Definition: Laser hair removal is the use of laser energy to produce long-term hair reduction.
With new technologies rapidly emerging, tedious or painful removal methods such as shaving or electrolysis can now be left behind.
How it Works
A laser is a device that produces light of a single color, or wavelength. Lasers used in dermatology emit pulses of high-energy light that are taken up, or absorbed, by the desired target. This is called Photoepilation.
Photoepilation destroys the hair follicle using controlled flashes of light. The hair absorbs the light projected by the device and the intense heat destroys it. In order to obtain the best results with photoepilation, we need all the light energy sent by the machine to be absorbed by the hair and not by the nearby tissues. Different wavelengths are used for different targets. 
In the case of hair removal, the target is the melanin pigment contained within the hair shaft. The heat from the light of the laser is absorbed by the pigment, or melanin, in the hair. That heat then triggers inflammation in the hair follicle, which causes the follicle to go into its resting (telogen) phase. While resting, the follicle produces no hair. 
Who is a good Candidate?
The best candidate for laser hair removal would be someone with very light skin and dark hair. That's because we want the laser to "see" the hair without "seeing" the skin because we want the hair, not the skin, to absorb the laser light. Having said that, basically anyone who has some pigmentation to their hair is a good candidate for laser hair removal.
A BAD candidate for laser hair removal would be people with white or blonde hair, or people with hair between or around the eyes such as a "unibrow". 
Types of Lasers
For laser hair removal there are really three types of lasers that we use today, the Alexandrite laser, the Diode laser and the Nd:YAG laser. In the early days of laser hair removal the ruby laser was one of the first lasers that was ever produced, that had the shortest wavelength of all, at 694nm. The Alexandrite laser emits light at 755nm, the diode laser emits light at 810nm, and the Nd:YAG has the longest wavelength at 1064nm.
Having someone with different lasers who is highly experienced is a must if you have darker skin. Darker skin patients often need to be treated with a special laser such as the Nd:YAG laser because that laser can "see" the skin less, but still see the hair. 
Advantages to Laser Hair Removal
Laser hair removal is a non-invasive method of photoepilation, which does not require needles or chemical creams. The advantages of laser hair removal include:
Disadvantages of Laser Hair Removal
Although laser hair removal is an excellent treatment option, some patients may experience hair regrowth. However, this hair is usually finer and lighter in color. Possible side effects, though very rare, may include damage to the surrounding healthy tissue in the form of scars, burns, redness and swelling. The process is also not as effective on unpigmented (gray) hairs and red or blonde hair. 
What Happens During Treatment?
During the procedure, laser light will be delivered through a hand held piece attached to a laser console. You may experience a stinging sensation as the laser pulse is delivered. To reduce discomfort, a cooling system may automatically remove heat from the surface of your skin before, during and after the laser exposure. You should not need general anesthesia or pain medication, but a topical anesthetic cream may be applied to sensitive areas. The process can take from just a few minutes for an upper lip to several hours for a full back and legs.
Laser treatment itself may cause a slight tingling sensation. Most patients tolerate the procedure well. But because some areas of the body are more sensitive than others, topical anesthesia can be an option. The appearance of the treated area immediately after the laser session will vary from patient to patient depending on the extent of treatment and skin type. Immediate after-effects, if any, are minor. They may include redness and swelling, which disappear in a short time. Most people return to normal activity right away.
During the procedure, you wear goggles to protect your eyes from accidental exposure to laser light. The procedure causes a slight charring of your stubble. You may notice a strong odor of singed hair, which is normal. 
How Many Treatments?
Most people benefit from a series of three to seven treatments, spaced at four- to eight-week intervals. After the initial series of treatments, the hair in a given area is usually reduced in both amount and thickness for a very long period of time. However, it may not be completely gone. To keep an area completely devoid of hair, maintenance treatments are almost always required. Fortunately, maintenance treatments can usually be administered at ever-increasing intervals. Eventually, they may be needed only once a year, or even less often. How frequently you'll need to return for treatments will depend on the area of your body being treated as well as on certain charactistics about your hair. Everybody is different. 
How to Choose Where to Have Laser Hair Removal
Before opting for a treatment, it is always a good idea to research the qualifications of the Medical Director of the facility. Is he or she Board Certified in Dermatology? Is there a physician present in the office? Are all personnel performing the procedure licensed doctors or registered nurses? Is the atmosphere professional? Since this is a medical procedure, it should be selected with the same care you give while selecting a doctor or a surgeon. 
Please make sure that your doctor is: