THE SCIENCE OF LIGHT

THE SCIENCE OF LIGHT

A deeper understanding of light.

A deeper understanding of light.

Photobiomodulation uses selected wavelengths of red and near-infrared light. Research continues to investigate how wavelength and other light-delivery parameters influence the way light interacts with biological tissue.

Photobiomodulation uses selected wavelengths of red and near-infrared light. Research continues to investigate how wavelength and other light-delivery parameters influence the way light interacts with biological tissue.

EXPLORE THE SCIENCE

About the research

About the research

Research referenced on this page relates to red and near-infrared light and photobiomodulation generally. Studies may involve different devices, wavelengths, doses, and protocols from those used in Apexa products. References are provided for educational purposes and should not be interpreted as evidence that Apexa products will produce the same outcomes.

Research referenced on this page relates to red and near-infrared light and photobiomodulation generally. Studies may involve different devices, wavelengths, doses, and protocols from those used in Apexa products. References are provided for educational purposes and should not be interpreted as evidence that Apexa products will produce the same outcomes.

01 PHOTOBIOMODULATION

01 PHOTOBIOMODULATION

Light, understood differently.
Light, understood differently.

Photobiomodulation, commonly abbreviated as PBM, refers to the application of selected wavelengths of visible and near-infrared light under defined parameters.


Research in the field examines factors including wavelength, irradiance, exposure time, distance and total light energy.


Understanding PBM therefore requires more than looking at wavelength alone.

Photobiomodulation, commonly abbreviated as PBM, refers to the application of selected wavelengths of visible and near-infrared light under defined parameters.


Research in the field examines factors including wavelength, irradiance, exposure time, distance and total light energy.


Understanding PBM therefore requires more than looking at wavelength alone.

02 THE LIGHT SPECTRUM

02 THE LIGHT SPECTRUM

A broad spectrum.
A focused approach.
A broad spectrum.
A focused approach.

Light exists across a broad electromagnetic spectrum. Red and near-infrared light occupy different regions within that spectrum and have different optical characteristics.

Light exists across a broad electromagnetic spectrum. Red and near-infrared light occupy different regions within that spectrum and have different optical characteristics.

03 HOW LIGHT INTERACTS WITH BIOLOGY

03 HOW LIGHT INTERACTS WITH BIOLOGY

How light interacts with biology.
How light interacts with biology.

Research suggests that red and near-infrared light can be absorbed by endogenous cellular photoreceptors, including components associated with mitochondrial function. This interaction may influence cellular signaling involving ATP, reactive oxygen species and calcium, producing downstream biological responses.


The mechanisms of photobiomodulation remain an active area of research and may vary with wavelength, tissue and light-delivery parameters.

Research suggests that red and near-infrared light can be absorbed by endogenous cellular photoreceptors, including components associated with mitochondrial function. This interaction may influence cellular signaling involving ATP, reactive oxygen species and calcium, producing downstream biological responses.


The mechanisms of photobiomodulation remain an active area of research and may vary with wavelength, tissue and light-delivery parameters.

04 UNDERSTANDING WAVELENGTHS

04 UNDERSTANDING WAVELENGTHS

Different wavelengths.
Different optical characteristics.
Different wavelengths.
Different optical characteristics.

As light interacts with biological tissue, it may be absorbed, scattered or transmitted.

The extent of these interactions varies with wavelength and with the optical properties and composition of the tissue.¹

These wavelength-dependent characteristics are one reason different regions of the red and near-infrared spectrum are investigated in photobiomodulation research.²

As light interacts with biological tissue, it may be absorbed, scattered or transmitted.

The extent of these interactions varies with wavelength and with the optical properties and composition of the tissue.¹

These wavelength-dependent characteristics are one reason different regions of the red and near-infrared spectrum are investigated in photobiomodulation research.²

REFERENCES

1. Jacques SL. Optical properties of biological tissues: a review. Physics in Medicine & Biology. 2013;58(11):R37–R61. DOI: 10.1088/0031-9155/58/11/R37.
2. Mineroff J, et al. Photobiomodulation CME part I: Overview and mechanism of action. Journal of the American Academy of Dermatology. 2024.

05 THE APEXA SPECTRUM · RED + NEAR-INFRARED

05 THE APEXA SPECTRUM · RED + NEAR-INFRARED

The wavelengths at the center of Apexa.

Five wavelengths. One considered spectrum.
The wavelengths at the center of Apexa.

Five wavelengths.

One considered spectrum.

Apexa’s Light Series focuses on selected red and near-infrared wavelengths commonly represented in photobiomodulation research. Each device uses a wavelength configuration designed around its form factor, coverage, and intended use.


Apexa Core and Halo combine 630, 660, 810, 830, and 850 nm for broader red and near-infrared coverage.


Focused by design.
Apexa Flow uses 660 and 850 nm in a compact format designed for targeted use and portability.

Apexa’s Light Series focuses on selected red and near-infrared wavelengths commonly represented in photobiomodulation research. Each device uses a wavelength configuration designed around its form factor, coverage, and intended use.


Apexa Core and Halo combine 630, 660, 810, 830, and 850 nm for broader red and near-infrared coverage.


Focused by design.
Apexa Flow uses 660 and 850 nm in a compact format designed for targeted use and portability.

06 LIGHT DELIVERY MATTERS

06 LIGHT DELIVERY MATTERS

Wavelength is only part of the equation.
The wavelengths at the center of Apexa.

Five wavelengths.

One considered spectrum.

Irradiance describes the optical power delivered over a given area and is typically expressed in mW/cm².


Radiant exposure describes the amount of optical energy delivered over time and is typically expressed in J/cm².


Distance, exposure time, treatment area, beam distribution and tissue optical properties can all influence the light reaching the target.


For this reason, two devices emitting the same wavelengths should not automatically be assumed to deliver the same exposure.

Irradiance describes the optical power delivered over a given area and is typically expressed in mW/cm².


Radiant exposure describes the amount of optical energy delivered over time and is typically expressed in J/cm².


Distance, exposure time, treatment area, beam distribution and tissue optical properties can all influence the light reaching the target.


For this reason, two devices emitting the same wavelengths should not automatically be assumed to deliver the same exposure.

07 WHY THIS SPECTRUM

Selected with intent.

Apexa's goal is not to maximize wavelength count. The Light Series uses selected wavelengths across the red and near-infrared spectrum that are commonly represented in photobiomodulation research.


Core and Halo combine 630, 660, 810, 830 and 850 nm, while Flow uses a focused 660 + 850 nm configuration.


Wavelength selection is one component of light delivery. It should not be interpreted as evidence that one wavelength combination is universally superior to another.

08 WAVELENGTH COUNT VS EFFECTIVENESS

08 WAVELENGTH COUNT VS EFFECTIVENESS

Wavelength count alone does not establish effectiveness.
Wavelength count alone does not establish effectiveness.

The number of wavelengths emitted by a device does not, by itself, determine the effectiveness of a photobiomodulation protocol.


PBM studies vary across multiple parameters, including wavelength, irradiance, radiant exposure, exposure time, beam area, pulse characteristics and treatment protocol.¹–⁴


For that reason, evaluating a device solely by its number of wavelengths overlooks other important factors involved in light delivery.


More wavelengths do not automatically mean better photobiomodulation. What matters is the complete light-delivery protocol.

The number of wavelengths emitted by a device does not, by itself, determine the effectiveness of a photobiomodulation protocol.


PBM studies vary across multiple parameters, including wavelength, irradiance, radiant exposure, exposure time, beam area, pulse characteristics and treatment protocol.¹–⁴


For that reason, evaluating a device solely by its number of wavelengths overlooks other important factors involved in light delivery.


More wavelengths do not automatically mean better photobiomodulation. What matters is the complete light-delivery protocol.

REFERENCES

  1. Zein R, Selting W, Hamblin MR. Review of light parameters and photobiomodulation efficacy: dive into complexity. Journal of Biomedical Optics. 2018;23(12):120901. DOI: 10.1117/1.JBO.23.12.120901.

  2. Hadis MA, et al. The dark art of light measurement: accurate radiometry for low-level light therapy. Lasers in Medical Science. 2016. DOI: 10.1007/s10103-016-1914-y.

  3. Chung H, et al. The nuts and bolts of low-level laser (light) therapy. Annals of Biomedical Engineering. 2012;40(2):516–533. DOI: 10.1007/s10439-011-0454-7.

  4. Serrage H, Heiskanen V, Palin WM, et al. Under the spotlight: mechanisms of photobiomodulation concentrating on blue and green light. Photochemical & Photobiological Sciences. 2019;18(8):1877–1909. DOI: 10.1039/C9PP00089E.

09 WAVELENGTHS IN CONTEXT

09 WAVELENGTHS IN CONTEXT

A closer look at wavelengths used in light-based research.
A closer look at wavelengths used in light-based research.

The table below provides research context for selected wavelengths used in light-based research and devices, and explains why Apexa includes—or does not include—each within its current wavelength architecture.

The table below provides research context for selected wavelengths used in light-based research and devices, and explains why Apexa includes—or does not include—each within its current wavelength architecture.

Research context summarized from references 1–6. Wavelength selection alone does not establish product effectiveness; PBM outcomes depend on multiple light-delivery parameters.


REFERENCES

  1. Guo Z, Yuan K. The Application of Light Emitting Diode (LED) in Cosmetic Dermatology. Photodermatology, Photoimmunology & Photomedicine. 2025. DOI: 10.1111/phpp.70041.
    Supports blue (400–470 nm), yellow (570–590 nm), red (630–760 nm), and near-infrared (760–1200 nm) wavelength categories.

  2. Mineroff J, et al. Photobiomodulation CME part I: Overview and mechanism of action. Journal of the American Academy of Dermatology. 2024.
    Supports PBM use of red light roughly 620–700 nm and near-infrared roughly 700–1440 nm.

  3. Gupta A, et al. Noninvasive red and near-infrared wavelength-induced photobiomodulation: promoting impaired cutaneous wound healing. Photodermatology, Photoimmunology & Photomedicine. 2017. DOI: 10.1111/phpp.12282.
    Supports substantial PBM literature around 630–680 nm red and 800–830 nm near-infrared wavelengths.

  4. Nussbaum EL, et al. Photobiomodulation and diabetic foot and lower leg ulcer healing: A narrative synthesis. 2021.
    Reviews studies using 630–660 nm and infrared wavelengths including 850 nm.

  5. Grewal MK, et al. A Pilot Study Evaluating the Effects of 670 nm Photobiomodulation in Healthy Ageing and Age-Related Macular Degeneration. Journal of Clinical Medicine. 2020;9(4):1001. DOI: 10.3390/jcm9041001.
    Supports the statement that 670 nm is a legitimate studied red-light wavelength.

  6. Penberthy WT, Vorwaller CE. Utilization of the 1064 nm Wavelength in Photobiomodulation: A Systematic Review and Meta-Analysis. Journal of Lasers in Medical Sciences. 2021;12:e86. DOI: 10.34172/jlms.2021.86.
    Particularly useful for your 1060/1064 nm row because the review specifically examined 1064 nm high-powered laser PBM, which supports your point that this evidence comes from different light sources and protocols than Apexa’s LED architecture.

Research context summarized from references 1–6. Wavelength selection alone does not establish product effectiveness; PBM outcomes depend on multiple light-delivery parameters.


REFERENCES

  1. Guo Z, Yuan K. The Application of Light Emitting Diode (LED) in Cosmetic Dermatology. Photodermatology, Photoimmunology & Photomedicine. 2025. DOI: 10.1111/phpp.70041.
    Supports blue (400–470 nm), yellow (570–590 nm), red (630–760 nm), and near-infrared (760–1200 nm) wavelength categories.

  2. Mineroff J, et al. Photobiomodulation CME part I: Overview and mechanism of action. Journal of the American Academy of Dermatology. 2024.
    Supports PBM use of red light roughly 620–700 nm and near-infrared roughly 700–1440 nm.

  3. Gupta A, et al. Noninvasive red and near-infrared wavelength-induced photobiomodulation: promoting impaired cutaneous wound healing. Photodermatology, Photoimmunology & Photomedicine. 2017. DOI: 10.1111/phpp.12282.
    Supports substantial PBM literature around 630–680 nm red and 800–830 nm near-infrared wavelengths.

  4. Nussbaum EL, et al. Photobiomodulation and diabetic foot and lower leg ulcer healing: A narrative synthesis. 2021.
    Reviews studies using 630–660 nm and infrared wavelengths including 850 nm.

  5. Grewal MK, et al. A Pilot Study Evaluating the Effects of 670 nm Photobiomodulation in Healthy Ageing and Age-Related Macular Degeneration. Journal of Clinical Medicine. 2020;9(4):1001. DOI: 10.3390/jcm9041001.
    Supports the statement that 670 nm is a legitimate studied red-light wavelength.

  6. Penberthy WT, Vorwaller CE. Utilization of the 1064 nm Wavelength in Photobiomodulation: A Systematic Review and Meta-Analysis. Journal of Lasers in Medical Sciences. 2021;12:e86. DOI: 10.34172/jlms.2021.86.
    Particularly useful for your 1060/1064 nm row because the review specifically examined 1064 nm high-powered laser PBM, which supports your point that this evidence comes from different light sources and protocols than Apexa’s LED architecture.

GENERAL DISCLAIMER

GENERAL DISCLAIMER

Apexa products are designed for general wellness use. Information on this website is provided for educational purposes and is not intended as medical advice or as a substitute for advice from a qualified healthcare professional.

Apexa products are designed for general wellness use. Information on this website is provided for educational purposes and is not intended as medical advice or as a substitute for advice from a qualified healthcare professional.

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General Wellness Notice: APEXA products are intended for general wellness use and are designed to complement personal wellness, performance, and recovery routines. They are not intended to diagnose, treat, cure, prevent, or mitigate any disease, injury, or medical condition.


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