Wavelengths of Lipo Laser Machines
If you remember your basic science, you would easily understand that higher wavelength is equivalent to lesser energy. The lower the wavelength, the higher is the energy of the laser. Wavelength is measured in nano-meters (nm in short). So, for your basic understanding, 650 nm wavelength is much stronger (more powerful) compared to say 1440 nm.
With this understanding, let us get started. The objective of using a lipo laser or LED lipo is to melt your body fats. The more effectively the body fats dissolve, the more effective your session becomes. At the same time, there is another serious point to consider: you cannot expose your body to arbitrarily high energy levels and thereby cause undesirable side-effects.
So the key question is, what is a low enough wavelength that is strong enough but safe enough?
The moment I mention "safety", I am sure you understand how critical it is to protect yourself from exposure to harmful radiation. That essentially translates to getting a laser (either your own or at your clinic) with a good quality certification. These laser machines radiate up till the infrared range (less than 700 nm wavelength, such as the 635, 650 and 670 nm ranges).
And this opens up another question - do the longer wavelength lasers end up going deeper into the skin, simply because each wave is longer? There is a school of thought that believe this, and produces machines accordingly. Smart Lipo, for example, produces their newest Triplex machine with wavelengths of 1064 nm, 1320 nm and 1440 nm.
The modern machines
However, most of the modern laser / LED machines are in the 600 nm ranges, as that range is believed to be the most effective by most of the practitioners. And the fact that low-wavelength laser (and any electro-magnetic wave of low wavelength) will be richer in energy levels has been proven since before the times of Einstein. This is why, the modern machines aim to go as low in the wavelength as they can, without compromising on the safety standards.
The first generation of lipo laser machines have a base wavelength of around 670 nm, the second generationn around 650 nm and the third generation has around 635 nm. Of course, the wattage of the third generation are higher compared to the two older generations, but the slight additional cost is worth the huge return that the end-users get from these. Further note that, the higher the wavelength the machine has, the lower would be the frequency. Low frequency corresponds to low energy (and high wavelength). Lower frequency (higher wavelength) has a detoxification and lymph drainage effect on the human body.
Another point to note is that the lasers/LEDs are aiming to move to have more diodes (or, more diodes per paddle to increase diode density) with lower wattage but the same wavelength. There are recent research studies expressing belief that given everything else the same, a higher fluence (higher number of diodes) helps faster and better effect on the body. Brands using 3rd generation lipo laser technology are moving in this direction today. Zerona, for example, has adapted the use of high fluence low level laser therapy, over an array of 15 milliwatt diodes of 635 nm wavelength each.