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Know About Laser Machines for Hair Removal

The introduction of laser technology as one of the permanent means of laser hair removal has led to introduction of a large number of laser equipments that have been designed for the user based on their skin types and the effect they desire. Fashion stores are flooded with a variety of laser equipments that can be used in hospitals, parlors and even at home.

Diode laser hair removal has surfaced as one of the most popular laser hair removal techniques. An 800-nm diode laser is found to be very effective for removal of dark, terminal hair. This laser operates at 800 nm, has pulse widths of 5-400 milliseconds, a 12 X 12-mm spot, a 2-Hz repetition rate and a cooling device. It is very safe for the darker skin types because of the longer wavelength, the active cooling, and the longer pulse widths. An extremely high-powered diode laser measuring about 3000 W has been approved for permanent hair reduction. Diode laser has been instrumental in providing permanent hair removal to almost 90 % of the people who have undergone treatment.

300-nm Ruby lasers are another type of unwanted hair removing laser equipment designed to be used on light skinned individuals with dark hairs. They operate in the conventional Q-switched mode for the treatment of tattoos and pigmented lesions and in the normal mode for hair removal. An integrated cooling device is used to cool the skin prior to laser pulse delivery to ensure proper effect. Studies have confirmed that a hair growth delay of 1- 3 months can be induced by treatment from ruby lasers. Additional studies with larger numbers of patients have confirmed that hair counts are reduced by approximately 30% after a single treatment with the ruby laser.

Alexandrite lasers measuring 755- nm are long pulsed and are being used for hair removal. As a result of greater penetration in depth added with a longer wavelength, the ratio of energy deposited in the dermis is greater as compared to epidermis of the skin. It results in reducing the risk for epidermal damage in persons with darker skin types. This equipment is best suited for removing unwanted hair in all skin types.

Hair removal is also carried out by Pulsed, non-coherent broadband light sources. By placing appropriate filters on the light source; wavelengths ranging from 590-1200 nm can be generated. To eliminate short wavelengths cut off filters are used. It ensures that only the longer, more deeply penetrating wavelengths are emitted. Pulse durations vary in the millisecond domain. A single or multiple pulse modes (2 to 5), with various pulse delay intervals, can be chosen. The wide choice of wavelengths, pulse durations, and delay intervals makes this device potentially effective for a wide range of skin types. The devices come with software that guides the operator in determining treatment parameters depending on the patient's skin type, hair color, and hair coarseness.

Recently, intense pulsed light systems have been developed that are combined with 1064-nm laser light. These devices should allow for treatment of a wide spectrum of hair and skin colors.

Removal of unwanted hair by laser technology is rapid, safe, and effective. Recent studies have confirmed the long-term efficacy of laser treatment. The procedure is also attractive because of its noninvasive nature, its ability to cover a large treatment area, and the speed of treatment. With adequate training and instruction, patients may administer self-treatments for hair removal with small, light-based unit in a safe and effective manner. Guidance of a physician may be required in the initial stages.

About the Author

The author is an expert in treating all kinds of hair loss problems. He also deals with male pattern baldness and alopecia areata.

Physics Question (10 Points)?

a) In a diode laser, electrons dropping from the conduction band, across the gap, and into the valence band produce the photons that add to the coherent light. The ZnTe laser has a band gap of 2.25 eV. Determine the wavelength of the light emitted.

a) The relation between photon wavelength and energy is E = hc/lambda, where h = Planck's constant, c = speed of light, lambda = wavelength

Just plug in the numbers. Since E is in eV, you can use h in eV units, which is 4.14 x 10^-15 eV-s

If c is in m/sec, the wavelength will be in meters.

b) i) Instead of E = hc/lambda, use E = hf. Just plug in the values of E and h.

ii) Now you can use f = c/lambda to solve for lambda

c) I would guess there is a formula in your notes that says "relationship between conductivity temperature" that is the key to this problem.

T-Ray Science, Inc. Grants Technology License to Toptica Photonics, Inc.
VANCOUVER, BRITISH COLUMBIA--(Marketwire - 04/29/10) - T-Ray Science, Inc. (TSX-V: THZ - News ) (T-Ray or the Company) an emerging leader in the field of TeraHertz (THz) research, is pleased to announce that it has granted a Licensing Agreement to Toptica Photonics, Inc. (Toptica). Toptica is a global market leader for THz sources and their applications, offering laser-based time and frequency ...

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