https://en.wikipedia...-emitting_diode
Actually in this context what is commonly called "laser" is more likely to be a LED.
A LED is much cheaper, safer and better since light is emitted at an angle (usually 30°) instead than in a parallel beam like in a laser.
A laser needs to be aimed exactly on a specific small spot while a LED doesn't, a laser concentrate power which isn't a good thing when talking about therapeutic NIR light, only in trans cranial treatments a laser NIR light might be better since in order to cross the skull some power is needed and those treatments are sometimes to be quite spot specific.
A nostril NIR light device is trans cranial but nostrils are chosen in order to avoid the skull barrier therefore power isn't an issue and a wider light beam is preferred, of course, only part of the brain can be reached by such route but it seems to be a quite interesting part indeed which can be reached only that way.
A nostril device is nothing else than 2 NIR LEDs up the nostrils powered by a battery with a resistor in between (or the LED will die), total cost is few cents, I just bought one such devices for about 4$ including shipping only because case, battery connector and switch are worth it and will save me the work of assembling one.
I plan to replace the LEDs with NIR (near infrared) 850nm since it comes with 650nm ones which seems not to be optimal (closer to the red than to the infrared).
NIR LED light seems very interesting for several applications, skin aging reversal being just another one.
Beware of spending big money on NIR LED lights because it is extremely cheap and easy to build even a quite impressive one.
...and there is no way by complicated technical means to do better than just a LED light of appropriate power and wavelength, you are warned, no whistles and bells to add for marketing sake here.
Different LED colors at the same time seems to be worst than one wavelength at a time, not clear why yet.
Pulsating LEDs at frequencies don't seem to perform any better than still light.
More power isn't necessarily better, actually too much power is detrimental and can cause damage.
Powerful NIR light is desirable only for irradiating wide body areas at once, if not whole body, since what matters is power to surface ratio, yet hundreds of powerful NIR LEDs cost just few dollars at most.
