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Technical Laser Guide

Laser Wavelengths: Complete Guide & Treatment Selection 2025

Understand the science behind laser wavelengths in aesthetic treatments. Learn how different wavelengths affect skin, hair, and tissue for optimal treatment selection.

TL;DR

19 min read

Laser wavelength is the distance between wave peaks, measured in nanometers (nm), determining how laser light interacts with skin tissue. Different wavelengths penetrate to different depths and are absorbed by specific chromophores (melanin, hemoglobin, water), enabling selective targeting. Shorter wavelengths (694-755nm) have higher melanin absorption for light skin, while longer wavelengths (1064nm) penetrate deeper and are safer for darker skin tones. Understanding wavelength properties is essential for selecting the right laser for specific treatments and skin types.

Key Takeaways:

  • 1

    Wavelength determines laser color, penetration depth, and chromophore targeting

  • 2

    Shorter wavelengths (694-755nm) have higher melanin absorption, ideal for light skin and dark hair

  • 3

    Medium wavelengths (800-810nm) offer balanced absorption and penetration for most skin types

  • 4

    Longer wavelengths (1064nm) penetrate deeper with lower melanin absorption, safest for dark skin

  • 5

    Wavelength selection must match treatment goal (hair removal, vascular, skin resurfacing)

  • 6

    Proper wavelength choice is critical for safety and effectiveness in aesthetic treatments

What are Laser Wavelengths?

Laser wavelength is the distance between two consecutive peaks of a light wave, measured in nanometers (nm). It determines the color of the laser light and how it interacts with different tissues in the body.

Different wavelengths penetrate the skin to different depths and are absorbed by specific chromophores (light-absorbing molecules) like melanin, hemoglobin, and water. This selective absorption is the key to effective laser treatments.

Fundamental laser physics concept

Key Properties

  • Determines light color and energy
  • Controls tissue penetration depth
  • Targets specific chromophores
  • Affects treatment safety and efficacy
  • Determines skin type suitability

Laser Wavelength Spectrum

Understanding the electromagnetic spectrum and laser wavelengths used in aesthetic treatments

UV (200-400nm)
Not used in aesthetics
Visible (400-700nm)
Some aesthetic applications
Near IR (700-1400nm)
Most common aesthetic wavelengths - see how laser hair removal works
Mid IR (1400-3000nm)
Water absorption peak - used in CO2 laser resurfacing
Far IR (3000nm+)
CO2 laser range (10,600nm)

Common Aesthetic Wavelengths

The most frequently used laser wavelengths in aesthetic treatments

Ruby Laser (694nm)

Wavelength:694nm (Red)
Penetration:Shallow (1-2mm)
Target:Melanin
Best for:Light skin, dark hair
Applications:Hair removal, pigmentation

Alexandrite (755nm)

Wavelength:755nm (Near IR)
Penetration:Medium (2-3mm)
Target:Melanin
Best for:Light to olive skin
Applications:Hair removal, pigmentation

Diode (810nm)

Wavelength:810nm (Near IR)
Penetration:Deep (3-4mm)
Target:Melanin
Best for:Most skin types
Applications:Hair removal, skin tightening

Nd:YAG (1064nm)

Wavelength:1064nm (Near IR)
Penetration:Very Deep (4-6mm)
Target:Melanin, Hemoglobin
Best for:Dark skin tones
Applications:Hair removal, vascular lesions

KTP (532nm)

Wavelength:532nm (Green)
Penetration:Very Shallow (0.5-1mm)
Target:Hemoglobin, Melanin
Best for:Light skin tones
Applications:Vascular lesions, pigmentation

CO2 (10,600nm)

Wavelength:10,600nm (Far IR)
Penetration:Very Shallow (0.1mm)
Target:Water
Best for:All skin types
Applications:Skin resurfacing, cutting

Chromophore Absorption

How different wavelengths are absorbed by various chromophores in the skin

Melanin

400-800nm (Visible to Near IR)

Absorbs light in the visible and near-infrared spectrum. Higher absorption at shorter wavelengths.

Target: Hair follicles, pigmented lesions, tattoos

Hemoglobin

400-600nm (Visible)

Absorbs light in the visible spectrum, with peaks in the green and yellow range.

Target: Blood vessels, vascular lesions, rosacea

Water

1400nm+ (Mid to Far IR)

Absorbs light in the mid to far infrared spectrum, with peak absorption around 10,600nm.

Target: Skin resurfacing, cutting, ablation

Wavelength Selection Guide

How to choose the right wavelength for specific treatments and skin types

Hair Removal

Light skin, dark hair:Alexandrite (755nm)
Medium skin, dark hair:Diode (810nm)
Dark skin, dark hair:Nd:YAG (1064nm)
Light skin, light hair:Ruby (694nm)

Vascular Lesions

Small vessels, red lesions:KTP (532nm)
Large vessels, blue lesions:Nd:YAG (1064nm)
Rosacea, facial redness:KTP (532nm)
Spider veins, leg veins:Nd:YAG (1064nm)

Pigmentation

Light skin, dark spots:Ruby (694nm)
Medium skin, dark spots:Alexandrite (755nm)
Dark skin, dark spots:Nd:YAG (1064nm)
Tattoo removal:Q-switched lasers

Skin Resurfacing

Ablative resurfacing:CO2 (10,600nm)
Non-ablative resurfacing:Nd:YAG (1064nm)
Fractional resurfacing:CO2 (10,600nm)
Skin tightening:Diode (810nm)

Safety Considerations

Important safety factors when selecting laser wavelengths

Safety Factors

Skin Type Compatibility

Different wavelengths are safer for different skin types. Darker skin requires longer wavelengths to avoid burns.

Penetration Depth

Shorter wavelengths penetrate less deeply, reducing risk of damage to underlying structures.

Chromophore Targeting

Proper wavelength selection ensures energy is absorbed by target chromophores, not surrounding tissue.

Risk Factors

Incorrect Wavelength

Using the wrong wavelength can cause burns, scarring, or ineffective treatment.

Excessive Energy

Too much energy at any wavelength can cause tissue damage and adverse effects.

Poor Skin Assessment

Incorrect skin type assessment can lead to inappropriate wavelength selection.

About This Article

Expert Reviewed

This comprehensive guide was created by the Aesthetic.Energy editorial team in collaboration with AI-powered research and writing systems. Our content combines:

Expert Team

Medical professionals, aesthetic technology specialists, and industry experts review and validate all content for accuracy and clinical relevance.

AI-Assisted Research

Advanced AI systems analyze peer-reviewed research, manufacturer specifications, and clinical studies to synthesize comprehensive, up-to-date information.

Editorial Standards: All articles undergo rigorous fact-checking, source verification, and expert review to ensure scientific accuracy and clinical relevance. We cite authoritative sources including medical journals, FDA documentation, and manufacturer specifications.

Last updated: January 8, 2026

Have questions about this content? Contact our expert team or explore our research sources.

Frequently Asked Questions

What laser wavelength is best for hair removal?

The best laser wavelength for hair removal depends on skin type and hair color. Alexandrite (755nm) works best on light skin with dark hair. Diode (810nm) is versatile for most skin types. Nd:YAG (1064nm) is safest for darker skin types (IV-VI). The Fitzpatrick scale helps determine the appropriate wavelength.

How do different laser wavelengths affect skin penetration?

Longer laser wavelengths penetrate deeper into the skin. Near-infrared wavelengths (755nm, 810nm, 1064nm) penetrate 1-4mm into the dermis, targeting hair follicles and blood vessels. Mid-infrared wavelengths (10600nm CO2) have very shallow penetration (0.1mm) and are used for surface treatments like skin resurfacing.

What is selective photothermolysis?

Selective photothermolysis is the principle that specific wavelengths of light can target specific chromophores (melanin, hemoglobin, water) while sparing surrounding tissue. This allows precise treatment of hair follicles, blood vessels, or skin layers without damaging adjacent structures. Learn more about laser physics.

Can the same laser device use multiple wavelengths?

Some advanced laser systems can use multiple wavelengths, but most devices are optimized for a specific wavelength. Multi-wavelength systems offer versatility but may sacrifice power and precision. Single-wavelength systems provide optimal performance for their specific application.

How do I choose the right laser wavelength for my practice?

Choose laser wavelength based on your patient demographics, treatment goals, and skin types you typically treat. Consider the Fitzpatrick scale distribution of your patient base. For diverse skin types, Nd:YAG (1064nm) offers the broadest safety profile. For light skin with dark hair, Alexandrite (755nm) or Diode (810nm) may be more effective.

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