Air ionization from a pointer-sized laser (standa STA-01-8-1047): How do they do it?

Hey! I'm new around these forums, but I think I already know a fair amount of laser terminology, so don't be afraid to get technical.

I came across this the other day:
Passive Q-Switched Laser - Lasers & Laser Accessories - Catalog - Opto-Mechanical Products - Standa

Youtube:


It seems rediculous that a system that small could create air ionization. The closest laser of compriable size that I've seen had the dimensions of a toaster and could only fire in single shot mode.

Does anybody have any idea how this thing works? What do you think the pump diode is? I would love to hear any thoughts on how the actual system is set up.

In all honesty, I think it would be awsome if I could try to build one of these. It is probably extremely expensive and would be cheaper to build one yourself. I just need some advise from the professionals.

Here are some stats from the website:

Wavelength, nm 1047
Pulse energy, µJ 600
Average output power (max), mW 60
Pulse width (FWHM), ps 500
Repetition rate (max), Hz 100
Pulse to pulse energy stability (RMS), % <0.5
Beam profile TEM00, M2~1.25
Beam waist diameter inside the laser head 1/e2, µm 160
Pulse spectral structure SLM
Spectral linewidth (FWHM), pm <3.5
Polarization ratio >100:1
Interfaces USB, External trigger (TTL rising edge)1Hz...max repetition rate
External power supply voltage, V AC 100-240
Operating temperature, °C 15 - 40, non-condensing
Laser head dimensions, mm Ø25x74
Controller dimensions, mm 223 (W) x 94 (H) x 197 (L)

Also, it said that it came with a built in "Frequency generator". What is this and how does it control the frequency of the pulses?
:thanks:

It looks like my Youtube window wasn't working, so here is a link:
Passive Q-Switched Laser - YouTube

It is NOT a pointer-sized laser. Note the box in the background. It's just the head that's pointer sized. If I had to guess, I'd say everything except the Nd:YLF is in the box behind. Pump is then fed through a fiber to the head. The average power is 60mW, so it doesn't need to be massive.

I thought the big box was the power supply to get the electricity from the wall down something more manageable. If it is a fibre, then why run it all the way to something that looks like a pointer? Doesn't make more sense to just have the entire system built as one box? Considering that it has two wires leading to it, it would make sense that one is for power and the other is the fibre. No matter what, it's still a pretty nice system.

Even if this isn't pointer sized air ionization, the most important question would be: is air ionization even possible from a pointer size laser?

This might be completely wrong, but shouldn't pointer sized air ionization be easy since the average output power is only 60mW. I've seen pointer sized systems capable of much higher outputs that 60mW, although they were in CW and not pulsed output.

SirRej said:

I thought the big box was the power supply to get the electricity from the wall down something more manageable. If it is a fibre, then why run it all the way to something that looks like a pointer? Doesn't make more sense to just have the entire system built as one box? Considering that it has two wires leading to it, it would make sense that one is for power and the other is the fibre. No matter what, it's still a pretty nice system.

Even if this isn't pointer sized air ionization, the most important question would be: is air ionization even possible from a pointer size laser?

Click to expand...

Ehhh. Neurp. When you've got an entire optical system to construct and align on the bench, you need to do everything you can to save space and make your life easier. This unit intended for lab use, so its designed to be in the package that touts a head which is easily aim-able and manageable to use on an often crowed beam table.

Keep the nasty ugly hard-to-work-with psu box away from your optical system so that it is essentially not even a part of your system anymore. Believe me, the less you have going on that beam table the better. I'm currently working on LIBS projects - and this laser is preferable to my refrigerator-sized excimer laser box we have sitting on the table.

SirRej said:

This might be completely wrong, but shouldn't pointer sized air ionization be easy since the average output power is only 60mW. I've seen pointer sized systems capable of much higher outputs that 60mW, although they were in CW and not pulsed output.

Click to expand...

This unit is q-switched. This mode of operation collects energy in the lasing cavity for some time before releasing it all at once in the form of a very short pulse. When you release that much energy in such a short time period, the resulting peak power can easily be in the kW range.

If this kW power happens for even a nanosecond, you can focus that lovely 1.25M beam into a point and breakdown air. It is a very tiny spark shown in the video, though I suppose it still qualifies as "breakdown" in the air.

You cannot q-switch a handheld like this one is q-switched. It would be just another backpack full of charged lipos and HV coils. Think ghostbusters.

Thanks for all your clarification on this. You've done a good job explaining it to me (and slightly crushing my dreams of a handheld laser capable of creating air breakdown). I guess the only question left to ask would be: is a handheld laser capable of laser induced breakdown even possible? I hope so, because such a device would have a lot of really cool applications. I'm still a noob when it comes to the more advanced topics like q switching, frequency doubling, ect. That why I appreciate your replies.

this is flash photolysis ... you can't breakdown air with anything... if you mean dielectric breakdown that is made with electrons and unless you use plasmon laser it won't work never with normal super powerful laser because air would be turned to a plasma before so you don't breakdown the air// when you say ionize atoms is that you give energy to an electron band which is photoexcitation.. if you match electron band frequency and control hv you can make ionization happen, if you mean dissocation that is the correct word to use/../.. its the reverse of photon emission from the phosphor inside the laser hehehe.. now I need 402 nm laser I don't need much power.. who has one of these for a quick experiment? 401,73 nm is optimal.. then you can make ionization with multi-photon excitation.. and lower dielectric constant!