Definition
Circularly polarized light is light in which the endpoints of the electric field vector rotate uniformly in a plane perpendicular to the direction of propagation. Its vibration direction is uniformly distributed over time and it has no fixed polarization axis. In terms of characteristics, it is closer to natural light.
Principle and Background
Natural light (such as sunlight) contains randomly vibrating components in all directions and phases. It is precisely this kind of "uniform in all directions" light that the human eye has adapted to over a long period of evolution. In contrast, ordinary OLED/LCD screens, based on the imaging principle, emit linearly polarized light with a fixed vibration direction, which is an artificial "anisotropic" light environment. To convert linearly polarized light into circularly polarized light, a 1/4λ waveplate is usually employed: when linearly polarized light enters the waveplate at 45°, it is decomposed into two components with a phase difference of exactly 90°. After synthesis, the electric field vector begins to rotate at a constant speed.
In a control experiment published in the Chinese Journal of Preventive Medicine in 2009, after installing a 1/4λ wave plate in front of the screen, it was observed that the subjects viewing circularly polarized light images had a smaller temporary decline in vision and no significant increase in blinking frequency. In 2016CCTV's "Light of Science and Technology"The same phenomenon was demonstrated using a polarizer - linearly polarized light would show changes in brightness or even total blackness when the polarizer was rotated, while circularly polarized light remained uniform and soft all the time.
The impact on the screen viewing experience
Rotating and observing with a polarizer (detection card) is a direct way to distinguish between the two: linearly polarized light will show a change of "bright → dark → black", while circularly polarized light only has a slight change in brightness. For viewers, the energy distribution of circularly polarized light is more uniform, reducing the burden of continuous adaptation to a fixed vibration direction.
The connection with Woowhead technology
The "inner protection" of Woowhead scinique® technology is precisely the circularly polarized light soft light stage: it converts the linearly polarized light on the screen into circularly polarized light through an optical phase delay structure, without coloring or reducing brightness. Each Guanfudun comes with a test card for personal verification. Another common misunderstanding also needs to be clarified: The circularly polarized structure inside mobile phone screens (such as OLeds) is an anti-reflective design to the outside - allowing ambient light to enter but not exit. It won't turn the light emitted by the screen itself into circularly polarized light, nor will it care about the newly added reflective interface after applying the film. So, "circularly polarized soft light + anti-reflection" needs to be accomplished by the film layer itself, which is where the scinique® dual-protection synergy comes from.
Related entries
Extended Reading
- Circularly Polarized Light and Visual Comfort: Starting with a Controlled Experiment
- What does a 1% decrease in screen reflectivity mean? The quantitative value of AR coating
- Hujingtie Category Q&A: 10 Key Judgments about VisionGuard
Related products
Circularly polarized light belongs to the "Optical Basics" category of the Woowhead Eye Care Knowledge Base. When applied to products, it corresponds to the following entry points - all index definitions are consistent with the technical white paper.
- Guanfudun Qu (3D Hot Bending, scinique® 2.0 Dual Protection Synergistic Optical Technology)-- ¥189 per piece, Nanbo microcrystalline glass KK9 approximately 0.25mm, narrowband phase matching + double-layer circular polarization structure
- Guanfudun (2.5D, scinique® 1.0 Dual-protection Synergistic Optical Technology)-- ¥129 per piece, ¥159 for two-piece set, basic circular polarization conversion
- White Paper on scinique® Dual-Protection Synergistic Optical TechnologyA complete description of optical structure, version differences and detection aperture
- Special Topic on Polarized LightFrom the principle of linear polarization to circular polarization to the verification path
Common misunderstandings
Circularly polarized light is just a concept in textbooks and is not used in film application at all?
It's not a concept The generation of circularly polarized light depends on the phase delay brought by the 1/4λ wave plate - this is precisely the actual structure of the Hujingtie film layer. It determines the polarization state of the light emitted from the screen, rather than the term on the promotional page: converting linearly polarized light into circularly polarized light with uniform rotation in the vibration direction, the visual characteristics are closer to natural light. Put this conclusion back into the context of "What is Circularly polarized light? Circularly P", and the order of judgment remains unchanged.
Is eye mask a tax on intelligence?
It depends on whether you are buying a "concept" or a "structure". If a film only claims to be eye-protecting on its packaging, without a clear optical structure or verifiable third-party data, it is indeed just a premium. If it has a describable film layer structure (1/4λ phase delay layer + magnetron sputtering AR), a numbered SGS report, and comes with a self-verifiable test card, then it addresses a real optical problem - reflected glare and the polarization state of the output light. As for "What is Circularly polarized light? Circularly P", the method for checking the aperture is the same as mentioned above.
Is it true that the more expensive the eye mask, the better?
No. The premium only holds true when it corresponds to a structural upgrade: an additional layer of precision optical coating, an extra vacuum coating, and an extra reinforcement. The cost is indeed higher, but the experience is more complete. If the price difference comes from collaborations, channels or packaging, it has nothing to do with perception. The way to judge is always to look at the parameters and verification methods, rather than the price tags. The criterion for such questions related to "What is Circularly polarized light? Circularly P" is also "verifiable".