scholarly journals Diffractive optics based automotive lighting system

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Muhammad Shaukat Khan ◽  
Woheeb Muhammad Saeed ◽  
Bernhard Roth ◽  
Roland Lachmayer
Keyword(s):  
Optical Design ◽  
Field Of View ◽  
Automotive Application ◽  
Diffractive Optical Elements ◽  
Lighting System ◽  
Optical Elements ◽  
Projection System ◽  
Road Users ◽  
Projection Screen ◽  
Information Projection

AbstractInformation projection using laser-based illumination systems in the automotive area is of keen interest to enhance communication between road users. Numerous work on laser-based front end projection employing refractive and reflective optics has been reported so far, while for rear end illumination efforts are more scarce and a different optical design concept due to limited volumetric size and field of view regulations is required. Here, we report on a new and versatile approach for a laser-based rear end lighting system for automotive application which enables projection of information or signals to support other road users. The design is based on thin diffractive optical elements projecting the desired patterns upon illumination. Also, for protection of the road users from the steering laser beam, a diffusive back projection screen is designed to project information while fulfilling both the field of view and safety requirements. The projection system is based on a periodic diffusive structure made of an array of biconic lenses with sizes in the millimeter range. The field of view (FOV) from the simulated lens arrays complies with the angular requirements set by the Economic Commission for Europe (ECE). As a proof of concept, the diffusive screen is fabricated using microfabrication technology and characterized. In future, the screen will be combined with thin diffractive optical elements to realize an entire integrated projection system.

PROTOTYPING OF DIFFRACTIVE GRATING OPTICS FOR SENSOR APPLICATION BY AN INTEGRATED PROBE-BASED SYSTEM

2009 ◽  
Vol 06 (01) ◽  
pp. 1-12
Author(s):  
LO-MING FOK ◽  
YUN-HUI LIU ◽  
WEN J. LI
Keyword(s):  
Optical Design ◽  
Polymer Surface ◽  
Diffractive Optical Elements ◽  
Laser Beam Shaping ◽  
Optical Elements ◽  
Atomic Force ◽  
Manipulation System ◽  
Cost Efficient ◽  
Lens Surface ◽  
Lithography Technique

Diffractive Optical Elements (DOE) are often associated with the use of laser beam shaping equipment. They can be controlled and verified flexibly according to application. This paper demonstrates experimentally the lithography technique used to fabricate a DOE with precisely aligned pattern on a polymer surface. We have designed and fabricated a grating on the lens surface using the direct lithography by an Atomic Force Microscope. A description of the optical design is presented along with a discussion on the integrated manipulation system. The fabrication process has been proven to be cost efficient and reliable. It is believed that this technique can also transfer onto a complicated DOE.

scholarly journals Foveated near-eye display for mixed reality using liquid crystal photonics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Seungjae Lee ◽  
Mengfei Wang ◽  
Gang Li ◽  
Lu Lu ◽  
Yusufu Sulai ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Mixed Reality ◽  
Optical Design ◽  
Field Of View ◽  
Light Modulator ◽  
Projection System ◽  
Holographic Display ◽  
Optical Configuration ◽  
Display Performance ◽  
Cue Generation

Abstract Foveated near-eye display is one of the most promising approaches to deliver immersive experience of mixed reality. However, it is challenged to conceive a compact optical system. Here, we introduce a method to use polarization optics via liquid crystal photonics to improve the foveated display performance. We demonstrate a benchtop prototype of this idea. We implement and combine two display modules for peripheral and foveal visions. A peripheral display consists of a polarization selective lens (PSL) module, a polarization selective diffuser (PSD), and a slanted projection system. An 80$$^\circ$$ ∘ diagonal field of view is achieved by on-axis optical configuration of the PSL module and the PSD. A foveal holographic display is composed of a spatial light modulator (SLM), a volume grating lens, and a microelectromechanical system mirror possibly in combination with a switchable polarization selective grating module. The holographic reconstruction using the SLM enables accurate focus cue generation and high resolution above 30 cycles per degree within 15$$^\circ$$ ∘ by 15$$^\circ$$ ∘ field of view. We explore and discuss the liquid crystal photonics in the prototype that has a novel optical design using volume gratings with polarization selectivity.

scholarly journals Frequency Division Multiplexing of Terahertz Waves Realized by Diffractive Optical Elements

2021 ◽  
Vol 11 (14) ◽  
pp. 6246
Author(s):  
Paweł Komorowski ◽  
Patrycja Czerwińska ◽  
Mateusz Kaluza ◽  
Mateusz Surma ◽  
Przemysław Zagrajek ◽  
...  
Keyword(s):  
Frequency Division Multiplexing ◽  
Diffractive Optical Elements ◽  
Frequency Division ◽  
Terahertz Waves ◽  
Optical Elements ◽  
Telecommunication Systems ◽  
Wide Range ◽  
The Future ◽  
Wireless Telecommunication ◽  
Finite Distance

Recently, one of the most commonly discussed applications of terahertz radiation is wireless telecommunication. It is believed that the future 6G systems will utilize this frequency range. Although the exact technology of future telecommunication systems is not yet known, it is certain that methods for increasing their bandwidth should be investigated in advance. In this paper, we present the diffractive optical elements for the frequency division multiplexing of terahertz waves. The structures have been designed as a combination of a binary phase grating and a converging diffractive lens. The grating allows for differentiating the frequencies, while the lens assures separation and focusing at the finite distance. Designed structures have been manufactured from polyamide PA12 using the SLS 3D printer and verified experimentally. Simulations and experimental results are shown for different focal lengths. Moreover, parallel data transmission is shown for two channels of different carrier frequencies propagating in the same optical path. The designed structure allowed for detecting both signals independently without observable crosstalk. The proposed diffractive elements can work in a wide range of terahertz and sub-terahertz frequencies, depending on the design assumptions. Therefore, they can be considered as an appealing solution, regardless of the band finally used by the future telecommunication systems.

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