age. And that’s the last I shall speak for him.

 

[paul1598419]

I also got the impression he was still every active and working with lasers daily. A very nice guy, from the little interaction we've had.

 

[Alaskan]

Steve, can you give me some insights in regard to SHG from a 808 nm FAP, what if the FAP is 806 nm, or 807, 810 nm, how much does being off of the 808 nm affect the output at 1064 nm from a YVO3 crystal? Here is a dumb question, would it even be 1064 nm? Perhaps the YVO4 puts out 1065 nm, if 808.5 nm input? Anyone else, please feel free to answer if you know. I should know the answer to this, but I don't.

 

[diachi]

Steve, can you give me some insights in regard to SHG from a 808 nm FAP, what if the FAP is 806 nm, or 807, 810 nm, how much does being off of the 808 nm affect the output at 1064 nm from a YVO3 crystal? Here is a dumb question, would it even be 1064 nm? Perhaps the YVO4 puts out 1065 nm, if 808.5 nm input? Anyone else, please feel free to answer if you know. I should know the answer to this, but I don't.

AFAIK being off the absorption band will only impact overall efficiency. Output wavelength should remain unchanged.

 

[kecked]

The window on Nd yag is about 1nm wide. It’s not a sharp drop but pretty steep. Yvo4 is wider
Not being an ass but google it. Tons of instant info in far more detail than I want to type

To some extent moving pump moves output. Wiki has some good stuffwatch a cheap pointerwarm up. As the pump heats the wavelength drifts. And the efficiency goes down

 

[paul1598419]

That is my understanding as well. As the pump drifts it can have an impact on overall efficiency, but the lines out remain constant in their wavelengths. Tuning the output can select the particular line you would like to get out of it, but those lines are all there is, or at least that is how it is supposed to work.

 

[kecked]

DPSS Laser Pointers, question regarding why they are unstable....Diode WL, YVO4, KTP?

Curious what the main problem is which causes our 300-800 mw 532 nm laser pointers to have varying output power (well, for that matter, just about any power DPSS laser pointer). Is it the diode going too far away from the 806-812 nm acceptance wavelength window for the YVO4 crystal to produce...

laserpointerforums.com

nice write up.

I agree with you paul. I'm wrong. What I was thinking of was the multiple wavelengths we see from the cheap dpss lasers not that it drifts around. My bad in what I was saying vs thinking. The pump determines efficiency and the temp of the ktp the power of the output not wavelength. Coatings can affect what you see in terms of lines produced..

 

[paul1598419]

The reason I said that is the way it is supposed to work is because I found a 532nm YVO4/KTP based pointer that would drift in wavelength as it warmed up. I was looking for multiple line pointers, so I was watching them on my spectrometer and one would drift up in wavelength as it warmed up. I can't explain this effect, but don't believe it was due to a fault with my spectrometer as there was only this one that did this.

 

[LSRFAQ]

So I put on my Senior Engineering Technician, Grade Two, hat...


I've been off working on something, 12 years till retirement. Due to budget and staff cuts and buyouts of professors for early retirement, I have roughly 100 grad students who can "ring my bell" and I look after the teaching facilities for ~300 undergrads. That and my machinist partner in crime is off on sick leave for another few months. I get loaned out to other programs. So forgive me for not replying sooner, but I was off building Kecked's new odd ball laser in my friend's machine shop just to get my mind off work. That and my cousin passed over the weekend. Toss in that I'm sole caregiver for a 87 year old. The student robotics team's new chief engineer just grabbed what Sunday was left, , and one does not argue with EE students when they want to set your chem eng robotics team lightyears ahead. She's a good egg, had pizza waiting for us. The Rector went way long on his sermon on Sunday, set a new record for his personal best "long time", like almost an hour and a half, so I didn't see the net. Then mom said, " I want a fish dinner, all I can eat, you can come too, and pay the bill" so there went Sunday night except for testing some cavity optics and reading papers on stokes shift to alternative wavelengths while she chomped down that whitefish.

I be busy... Its not my choice, its just what I have to do to serve others and survive.

OK, first thing to do is I'll ring up Kevin at Starlight Photonics and ask him what he has in used ~25 amp drivers. I'll Ask him if he has another of the "blue box supplies" which was a nice box with two massive TEC controllers and a very nice diode driver with a LCD on it. He does not let those go to just anyone, they are/were test rigs for Really Big DPSS Lasers Inc, so I'll email him right now and tell him your trying to join the big leagues and see if he has another. He keeps them, rightly, for bench test of the cool stuff he sells.

If you had set me off, you would have known, or more precisely I'd have some one we both know call you. I am not a bastard, I am THE BASTARD when I'm angered.

Long standing joke at work.. Prof walks up and says Steve, your behind and again and look tired... Then he says, "Steve, have you been taking the time to eat again? " I get a sad look on my face and nod sheepishly. Then he says, "I bet you were sleeping, too. Your not supposed to sleep" I nod my head and look down in shame... The punch line is unspoken and everybody laughs.

OK, my afternoon 15 min break is over and a grad wants to know how to make flexible graphite seals for a red hot glowing oven... At least when he texted me at 10 Pm last night he needed it ASAP. Its 3:30 and I'm just getting to him after training a student on confocal microscopy, where I take really good care of a 559 nm DPSS.

Off I go. I'm surprised pointer dudes and dudettes do not know about Grafoil...

Chris, your looking for a range of quality driver that does not come cheap. If he does not have another blue box, Silicon Valley Surplus on Ebay gets lots of the right one, just half are duds when they get here for test... I need to find one for you.... Its big enough to have a friendly serial port for diagnostics, and you'll need a 1 Ohm 200 watt resistor and three 40 amp silicon diodes to test it.

 

[kecked]

He lives!

Paul yea I have seen them float around too and I always just thought the pump was floating around. Digging deeper I don't see that as the cause. Maybe the KTP temp can do that to some extent. I really just don't know. An atomic transition is pretty stable. The variability could only come in the doubling stage.

Here is a guess https://www.osapublishing.org/Direc...3-17-22765.pdf?da=1&id=324479&seq=0&mobile=no

raman shifting and side product mixing

 

[LSRFAQ]

Hold up your left hand with palm toward you. The ND:YAG Adsorption curve at 808 is a series of spikes about 1.5 nm apart that looks like your fingers. Oh, Wait, I found one. This is when pump diodes in cheap lasers are really heated up you see a bright, dim, bright, dimmer, not so bright, dim, sequence as they are warmed up,

KTP goes through some small peaks as it reaches a stable temperature, too.

 

[LSRFAQ]

Gain bandwidth on ND:YAG is 1.5 nanometers at 1064.1 and there is a second weak line at 1066 or so that has a similar gain bandwidth. They just overlap a bit. As the KTP warms up it acts as a birefringent filter and tends to select a wavelength. So you may, and I HAVE seen it, drift in wavelength. Just be glad they do not make your pointer out of ND:GLASS, because that has a very wide gain bandwidth, 27 nanometers in a Phosphate glass rod. If your making a very big amplifier rod, you'd like to have that wide gain, and for good reason.

Vandate has a wide gain too, not as wide as the glass, but still wide. Its not your spectrometer. It is the fact that the maker of cheap lasers will choose whatever the cheapest crystal they can order any given week that meets their requirements. "Does it Lase well?" is about the only requirement.

We once tried a demo of a very famous brand single frequency laser at my work. It was single frequency alright, very nice narrow line, that slowly slid back and forth across that 1.5 nm of gain bandwidth over periods of ten minutes or more. After a 24 hour test in a controlled room with very controlled conditions, watching the drift measured in units of picometers, I heard "Too Bad, Now get me another replacement Argon tube". Better to deal with 10 Ghz of bandwidth vs a few nm when doing Brillioun Spectroscopy with 48 hour exposures. A few years later I was working on a laser that could digitally control the etalon to select about 30 frequencies out of that 10 Ghz bandwidth.

So it really depends on how you define "single frequency"



Quiz of the day, Why do you sometimes see a tiny amount of 537 from a high power cheap 532 nm pointer?

Steve

 

[paul1598419]

I do appreciate all the confirmation of my observation as I have taken flack over it before. I was only reporting it as it seemed odd to me at the time. But, I was told my spectrometer or my procedure were defective and I did not see what I had claimed.