Chongfan Technology
News
23
2025
-
06
Achromatic diffractive waveguide in AR glasses
Author:
AR glasses seem to have developed rapidly in recent years; many believe this is the device most likely to replace smartphones in the future. Many consumer market manufacturers in China, such as Thunder Bird Innovation, XREAL (Younai Koen (Beijing) Technology Co., Ltd.), Rokid (Hangzhou Lingban Technology Co., Ltd.), and INMO (Sichuan Yingmu Technology Co., Ltd.), are also involved.
A core component in AR glasses is the waveguide, which plays a key role in augmented reality devices. Waveguides utilize the principle of total internal reflection to transmit information, providing users with an immersive visual experience.
Key indicators for waveguides include:
-
Field of View (FOV) : Determines the range of virtual images the user can see; a larger FOV provides a wider field of vision. -
Eye Box : Refers to the range of movement for the user's eyes; a larger eye box improves wearing comfort. -
Diffraction Efficiency : Affects image brightness and clarity; a highly efficient diffraction waveguide reduces light loss and improves display quality.
These indicators together determine the performance of the diffraction waveguide, which in turn affects the overall AR glasses experience.
The most mainstream waveguide implementations are geometric waveguides and diffraction waveguides . Geometric waveguides have good optical performance with essentially no noticeable chromatic aberration. However, the manufacturing yield is very low, posing significant mass production challenges ( To achieve pupil expansion, geometric waveguides require many layers of film with different reflection/transmission efficiencies within the waveguide; the film system is very complex ).
Currently, diffraction waveguides are a viable implementation approach. Their manufacturing process is less complex than that of geometric waveguides, but they exhibit noticeable chromatic aberration. This is because the inherent dispersion of diffraction makes it difficult to achieve ideal achromatic results. Much current work is using SiC material; its high refractive index provides greater design space and allows for stronger chromatic dispersion compensation. Simultaneously, there is much research on non-local structures, which may overcome the technical bottlenecks of insufficient chromatic dispersion compensation and mode impedance mismatch caused by the limited resonance bandwidth and scattering ability of traditional local structures.
Currently, much research focuses on achieving achromatic information image transmission with high integration and thin, lightweight single-layer diffraction waveguides. Several similar studies have been published recently. The author has also attempted to design similar structures, with the following diffraction efficiency:
I've always had a question about diffraction efficiency, It's said that the efficiency of diffraction waveguides is low. Is it really that low? Or is it because pupil expansion necessitates low single-emission efficiency? In addition, the uniformity of diffraction efficiency is also very demanding in practical applications; otherwise, the rainbow effect will be very obvious. Should the priority of uniformity in three-color efficiency be higher than diffraction efficiency in design? ？
I wonder if any friends from the industry or those very familiar with engineering design have seen this post and would like to discuss it.
Is there much significance in simply designing a diffraction waveguide with ultra-high efficiency and achromatic single layer? I have been considering designing diffraction waveguides by setting refractive index discontinuities in the periodic structure and optimizing the position of the refractive index discontinuities to find suitable structures. However, I don't know what the appropriate objective optimization function is (mainly because I don't understand the priority of performance indicators for diffraction waveguides in practical applications).
LATEST NEWS
2025-06-06
Photonic avalanche nanocrystals with >500-order optical nonlinear response
At the forefront of nonlinear optical materials research, photon avalanche (PA), a unique luminescence mechanism occurring in lanthanide-ion-doped systems, exhibits exponential response under continuous laser pumping through an energy positive feedback loop mechanism, thus demonstrating ultra-high-order nonlinear optical behavior far exceeding traditional upconversion processes.
2025-06-05
Ji Xingchen/Su Yikai LPR | 780 nm on-chip integrated high-Q ultra-wideband Fabry-Perot cavity
With the rapid development of applications such as quantum precision measurement, atom manipulation, and narrow linewidth lasers, higher and higher demands are placed on high-performance photonic devices operating in the visible and near-visible wavelength range (especially the 780 nm wavelength corresponding to the rubidium atomic transition).
2025-06-23
Binary optics and metasurface lenses
Bichromatic optics is a subject or an optical technology; the concept of a meta-lens is more inclined to be a device.
2025-06-23
Achromatic diffractive waveguide in AR glasses
AR glasses seem to have developed rapidly in recent years; many believe this is the device most likely to replace mobile phones in the future.
Thank you for visiting the official website of Chongfan Technology. If you have cooperation intentions or suggestions, please contact us through the following methods, and we will reply as soon as possible, thank you!
Address: Room 403, Building 6, Phase III of R&D, No. 36 Xiyong Avenue, High tech Zone, Chongqing, China.
Telephone: +86-13658337211
E-mail: Sales@cfkeji.net
Website: www.cfkeji.net
Mobile Version
