LASER EMITTERS  used in Medical Lasers

The therapeutic result depends on the quality of the diagnosis and of the energy

delivered into the pathological tissue

The amount of energy is calculated with the average powers of all the laser emitters

There are different kinds of lasers

1. Helium Neon laser , with a 633nm continuouswave emission, with powers up to 60mW.

2. Semi-conductors lasers , with a wavelenght range from 630 nm to 980 nm
The powers range from few mW   to hundreds Watts, versus the process laser crystal wavelenght and emitter size.

The first AsGa lasers were only working in pulsed mode, with peak powers ranging up to few Watts.
The maximum frequency was 10 000 Hz with 200nS pulse width.

The main problem of these first devices, without optical power monitoring, was the important decreasing of the emitted

power versus the temperature of the laser emitter, then the programmed fluence, in joule/cm2, or in minutes, could not be

reached and the results were inconsistent.

The average power of these lasers is given by the following formula:

Paverage= Peak power x pulse Time x Frequency

For a peak power of 10 Watts and a frequency range from 10Hz ( pain relief) to 10 000 Hz
(anti-inflammatory effect), the average power ranges from:
10+4W x 200.10-9 s x (10 to 10000 ) Hz = 0.02 mW  to 20 mW .

This explanation makes understand some wrong results given by these old devices, coming from their low average power

for the treatment of pain, and emitting, in theory, a good average power only for the inflammation, but with the thermal

decreasing of the power during the treatment time, and a bad high frequency for pain relief.

3. Semi-conductor lasers with CW emission, of new generation, with optical power monitoring,
allowing it to emit a constant power WITH AN ADEQUATE COOLING, with the ability to be frequency modulated.

The power is also constant in this mode whatever the frequency, if used at the same duty factor.

VERY IMPORTANT:   For high powers, the laser is thermoelectrically cooled to increase its lifetime and maintain its

power constant during its lifetime; because it's the laser temperature which breaks it and power is going down and down

if it is not WELL cooled: nobody serious can give a warranty of result with a laser decreasind its power

All the biophoton high power lasers , from 250mW up to 30 Watts power,

are thermoelectrically cooled

For these technical reasons, these new laser emitters, with continuous powers up to hundreds Watts, increases the quality and

the repeatability of the results, ensuring the doctor to provide the same results for thousands hours lifetime of the laser device.

4. CO2 laser  is a gas laser emitting in the long infrared range at 10.6µm, with a 25 Watts power,
strongly absorbed by water, with effects as other athermic lasers, along with a thermal effect providing a quick effect

on pain relief on large areas in rheumatology and sports medicine .

biophoton 35 rue leon blum 31140 Saint Alban France tel:  33 5 61 70 34 55   fax: 33 5 61 70 35 65   info@biophoton.fr