1. Natural light illumination system Irfan Ullah Department of Information and Communication Engineering Myongji university, Yongin, South Korea Copyright © solarlits.com

2. Contents Introduction Indoor lighting system Static solar concentrator Coupler Optical switching Beam splitter Light pipe Light module Simulation Application Conclusions

3. Introduction Green energy has been gaining popularity Solar energy: natural lighting Illumination system –Collecting –Transmission –Lighting components Passive and active systems Top lighting and side lighting Concept of daylighting

4. Concept Static concentrator (prismatic and cascadable) Transmission (fiber coupler) –Multi-fibers to one fiber Light switching –To control and change the direction of light Beam splitter –High pass and low pass dichroic coating) Hybrid system –LED light + sunlight

5. Indoor lighting system Static concentrator (prismatic and cascadable) Illumination system –Light collection unit –Transmission unit –Lighting unit Architecture of Indoor lighting systemIndoor lighting system

6. Indoor lighting system cont’d.. Static concentrator (prismatic and cascadable) Illumination system –Light collection unit –Transmission unit (coupler and optical fiber) –Optical switching (red, green, and blue) –Lighting unit (lightpipe, optical sensor, and LED array) Static light concentrator

7. Static solar concentrator Inexpensive, easy to install, and without tracking Working –Sunlight→line beam→point soure Prismatic structurePrism array

8. Static solar concentrator cont’d.. Incident angle of sunlight Collector’s efficiency

9. Coupler Light from prismatic structure into fiber Light from multi fibers into one fiber Traditional coupler 2 x 1, efficiency = 7.65% Stepped coupler Coupler raytracing

10. Coupler cont’d.. Traditional coupling efficiency = 7.65% Stepped coupler efficiency = 50.28% Coupling efficiency Stepped coupler

11. Optical switching Radius fiber 1 and fiber 2 = 9 mm Radius fiber 3 = 20 mm Angle fiber 1 = ±40 Telecentric system: 20 mm Cubic structure size = 52 mm Curvature surface 1 = 0.086 Curvature surface 2 = 0.088 Efficiency = 32.23% Light switching Original optical system Optical system after second optimization Ray tracing

12. Beam splitter Fresnel lens layer on the incident and exit surfaces –Parallel beam –To achieve different wavelengths –Applied on top, left, and right surfaces Prism size: 52 mm x 52 mm x 52 mm –Fiber radius = 9 mm –600 (red), 550 (green), 480 mm (blue) cuteoff: 575 and 515 nm Dichroic prismDichroic mirror Beam splitter

13. Light pipe Dot pattern for light distribution Diameter = 16 mm Length = 150 mm Coupled efficiency = 91% Light pipe Fluorescent light

14. Light pipe IlluminationComparison of different dot patterns Light pipe designRay tracing

15. Dynamic light guide Dynamic lighting module: 5 light pipes and 100 LEDs Dimensions: 100cm x 100 cm x 4 cm Light pipe length = 100 cm ; radius = 9 mm Flux of each pipe = 1500 lm ; LED = 75 lm Parabolic reflectors = 5 ; receiver's surface area = 16 m 2

16. Dynamic light guide Illumination by sunlight Detected flux by sensor = 0.357 lm Average illuminance = 258 lx Surface area = 16 m 2 Detected flux by sensor = 0.18 lm LED’s emit 37.5 lm Average illuminance = 237.96 lx Illuminance distribution by hybrid lighting Illuminance distribution by LEDs Detected flux by sensor = 0.1 lm Average illuminance = 217 lx Summary of simulations

17. Ecological illumination system Lighting system for traffic tunnel Parameters of traffic tunnel Requirements for illumination

18. Ecological illumination system Chinese national standards K, Conversion factor of average illuminance N, Number of lamps U, Illumination rate M, Maintenance factor F, Total flux for singlw lamp L, Brightness requirement W, Road width Flux for each illumination section Collecting units

19. Ecological illumination system Frontal view of tunnel Six lampsSingle lamp

20. Conclusions Collecting part –Static prismatic concentrator –Stepped structure coupler with efficiency 50.285% Transmission part –Cubic structure light switch with efficiency 32.23% –Prismatic structure beam splitter Distribution part –Dot pattern with light pipe Hybrid system –LEDs light + sunlight

21. THANKS ?