Page 42 - LASERS & IPLS IN MEDICAL/AESTHETIC APPLICATIONS

Chapter 1 – Fundamentals of Medical/Aesthetic Lasers and IPLs v1.1
Commonly Used Laser/IPL Terms
● There are a bunch of important laser terms and expression which you really should understand. These terms are used by laser users, engineers, operators etc all over the world. By understanding these expressions you will gain a deeper insight into how and why the laser treatments work. These terms are:
Wavelength
Energy & Energy Density (Fluence) Power & Power Density
Spot Size
Pulse Duration Repetition Rate
Here is a pdf describing these. Let’s look at these one by one:
Wavelength
● We discussed this earlier but it is so important we will quickly go through it again. You will hear about wavelength all the time when discussing lasers and IPLs. Wavelength is essentially the colour of the light and is expressed in nanometres (nm).
● Visible light ranges from around 380 nm, which appears as violet light, to around 780 nm, which is deep red light. The human eye is most sensitive to green light which is approximately around 555 nm.
● Wavelengths shorter than 380 nm are described as ultra-violet (UV). This region occupies around 180 nm to 380 nm.
● Longer wavelengths than 780 nm are known as infra-red (IR). However, the IR region is huge. It starts at around 780 nm but extends way up to 1,000,000 nm, which is a wavelength of 1 mm!
● Infra-red light is invisible but can be felt as heat. The region nearest the visible spectrum between 780 and 1400 nm is generally known as ‘near IR’, while the furthest regions from 3000 nm upwards is called the ‘far IR’.
● Most commonly-used skin lasers operate within the visible and near IR region with the exception of the carbon dioxide laser which has a wavelength of 10,600 nm.
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Chapter 1 LEVEL A Fundamentals of Lasers/IPLs
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