A near infrared light wavelength printed on a product page is usually a nominal specification, not a complete description of its emission. To understand an LED spectrum, look for the wavelength axis, the vertical-axis units, the peak and spectral width, then read the measurement conditions. A curve's shape and a headline number answer different questions.
This guide uses a real public LED component datasheet as a worked example. The component is not identified as a part used in any VanqHeal product. Its curve helps explain how to read technical information; it cannot establish a consumer device's output, safety classification or skin results.
First Identify What Was Measured
Before reading the graph, find the product or component name and document version. A semiconductor emitter, a complete panel and a mask measured with its eye accessories are different test objects. A report for one does not automatically describe the others, even when they share a nominal wavelength.
Check whether the graph represents a typical component, one measured sample or a specification limit. Typical behaviour describes an example under stated conditions. It is not necessarily a guaranteed value for every component, much less every assembled device containing similar emitters.
Ask what surrounds the source. Lenses, covers, diffusers and operating electronics can affect the assembled system. A component datasheet may be relevant to design, while a measurement of the final device is needed to describe that device under its own operating conditions.
Also separate measurement from illustration. A smooth curve drawn for a marketing explanation can be useful conceptually, but it needs a clear label. Do not treat an attractive diagram as measured data unless its source and conditions actually establish that status.
Read the Axes Before the Peak
The horizontal axis usually shows wavelength. Check the units: nanometres and micrometres differ by a factor of 1,000. A graph ending at 950 nm shows a different window from one extending through several micrometres. An apparently missing band may simply lie outside the displayed range.
The vertical axis tells you what the curve can support. Relative intensity, often scaled to 100% at its maximum, shows the distribution's shape. It does not reveal the absolute optical output. Two emitters with very different outputs can both produce a relative curve reaching 100%.
Absolute spectral measurements need units and a description of the measured quantity. A plot of spectral irradiance at a stated surface differs from total radiant flux or a detector signal. Do not convert between them merely because the curves look similar. Geometry and measurement definitions matter.
Watch for a logarithmic scale. Equal vertical steps on a logarithmic axis represent ratios rather than equal numerical increments. A low tail can look more prominent than on a linear plot. Read tick labels before comparing the apparent width or relative strength of two bands.
A Real Example: Peak, Centroid and Width
The public LED component datasheet, version 1.16 dated 10 June 2026, lists typical values under specified component conditions: 1,000 mA, a 10 ms pulse and 25°C ambient temperature. It gives a peak wavelength of 860 nm, a centroid wavelength of 850 nm and a full width at half maximum of 30 nm. Its relative spectral-emission graph appears.
This is a component example, not a measured VanqHeal spectrum. The different peak and centroid values are useful: a single 850 nm label does not necessarily identify the tallest point of a curve.
The peak is where the plotted emission reaches its maximum. The centroid summarises the distribution by weighting wavelength across the emission. For an asymmetric curve, the two need not coincide. Read the named parameter rather than deciding that two different values are a contradiction.
Full width at half maximum, abbreviated FWHM, describes the width between the two points where the curve reaches half its maximum. It is a width, not another peak. A stated 30 nm FWHM does not mean that emission stops abruptly 15 nm on either side of the centroid. The curve can have tails beyond its half-height crossings.
Follow the Curve Without Inventing Precision
Start at the peak, then trace both sides towards lower relative intensity. Notice whether the curve is symmetrical, has a shoulder or falls away more slowly on one side. Those features explain why a label cannot capture the whole distribution.
Use the graph's resolution honestly. If a PDF provides a plotted line but no raw numerical data, you can describe its shape and read clearly marked values. You should not report several decimal places extracted from a small image. Enlarging the picture does not create measurement precision that the source did not publish.
The component example has a relative curve and separately tabulated parameters. Use the table for its stated values; use the graph to understand their relationship. Do not redraw it as a guessed Gaussian curve and present the result as the manufacturer's measurement.
If you need to calculate an area under a spectrum or a weighted exposure, ask for the underlying data and method. A screenshot can help identify what to request, but it is a weak basis for a quantitative calculation. Missing numerical data should remain missing rather than being replaced with a visually plausible curve.
What Multiple Peaks Can Mean
A device combining visible red and near-infrared emitters may show separate bands when both operate. Other multi-colour modes can add further bands. The number of peaks depends on the active emitters and the measurement, not simply the number of colour names printed on a controller.
A mixed-mode curve should identify the setting used. If red and near-infrared were measured together, that does not establish the output of near-infrared alone. Ask whether the relative heights represent a shared absolute scale or separately normalised curves. Separate normalisation can conceal large differences in actual output.
Imagine two charts placed side by side, each with a maximum of 100%. One shows a red channel and the other a near-infrared channel. You can compare the locations and shapes of the bands. You cannot conclude that the channels emit equal optical power from those two maxima.
Similarly, a panel's electrical wattage does not fill that gap. Electrical input, losses and optical output are different quantities. A spectrum and a wattage label are useful documents, but neither should be stretched into a delivered dose without the required measurements.
Conditions That Belong Beside the Graph
Read current, pulse duration or continuous operation, temperature and the test arrangement. An emitter measured under a short pulse is not automatically characterised for an extended consumer session. The source must state what the data actually represent.
For an assembled device, look for the selected mode, power level, supply condition and any accessories present. If a report includes an optical measurement at a surface, check the distance, orientation, sampled area and instrument method. These details determine what another measurement would need to reproduce.
| Document field | Why it matters when comparing spectra |
|---|---|
| Product or component name and document date | Establishes which component or device the document describes |
| Peak or centroid label | Prevents different wavelength parameters from being confused |
| Vertical-axis units and normalisation | Shows whether the curve describes shape or absolute output |
| Mode and operating conditions | Establishes which emitters and settings were active |
| Measurement geometry | Limits claims about where a reported exposure applies |
| Raw data and uncertainty, if available | Determines which numerical comparisons can be supported |
No single field proves a skin outcome. The purpose of this checklist is to read a measurement correctly, then decide whether it answers the specification question you actually have.
Check the Wavelengths of the Model You’re Considering
VanqHeal's 5-Colour Panel page inspected on 12 October 2026 lists nominal wavelengths of 630, 460, 590, 605 and 850 nm. Those listing values are not a measured spectrum of the assembled panel. The component example above is not evidence that this panel contains that component or shares its peak and width.
Ask which exact model and controller the listing describes, which mode activates the 850 nm channel and whether a corresponding finished-device spectrum is available. Request its date, operating setting, axis units and measurement conditions. If only nominal LED values are available, keep that distinction visible in your comparison.
Ask About This Model’s Wavelengths. You can also examine the 5-Colour Panel listing while preparing model-specific questions. A useful reply should connect the document to the product, rather than supplying an unrelated curve with a similar headline wavelength.
Read the spectrum as a description of emitted radiation under stated conditions. It is one part of device assessment, alongside operating instructions and evidence for the intended use. Keeping those documents separate makes each one more informative.
Frequently Asked Questions
Is the wavelength label always the peak?
No. It may be a nominal value, centroid or another specified parameter. The worked component example lists a peak of 860 nm and centroid of 850 nm. Read the parameter name and conditions before comparing numbers.
What does FWHM tell me?
It describes the spectral width at half the curve's maximum height. It does not identify a second wavelength or establish hard emission boundaries. Tails can extend beyond the half-height crossings.
Does a relative curve show how powerful a device is?
No. Normalising a curve to its maximum shows shape and wavelength distribution. It removes the absolute scale needed for a power comparison. Look for suitable absolute measurements and their units instead.
Can I apply the component graph to a VanqHeal panel?
No. The component is not identified as part of the panel. It is used here solely as a real graph-reading example. A finished-device spectrum must correspond to the exact panel, mode and operating conditions.
Do multiple peaks prove that all modes work together?
They describe the emission present during that particular measurement. Check its mode and settings. A mixed-mode graph does not establish every selectable mode or the output of each channel separately.
Can a spectrum establish a treatment result?
No. It characterises light under measurement conditions. A treatment claim also requires appropriate evidence about the device, exposure, people and outcome. A wavelength match alone does not transfer another product's clinical findings.
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