Lasers vs. LEDs: What is the difference?
Lasers have a coherent and collimated beam, and LEDs do not. The collimation is lost when the light hits the skin so this is not an advantage for a laser. In fact it can make it more dangerous to the eyes. Studies show that powerful LEDs have the same beneficial effect as lasers at a fraction of the price!
CLICK ON THE BOLD HEADINGS ON THE LEFT TO READ MORE ABOUT THE DIFFERENCE BETWEEN LASERS AND LEDS.
Lasers and LEDs In the area of physical therapy, two types of light sources are used. They are Laser Diodes (LD) and Light Emitting Diodes (LED). Usually, they are visible red (VR) or infrared (IR). Most of the popular diodes emit light in the 600–900-nanometer wavelength range. Lasers are monochromatic, thus emitting a single color of light. To the naked eye, LEDs also emit a single color; however, they actually emit over a narrow wavelength range of about 30 nm.
We are going to focus on using LEDs for many types of therapy. However, when we use the term “Light Therapy” we are not talking about “Bright Light Therapy.” Bright Light Therapy is a way to treat seasonal affective disorder (SAD) and certain other conditions by exposure to artificial light. SAD is a type of depression that occurs usually in the fall or winter and is more common in northern latitudes. Bright Light Therapy is used as a substitute for sunlight and has been shown to reduce the depressive effects from increased darkness during the winter months.
For many years, clinicians have used laser therapy for healing all types of injuries including sprains and strains, postoperative care, wound care, pain relief, and inflammation control. More recently, light-emitting diodes (LEDs) have become popular for many of the same applications because studies show that, for most applications, they are as effective and much less expensive than lasers.
Because the world is steadily using more LEDs for home lighting, automotive use, and in many types of health care and computer applications, the cost of LED diodes has dropped dramatically and the quality and power of LEDs has increased much faster than with laser diodes.
Laser diodes have both similarities and differences to LEDs in terms of construction. Both are produced from similar “sandwiches” of semiconductor materials to produce light.
There are differences between laser and LED light therapy, and each has its strengths and weaknesses. In general, if you want a lot of power in a small space or for surgery, you would choose to use a laser. However, when treating larger areas, LEDs are safer and much less expensive.
LASER, which stands for Light Amplification by Stimulated Emission of Radiation, is created when electrons become energized Clinical Procedures from an electrical current. They are then emitted as energized photons in a relatively narrow beam called coherent light.
In contrast, LEDs emit light in a broader range. This more divergent beam makes them potentially less harmful to the eyes and other sensitive areas. Still, they exert a similar effect on tissues as lasers.
A leading scientist in the area of light therapy, Dr. Tina Karu, says, “No significant difference was found for growth stimulation regardless of whether the light used was generated by a laser or from light of the same wavelength from a filtered incandescent lamp.”
In a NASA-sponsored study published in 2001, scientists found LED therapy to be effective for fast wound healing and pain reduction.
There are a number of opinions about which is better and there are clinicians who prefer one or the other.
Kendric Smith, a retired Professor Emeritus of Stanford University, said in 2005 that “all too often the laser phototherapy literature is written as if a laser is magical. Laser radiation follows (except for coherence) all of the same laws of physics and chemistry that the same wavelength of radiation from a conventional (non-coherent or LED) light source follows.”
Other more recent studies demonstrate the feasibility of using a LED lamp as an alternative to the laser source. The main characteristic is not the light coherence but achieving a certain concentration of light of the appropriate wavelength. Researchers have concluded that the efficacy was achieved satisfactorily by LEDs and had the added benefits of convenience, accessibility, and safety.
More LASER vs. LED Comparisson
Comparing the properties of Laser or at times commonly called LD for Laser Diodes, with, the more widely used LED that stand for Light Emitting Diode. Both of these light generating technologies have very distinct properties and characteristics on how they process to output their respective light beams.
Examining LD first, it produces or generates compacted or unified light coming from multiple diode sources which is called, known as or technically named as converged light output or LD sources grouped together to produce a light beam.
Focusing on LED now, it generates a high and diverged output or the output go different directed ways from a single source or a lone start point.
The greatest difference between the two is the method each uses to process or function in light generation.
While LED produces higher output due bigger bandwidths that are required, it produces very wide ranges of light that are less compact or concentrated.
The smaller output of LD fired light beam with minimal required bandwidth to produce, generates a very small beam or output that’s pinpoint small or tiny but in more concentrated and solid form.
Naturally, the LD devices which are more sophisticated have higher or expensive price tags but in the return of the investment they have higher level or just plain faster but with a higher degree of difficulty in its usage. The make of its device or technology is more complicated or it have a more complex structure and parts. With a more controlled lower output as it is designed for. Its state of the art output control can be switched to single or multi.
The sources of light for both LD and LED are Diodes, especially for the current day technologies and devices of LD.
The most effective Laser beam is colored green, speeding at 555 nanometers will make it completely visible up to 100%. Many small or hand held laser devices with green colored beams have pointers that produces an average of 532 to 555 nm light which is about 88 to 100% light generated.
| || || |
|FULL FORM||LIGHT EMITTING DIODE||AMPLIFICATION by RADIATION|
|DRIVING CURRENT||50 to 100 mA||5 to 40 mA|
|NATURE OF LIGHT||INCOHERENT, VARIOUS COLOURS||COHERENT, MONOCHROMATIC|
|MANUFACTURING JUNCTION AREA||WIDE||SMALL|
|BANDWIDTH||10 to 50 THz||1 MHz to 2 MHZ|
|POWER TO LIGHT CONVERSION EFFICIENCY||EST 20 %||EST 70 %|
|LIGHT NUMERICAL APERTURE||HIGHER||VERY LOW|
|COST||ECONOMICALLY LOW||HIGH FOR SPECIAL APPLICATION|
- Unlike other types of light therapy, LEDs do not contain ultraviolet rays. Therefore, they’re safe for regular use.
- LED light therapy doesn’t cause burns compared to other anti-aging treatments such as chemical peels, dermabrasion, and laser therapy. It may be safe for all skin colors and types.
- You shouldn’t use LED light therapy if you take Accutane for acne or if you’re experiencing skin rashes.
- Side effects are rare, but may include increased inflammation, redness, and rashes.
When used consistently, over time, LED lights are thought to penetrate your skin at different depths and cause various reactions in your skin, such as fighting acne-causing bacteria, plumping skin and reducing wrinkles.
Using varying LED wavelengths, this skincare technique purportedly helps treat acne, reduce inflammation and promote anti-aging effects.