VIPE™ Laser Technology: Why VCSEL Is the Third Generation of Light Care

In short: VIPE™ (VCSEL Intelligent Photonic Engine) is the light platform inside every Reseen device. It uses VCSEL lasers, a third-generation light source that follows LEDs and edge-emitting laser diodes. A VCSEL laser emits a narrow, round, low-spread beam at a stable wavelength, so more of each emitter's low-power light heads where the device points it instead of scattering.

Why the light source matters in light care

Most talk about light devices focuses on color. But the emitter producing that color shapes just as much of what reaches your skin. Five properties matter:

• Wavelength purity. How tightly the output clusters around its target wavelength. A "660nm" source may really spread across a range on either side.

• Beam divergence. How quickly the light fans out after leaving the emitter. Wide beams cover more area but thin out with distance.

• Wavelength stability. Semiconductor light sources drift in wavelength as they warm up. Some drift far more than others.

• Heat. Higher-power sources warm the device and the skin beneath it.

• Delivered light. The share of light that reaches the intended area rather than spilling sideways, which ultimately sets irradiance at the skin.

Generation 1: LEDs

An LED produces light through spontaneous emission: electrons and holes recombine and release photons in random phase and direction. The RP Photonics Encyclopedia notes that LED emission bandwidth is typically some tens of nanometers, often around 40nm, which it describes as much broader than for laser diodes. The same source explains that LED light has low spatial coherence and is originally emitted in all directions, so its beam quality is very low compared with laser diodes.

Strengths: LEDs are inexpensive, safe, and excellent at bathing large areas in light, which is why face masks and panels use them. A 2018 review by Heiskanen and Hamblin lists ease of home use and the absence of laser safety concerns among their advantages.

Limitations: Light spreads widely, weakens with distance, and covers a broader band than the number on the box suggests.

Generation 2: Edge-emitting laser diodes (EEL)

The laser combs and helmets behind classic low-level laser therapy (LLLT) devices typically use edge-emitting laser diodes. In an edge emitter, light travels along the chip and exits from its cut edge. Because it is a laser, the light is coherent and far narrower in spectrum than an LED's.

Strengths: Narrow wavelength, coherent output, and strong power from a single chip.

Limitations: The beam leaves the narrow edge of the chip and fans out unevenly. A 2012 comparison in Optoelectronics and Advanced Materials – Rapid Communications by Bodendorfer and colleagues found the edge-emitter's beam diverged more in one direction than the VCSEL's.

"The resulting elliptic beam profile is a major disadvantage of edge-emitters" — Bodendorfer et al.

Edge emitters are also more temperature sensitive. In the same study, the edge-emitter's wavelength shifted by 0.25nm per kelvin, against 0.05nm per kelvin for the VCSEL. And they are harder to manufacture at scale: Wikipedia's VCSEL entry notes that edge-emitters cannot be tested until the end of the production process, after the wafer has been cut into individual chips.

Generation 3: VCSELs

A VCSEL, or vertical-cavity surface-emitting laser, flips the geometry: light exits straight up from the chip's surface. That one change addresses most edge-emitter drawbacks:

• Round, low-spread beam. Bodendorfer and colleagues describe the VCSEL as having a homogeneous and circular beam profile, and Wikipedia notes that the design produces a lower divergence angle.

• Stable wavelength. The study's measured shift of 0.05nm per kelvin was a fifth of the edge-emitter's, so output stays closer to target as the device warms.

• Easy to test and array. Wikipedia explains that VCSELs can be tested at several stages on the wafer and built in two-dimensional arrays. That makes it practical to pack many small, low-power emitters into a thin, flexible surface.

• Proven at scale. VCSELs already run inside Face ID, computer mice, automotive lidar, and short-range fiber-optic communication, according to Wikipedia.

The trade-off: individual VCSELs put out less power than edge emitters. For low-level light care, that is a design fit, as the cold laser section explains.

LED vs edge-emitting laser vs VCSEL laser

What VIPE™ is

VIPE™ stands for VCSEL Intelligent Photonic Engine. It is Reseen's proprietary photonic platform and powers every Reseen device, building on more than 20 years of photonics research. Reseen's parent technology company, RAYSEES, designs and makes VCSEL semiconductor chips.

According to Reseen's VIPE™ page:

• Narrow spectrum. Light is concentrated in a precise wavelength range.

• Focused beam. Beam angle is under 20°, compared with conventional LEDs scattering at up to 120°.

• Low power, non-thermal. Output is under 5mW per emitter, with no heat-based disruption or downtime.

• More focused energy. Reseen's internal optical testing measured up to 30× more focused light energy than conventional LEDs under the same power conditions. Results vary by device design, wavelength, distance, and use conditions.

Cold laser and low-level laser therapy: why low power is the point

"Cold laser" is a common name for low-level laser therapy. Wikipedia describes LLLT, cold laser therapy, and photobiomodulation as names for applying low-power lasers or LEDs to the body without damaging tissue. "Cold" separates it from surgical and resurfacing lasers, which work by heating or removing tissue.

"not an ablative or thermal mechanism, but rather a photochemical effect" — Huang et al., Dose-Response

More light is not automatically better. That 2009 review by Huang, Chen, Carroll, and Hamblin describes a biphasic dose response: low doses often worked better than high ones, and beyond a certain point stimulation gave way to inhibition. Dose depends on fluence (energy per area) and irradiance (power per area), not just how bright a device looks. Under 5mW per emitter is a deliberate choice: many small, focused, low-power points rather than a few hot, powerful ones.

How VIPE™ shows up in each Reseen device

• Glow (available now) is a handheld facial wand with 39 emitters: 13 × 460nm blue, 13 × 660nm red, and 13 × 1064nm near-infrared. It adds EMS mode, steady 108°F warmth, and a gua sha glide for 5-minute sessions 3–5 times a week, designed for firmer-looking, more radiant skin.

• Weave (coming soon) is a laser comb with RootReach™: 660nm red laser light travels through each of its 36 teeth and is delivered at the tip, where it touches the scalp. Read how it works in RootReach™ technology.

• Halo (coming soon) is a wireless, flexible cap liner with FlexArray™: 256 light points made up of 128 × 660nm red VCSEL lasers and 128 × 460nm blue LEDs, for a healthier-looking scalp and fuller-looking hair. See FlexArray™ technology.

Honest limits

• Focus is a means, not an outcome. A tighter beam delivers light more precisely. It does not by itself guarantee a visible result.

• Consistency matters most. Light care works over weeks of regular sessions, not one use.

• Engineering is not a clinical result. Beam angle, spectral width, and output describe how light is delivered, not how any individual's skin or scalp will respond.

Frequently asked questions

Is VCSEL a laser?

Yes. A VCSEL is a semiconductor laser diode that emits from the chip's top surface rather than its edge. Its light is coherent and narrow in spectrum, unlike an LED's.

Laser vs LED for red light therapy: which is better?

Neither wins in every case. LEDs are inexpensive and cover broad areas well; lasers deliver narrower, more directional light suited to close-contact devices. A 2018 review by Heiskanen and Hamblin noted lasers were traditionally preferred, but LEDs have since become common in photobiomodulation.

What is the difference between VCSEL and EEL lasers?

An edge-emitting laser (EEL) sends light out of the chip's side in an elliptical, uneven beam, and its wavelength drifts more with heat. A VCSEL emits a round, low-spread beam from its surface, holds its wavelength more steadily, and can be tested and arrayed on the wafer.

Is a cold laser safe?

Low-level lasers work at low power and do not rely on heat. As with any light device, never look directly into the emitters and follow the instructions. If you have a skin or scalp condition or take photosensitizing medication, check with a dermatologist first.

Why does Halo combine lasers and LEDs?

Each source has a different strength. Halo pairs 660nm red VCSEL lasers, which deliver focused, narrow-spectrum light, with 460nm blue LEDs, which spread light broadly across the scalp's surface, and lets you run each mode alone or together.

Explore the science behind every term in the Reseen glossary.

Sources

1. Vertical-cavity surface-emitting laser — Wikipedia

2. VCSEL in interferometry: a comparison to edge-emitting diode lasers regarding their applicability in speckle-interferometry — Bodendorfer T, Heßke A, Sax C, Koch AW. Optoelectronics and Advanced Materials – Rapid Communications, 2012

3. Light-emitting diodes — Paschotta R. RP Photonics Encyclopedia

4. Photobiomodulation: lasers vs. light emitting diodes? — Heiskanen V, Hamblin MR. Photochemical & Photobiological Sciences, 2018

5. Biphasic Dose Response in Low Level Light Therapy — Huang YY, Chen AC, Carroll JD, Hamblin MR. Dose-Response (SAGE), 2009

6. Low-level laser therapy — Wikipedia

This article is for general education and is not medical advice. Reseen devices are cosmetic devices and are not intended to diagnose, treat, cure, or prevent any disease. Individual results vary. If you have a skin or scalp condition, talk to a board-certified dermatologist.