Page 53 - Lasers and IPLs in Medical/Aesthetic Applications v1.2
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Chapter 1 – Fundamentals of Medical/Aesthetic Lasers and IPLs v1.2
Pulse Duration
● Pulse duration is also known as “pulse width” or “pulse length” – they are all the same!
● Pulse duration is the length of time a pulse of light is ‘on’.
● Medical/cosmetic lasers can typically output pulse duration between 1 millisecond and a few minutes. There are exceptions – the Q-switched and picosecond classes of laser. These will be discussed below.
● Pulses can be generated in three main ways –
● continuous,
● single pulse and ● multi-pulse.
● A continuous pulse may last for seconds or minutes. Devices which generate continuous pulses are typically specific types of laser such as carbon dioxide, diode, argon and helium neon.
● These lasers output relatively low powers and are used for ablative processes such as epidermal removal, hair removal (diode lasers) and various low level therapies, which are best suited to very long pulses.
  This egg is under-cooked. Or, in laser terms, the pulse/heat duration was too short!
These eggs are cooked perfectly. The correct pulse/heat duration was used here....
Figure 26: Eggs and pulse durations
The choice of pulse duration is very important, depending on your target and what you are trying to achieve. It is, therefore, important to understand this parameter!
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Chapter 1 LEVEL A Fundamentals of Lasers/IPLs
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