Laser hair removal offers an effective means of eliminating unwanted hair without shaving and waxing, thus eliminating their associated problems, such as ingrown hairs and razor bumps.
Laser energy is absorbed by melanin pigments found within hair follicles to facilitate selective photothermolysis – the basis of laser hair removal technology.
Pulse Duration
Laser hair removal works via selective photothermolysis, matching specific wavelengths of light with specific tissues for destruction of their follicles. Melanin absorbs energy from laser beams and converts it to heat; to successfully destroy follicles, sufficient heat must be generated while avoiding burns or scarring from excess energy loss – these goals can be accomplished using pulse duration, spot size and fluence controls controlled by an operator.
Pulse duration, or pulse width, refers to the length of time a laser delivers energy. An ideal duration should keep melanin absorbing and discarding heat without harming follicles, while too short of a pulse could fail to deliver sufficient heat and lead to thermal injury of skin.
Pulse duration options vary based on the type and coloration of hair to be removed, as well as skin pigmentation. Fine hairs need shorter pulses while thicker ones can tolerate longer ones. Spot size also plays an integral part in how deep into skin it penetrates; larger spots enable operators to treat larger areas while smaller spots provide greater precision with energy application.
Fluence measures the energy consumed per treatment session, measured in joules per square centimeter. A higher fluence will speed up follicle destruction and lead to more permanent hair reduction; however, high fluences can also result in side effects like pigment changes, blistering and skin sensitivity.
Researchers have conducted numerous studies to ascertain the optimal spot size and fluence for laser hair removal, but few studies have focused on exploring the impact of pulse duration variations on results and side effects. This research sought to test 755nm alexandrite laser hair removal with various pulse durations in female patients suffering from facial hirsutism who fall under Fitzpatrick skin types II-IV.
Pulse Width
Laser hair removal works through selective photothermolysis, where light energy damages the epidermis and surrounding tissue of one specific hair follicle to disable its ability to produce more hair. Determining an optimal energy level that will cause enough damage without harming adjacent skin can be challenging; various variables must be considered including hair color, size, density and pulse width as a measure of success of treatment.
One way of assessing whether or not a pulse width is suitable is to look for signs of follicular edema – temporary swelling around the base of a hair follicle that indicates laser is reaching deep dermis in order to destroy follicles. Pulse repetition rate measures how quickly laser emits laser energy; too high of an energy output may damage surrounding tissues and produce painful results.
Selecting a pulse duration that exceeds thermal relaxation time of the target tissue can help focus the laser energy exclusively on chromophore pigments, thus limiting side effects. However, too long of a duration could allow other pigments in skin cells to absorb some of that laser energy instead.
Researchers have conducted extensive studies on the efficacy of short pulse durations for hair removal. These short pulses allow higher fluence levels to be used on patients with darker Fitzpatrick skin tones without damaging the epidermis; allowing laser light energy to directly heat inner and outer root sheaths as well as germinative zones of hair follicles without disrupting melanosomes that absorb light energy in the epidermis.
Diode lasers with adjustable pulse durations are essential to delivering optimal treatment outcomes across all patients, regardless of skin color or hair thickness. Unlike ruby lasers, semiconductor laser diodes can be manufactured for any wavelength in their therapeutic window; this allows energy delivery at precisely the right moment to the target tissue. When combined with adjustable spot sizes, pulse rates, and fluences a skilled laser technician can deliver far superior treatment outcomes regardless of skin color or hair thickness.
Pulse Height
Laser hair removal devices emit short bursts of energy called pulses onto the skin surface. These pulses target hair follicle roots and bulbs for destruction by emitting heat generated from these pulses; heat generated prevents future hair growth as a permanent solution to unwanted body hair. However, results do not come instantaneously; patients must undergo multiple sessions to see lasting effects. It is also crucial that patients select an ideal device tailored specifically to their own skin type and tone as it needs to be customized according to absorption spectrum as well as variable spot size and pulse duration capabilities for best results.
The duration and width of each laser pulse determine how much heat is delivered to its target area. Pulses should be short enough to avoid thermal injury to the epidermis while long enough to produce sufficient heating at and around chromophore of hair follicle. Thinner hairs typically require shorter pulse lengths that easily direct heat onto their epidermis for safe removal; thicker ones require longer pulse lengths to sustain sufficient heating needed for destruction.
As such, an ideal laser hair removal device must allow users to customize its pulse height according to skin tone and hair color – this way it can deliver just enough energy to disintegrate follicles without harming surrounding tissue.
There are many diode lasers designed specifically to remove hair, each offering various wavelengths and pulse durations to suit different skin types and tones. Furthermore, some offer multiple wavelengths allowing more accurate customization based on individual skin tones and types.
Laser hair removal devices that employ 755nm alexandrite wavelength with variable pulse durations and spot sizes are currently the gold standard in hair removal technology. A split face, evaluator-blind trial conducted to compare two laser options–long pulse versus short pulse Nd:YAG lasers–was conducted and both groups achieved statistically significant reductions in density and thickness after six sessions of treatment.
Pulse Angle
Laser hair removal treatments use light pulses to destroy hair follicles and stop future growth of the hair, offering FDA-approved permanent hair reduction. Most people achieve silky smooth skin that lasts long-term; individual results may vary and you’ll require multiple treatment sessions before your desired result can be reached. Your technician will help select an appropriate laser device that suits both your skin tone and specific needs while creating an affordable cost estimate that stays within budget.
Apart from pulse width, laser energy emitted at different frequencies is also an integral component in selecting an effective treatment option for your unique skin type. High repetition rates may lead to buildups of thermal energy which damage nearby tissue leading to side effects like redness, swelling and blistering; hence it’s wiser to opt for low repetition rates while employing cooling techniques during your sessions.
One important element in the success of laser hair removal treatments is selecting a wavelength for energy absorption. Short wavelengths tend to be less selective of melanin in skin and hair and increase post-inflammatory hyperpigmentation risks; long wavelengths, however, tend to be more specific for melanin and penetrate deeper to further decrease risks of epidermal damage.
Pulse duration is also important as it determines how quickly laser energy reaches its intended tissue. Longer pulse durations (over 10 milliseconds) allow time for cooling of the epidermis before applying additional energy, helping prevent unwanted side effects like hypopigmentation and erythema from developing, while pulses shorter than 10 ms could damage follicles leading to ineffective treatments.
Combining these factors together will determine the success of laser hair removal treatment. Selecting an appropriate laser device suited for your skin type, customizing pulse length and frequency settings accordingly, as well as taking measures prior to and post treatment are all key elements in creating safe, effective, long-term hair reduction.
