Design and Modeling of Light Emitting Nano-Pixel Structure (LENS) for High Resolution Display (HRD) in a Visible Range

Abstract

LENS (Light Emitting Nano-pixel Structure), a new nano-metric device, was designed, simulated, and modeled for feasibility analysis, with the challenge of combining high resolution and high brightness for display, essentially adapted for Augmented Reality (AR) and Virtual Reality. The device is made of two parts: The first one is a reflective nano-cone Light Emitting Device (LED) structure to reduce the Total Internal Reflection effects (TIR), and to enable improved light extraction efficiency. The second part is a Compound Parabolic Concentrator (CPC) above the nano-LED to narrow the outgoing light angular distribution so most of the light would be “accepted” by an imaging system. Such a way is drastically limiting any unnecessary light loss. Our simulations show that the total light intensity gain generated by each part of the pixel is at least 3800% when compared to a typical flat LED. It means that, for the same electrical power consumption, the battery life duration is increased by 38. Furthermore, this improvement significantly decreases the display thermal radiation by at least 300%. Since pixel resolution is critical to offer advanced applications, an extensive feasibility study was performed, using the LightTools software package for ray tracing optimization. In addition to the simulation results, an analytical model was developed. This new device holds the potential to change the efficiency for military, professional and consumer applications, and can serve as a game changer.

Performance Enhancement and Applications Review of Nano Light Emitting Device (LED)

“…Second, the LENS device enables high values of TER even for a small current, while the LED structure requires higher current values to enable some light emission. The better results shown above for LENS do not consider the light reflections on the internal reflective walls, as previously published [16].…”

“…This means that the optical ray tracing software previously used to build the LENS device [ 15 , 16 ] is unable to predict the light behavior in sub-wavelength apertures, since this is not in its scope. Smaller and smaller pixels are of obvious interest and physical software contributes to a better understanding of sub-wavelength pixel efficiency and far field distribution.…”

“…Classical radiometry and common Monte-Carlo ray tracing cannot perform such investigation [ 34 , 35 ]. Previous presented results of the device are mainly dedicated to the study of the rays optimal tracing [ 16 ] using LightTools software platform [ 36 ] and are also limited to micrometric scales. While choosing Comsol Multi-Physics Software Package [ 37 ], complementary investigations were oriented to physical and opto-electronics behaviors of the device, as presented below in next series of results.…”

“…A monochromatic pixel array will allow us to reduce the pixel spacing, increasing the pixel density. Regarding the light beam angular distribution control, an optical condenser module, such as a compound parabolic concentrator [ 16 ] is considered to control the angular distribution of the light beam outgoing the pixel. Indeed, the numerical aperture is different depending on the system.…”

“…When compared to a conventional flat shape LED, it was previously demonstrated that when combined, the cone nano-LED and the CPC parts improve the power efficiency by around 3800%. Initial publications of such super-high intensity nano-emitting (SHINE) pixels [ 15 ] and LENS have recently been presented [ 16 ], when the analysis is based on the ray tracing method. In the current article, we complete the previous ray tracing analyses by adding physical studies of the device’s behavior when varying physical parameters such as dimensions, geometry, wavelength (RGB), carriers’ concentration, efficiency and more.…”