Safe Laser patent - Károly Rózsa doctor of Hungarian Academy of Sciences

Safety Classification of Safe Laser

The classification of the laser device was made according to the standard MSZ EN 60825-1 ‘Safety of Laser Products’. We have applied the requirements with regard to the diffusion for the classification.

The Safe Laser lamp has a new, patented, special laser light source which emits polarised, coherent and monochromatic light like other lasers, but in contrast with conventional lasers, its light is (no parallel rays) and cannot be focused optically into a pointed light. This new technology is known as ‘Safe Laser Light’ (SLL). (Patent registration number: 2103448)

Measurements and Classification by:
Wigner Research Centre for Physics Optical Laboratory (former Central Research Institute for Physics – Research Institute for Solid State Physics)

Test Procedure
The measurement was made according to the measuring instructions set out in the MSZ EN 60825-1 standard, which prescribes the following steps:

We measured the luminous flux emerging from behind the diaphragm of 3.5 mm in diameter set at a distance of 1 m from the diaphragm of 7 mm in diameter set at a distance of 35 mm from the diffusing lens. As a result, we obtained the performance of 4×10^-4 W, by which we graded the equipment in class 2. During the development of ‘Safe Laser Light’, beyond the measurements set out by the standards, we have also examined what power density can be achieved with a convergent lens in the eye. Based on our measurements, the power density of ‘Safe Laser Light’ is 2500 times less than a parallel laser beam of the same performance, therefore it can be used more safely.

Technical Data of Device

• Maximum performance of the light source: 150 mW
• Light emerging from the light source: scattered radiation
• Wave length: 660 nm (red)

Safety Standards for Lasers in Class 2:

Radiation emitted from the laser equipment poses no danger to the eyes, because the involuntary blink reflex of the eyes (the reaction time of which is 0.25 s) provides enough protection against it. There is no need for protective device (such as goggles) if an optical device (such as convergent lens) is not inserted.

Dr. Károly Rózsa, Hungarian Academy of Sciences:

‘Professor Endre Mester discovered in the second half of the 1960’s that the previously non-healing wounds (these were mainly leg ulcers and pressure ulcers) could be healed thanks to the impact of low-intensity helium-neon laser light. At that time, besides my laser studies, I was of assistance to Professor Mester, who needed my specific knowledge of the physical properties of light.

The light of gas lasers used in medicine has a number of specific characteristic that differ from the light of conventional light sources. The bandwidth of this light is very low (single-colour), it is linearly polarised, and its wave nature is much more unambiguous than that of conventional light sources.’ Of course, physicists immediately raised the question which property of laser light caused the healing of wounds, because such healing effect has not been experienced in case of wounds exposed to sunlight. As yet, there is no clear answer to this question: probably several effects help the healing of wounds.

The Discovery of Polarised Light

The question whether the effect is due to the polarised light of lasers came naturally to our minds. Under medical supervision, we managed to heal the non-healing leg ulcer of one of my friends with a tweaked slide projector, in which we preserved and also polarised the broadband red light. Based on this result extensive examinations were immediately started, and the use of polarised light lamps (Evolight, Bioptron, Infrapol, etc.) became a widespread practice. I’m a co-inventor of the patent on this method. Many patients got better thanks to the use of polarised light lamps.

The popularity of these lamps is also due to the fact that gas lasers were very expensive and of a very limited availability. It is not yet known to what extent the medicinal properties of these lamps are equivalent to those of lasers. However, it is a fact that in a number of cases when polarised light lamps did not help we have managed to achieve great results with laser.

Cheap Lasers: a New Dimension

In the nearly 40 years since then, as a result of the development of solid-state physics, the semiconductor lasers (diode laser) have appeared, which are cheaper, much more powerful and much simpler than helium-neon laser. These lasers proved to be very effective in medicine and superseded the early gas lasers, though they are nowhere near as single-colour as gas lasers, their light is not always polarised and its wave nature is not as much emphasised. At the same time the non-laser semiconductor light sources (LED) – which also have healing properties – have appeared in medicine. The fact that the semiconductor light sources are so effective raises a number of further interesting question which I have been investigating ever since besides my research in the field of plasma physics.

Dr. Károly Rózsa, Hungarian Academy of Sciences:

‘Professor Endre Mester discovered in the second half of the 1960’s that the previously non-healing wounds (these were mainly leg ulcers and pressure ulcers) could be healed thanks to the impact of low-intensity helium-neon laser light. At that time, besides my laser studies, I was of assistance to Professor Mester, who needed my specific knowledge of the physical properties of light.

The light of gas lasers used in medicine has a number of specific characteristic that differ from the light of conventional light sources. The bandwidth of this light is very low (single-colour), it is linearly polarised, and its wave nature is much more unambiguous than that of conventional light sources.’ Of course, physicists immediately raised the question which property of laser light caused the healing of wounds, because such healing effect has not been experienced in case of wounds exposed to sunlight. As yet, there is no clear answer to this question: probably several effects help the healing of wounds.

The Discovery of Polarised Light

The question whether the effect is due to the polarised light of lasers came naturally to our minds. Under medical supervision, we managed to heal the non-healing leg ulcer of one of my friends with a tweaked slide projector, in which we preserved and also polarised the broadband red light. Based on this result extensive examinations were immediately started, and the use of polarised light lamps (Evolight, Bioptron, Infrapol, etc.) became a widespread practice. I’m a co-inventor of the patent on this method. Many patients got better thanks to the use of polarised light lamps.

The popularity of these lamps is also due to the fact that gas lasers were very expensive and of a very limited availability. It is not yet known to what extent the medicinal properties of these lamps are equivalent to those of lasers. However, it is a fact that in a number of cases when polarised light lamps did not help we have managed to achieve great results with laser.

Cheap Lasers: a New Dimension

In the nearly 40 years since then, as a result of the development of solid-state physics, the semiconductor lasers (diode laser) have appeared, which are cheaper, much more powerful and much simpler than helium-neon laser. These lasers proved to be very effective in medicine and superseded the early gas lasers, though they are nowhere near as single-colour as gas lasers, their light is not always polarised and its wave nature is not as much emphasised. At the same time the non-laser semiconductor light sources (LED) – which also have healing properties – have appeared in medicine. The fact that the semiconductor light sources are so effective raises a number of further interesting question which I have been investigating ever since besides my research in the field of plasma physics.