The Future of Light: IR & nIR in Full Spectrum Design

What We've Been Missing

For most of human history, artificial light was a reasonable approximation of the sun. Incandescent and filament lamps emitted a broad sweep of the spectrum — from visible light all the way through near-infrared (nIR) and infrared (IR) — closely matching the natural sunlight our biology evolved under. Then, around 2010, the widespread shift to LED lighting changed everything.

Yes, LED brought dramatic improvements in energy efficiency, and yes, the industry was right to move towards it. But in doing so, we stripped away something important. Standard LED sources are spectrally restricted to roughly 350–650 nm, with that well-documented blue peak around 420–450 nm, and virtually nothing above 700 nm. The longer wavelengths — the ones that sit beyond visible red and into the invisible spectrum — all but disappeared from our built environments.

This matters more than most people realise, and the science is beginning to catch up with what we've lost.

A landmark study published in January 2026 in Scientific Reports, led by Professor Glen Jeffery, demonstrated that supplementing standard LED lighting with broad spectrum light spanning 400–1,500 nm — including deep red and near-infrared — produced improvements in colour contrast sensitivity of up to 25%, with benefits persisting for up to two months after supplemental exposure ended. The finding was significant: blue-dominant LED suppresses mitochondrial respiration, while deep red and infrared wavelengths in the 670–900 nm range actively stimulate it — supporting ATP production, metabolic function, and visual performance.

Near-infrared light sits just beyond the visible red end of the spectrum, at wavelengths of approximately 700–1,400 nm. It is invisible to the eye, but far from inert. It penetrates beneath the surface of the skin and into underlying tissues, where it has been shown to reduce inflammation, improve circulation, stimulate collagen production, support muscle recovery, and drive cellular energy through mitochondrial activation — a process known as photobiomodulation (PBM).

The therapeutic window most supported by clinical evidence spans 630–900 nm, with specific wavelengths such as 810 nm and 850 nm among the most studied for anti-inflammatory and cognitive performance applications.

Why aren't we already integrating it? The honest answer is that we are beginning to, but the market has been slow to catch up with the science. The most significant advance has been the move from blue-pump to violet-chip LED platforms — producing a smooth, sunlight-like spectral power distribution with CRI ratings of 95–98. But none of these technologies, as yet, extend meaningfully into the near-infrared. The integration of nIR and IR within an architectural light source remains an emerging frontier.

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The Six Wavelengths That Actually Work

Despite the broad marketing language around 'full spectrum' and 'red light therapy,' peer-reviewed science is actually quite specific about which wavelengths produce measurable biological effects. The key enzyme here is cytochrome c oxidase (CCO) — the mitochondrial enzyme that absorbs photons and drives ATP production. It has two primary absorption windows: one in the red range, and one in the near-infrared.

There are six wavelengths that work.

Window 1: Red (620–680 nm)

630 nm — Used in multiple RCTs for skin rejuvenation. A 2025 trial reported measurable improvement in crow's-feet wrinkle scores over 16 weeks. Works best at the epidermal level for texture and tone.

660 nm — The most widely studied red wavelength in both clinical and consumer devices. Targets surface skin layers, upper dermal fibroblasts, and collagen signalling pathways, with a strong evidence base across hundreds of studies.

670 nm — Confirmed CCO photoacceptor wavelength, shown to restore cytochrome c oxidase function in cultured primary neurons. Also used in transcranial applications.

Window 2: Near-Infrared (760–900 nm)

810 nm — The peak absorption wavelength for CCO, and the single most studied wavelength in PBM research. Harvard Medical School dosimetry studies confirm higher tissue penetration and mitochondrial effect than longer nIR wavelengths.

830 nm — Causes measurable reduction of the CCO photoacceptor, confirming direct mitochondrial engagement. A histological study showed long-term increases in Type I and III collagen density up to 180 days post-treatment.

850 nm — Penetrates deeper than visible red, effective for subdermal fibroblasts, muscle, and connective tissue. A 2025 RCT reported significant improvement in skin wrinkle scores. Increasingly combined with 660 nm in dual-wavelength protocols.

To truly replicate natural light, the goal should be to deliver all six wavelengths. Within the built environment, that requires control — both to prevent overheating of the fitting, and to manage exposure so the body receives the right wavelengths at the optimal time of day.

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Power, Dose, and Getting It Right

Knowing the correct wavelengths is only part of the picture. Two further parameters determine whether a light source produces genuine biological benefit: irradiance (how intense the light is) and fluence (the total energy dose delivered).

Irradiance — Power Density (mW/cm²)

This is the strength of the light hitting the tissue at any given moment. The research consensus places the effective therapeutic range at 20–100 mW/cm² for most PBM applications. Below 20 mW/cm², sessions become impractically long. Above 100 mW/cm², the risk of entering an inhibitory range increases. For cosmetic and collagen-focused applications, 20–50 mW/cm² is the most widely cited effective range.

Fluence — Energy Dose (J/cm²)

This is the total energy delivered per unit area across a session, calculated as irradiance × time. The research consistently identifies three zones: below 2–3 J/cm² produces minimal cellular response; between 3–50 J/cm² the mitochondria respond optimally and collagen production is stimulated; above 60–80 J/cm² the biphasic dose response begins to suppress the effects being targeted.

For skin and collagen specifically, the most robustly supported target range is 4–10 J/cm² at the level of the target tissue.

The Biphasic Dose Response

Photobiomodulation follows the Arndt-Schulz law — a small stimulus excites biological activity, a moderate stimulus sustains it, a strong stimulus suppresses it, and an extreme stimulus can abolish it entirely. More is categorically not better.

A high-power consumer panel used at close range for 15 minutes can easily deliver 80–100 J/cm² to the face. That is five to ten times the optimal dose — well into the inhibitory range, and actively working against collagen stimulation rather than promoting it.

Dosage Reference

Application	Irradiance (mW/cm²)	Dose (J/cm²)	Duration	Best Wavelengths
Skin / Collagen (surface)	20–50	4–10	5–10 min	630, 660 nm
Dermis / Fibroblasts	30–100	10–20	10–15 min	660, 830, 850 nm
Deep Tissue / Muscle / Joints	50–100	20–50	15–20 min	810, 850 nm
Brain / Transcranial	10–50	3–10 at target	10–20 min	810, 1072 nm

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How Do We Deploy the Invisible in the Built Environment?

So, we have the correct wavelengths, the correct power output, and we understand the importance of dose. How do we deploy this within a residential or marine project?

Ideally, we want morning exposure — around 10 minutes upon waking — to trigger mitochondria and begin collagen production, and greater levels of red and nIR at least three hours before bed to avoid disrupting the natural onset of melatonin production.

The challenge is delivering this within an architectural context where discretion, design intent, and client comfort all have to be maintained simultaneously.

One common approach has been red light face masks, table lamps, and floor lamps. As a concept this is sound — controlled exposure without requiring architectural changes. The problem is the marketplace. It is, as with any popular wellness category, saturated with products that do not work.

We know this because we tested them. We purchased a range of red light devices and measured their spectral output, irradiance, and fluence. What we found was that the majority produced nothing more meaningful than holding a red-screened phone against your skin. No nIR, no IR — just red light from an LED no more powerful than a phone display. Not enough output, and the wrong technology.

There were exceptions. A small number of products were able to produce the correct values. What distinguished them was transparency — the manufacturers published wavelength data, power output, and in several cases full whitepapers and test reports. If a manufacturer cannot or will not tell you their wavelengths and power output, that tells you everything you need to know.

Our prediction: manufacturers will release full visible spectrum healthy light with nIR and IR available as a single unified source. The need for supplementary face masks or standalone therapy lamps will be removed entirely in projects where there is a proper lighting control system capable of delivering both visible and invisible spectrum from the same luminaire — timed via the control system for morning mitochondrial stimulation and evening melatonin support.

We are now working with this approach. It opens an entirely new paradigm for lighting design — one that moves beyond managing the timing of light, and into managing the completeness of it.

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Sources

Scientific Reports — LED Lighting & Visual Performance (Jan 2026, Jeffery et al.); PMC Review of Light Parameters & PBM Efficacy (2021); Biphasic Dose Response in LLLT — Hamblin et al.; Red Light Wellness Dosage Guide (2026); InHouse Wellness PBM Collagen Review (2026).