Optics and Optical Material for LED Applications (PH270)

SynopsisThe past few decades witnessed a rapid growth in the LED industry with an extensive proliferation of LED components, LED backlights, lamps, luminaires and illumination systems in the industry. Along with this rapid growth it is not unusual to find engineers who were not trained in the discipline of optoelectronics to find themselves getting involved in the development and manufacturing of optoelectronics components and systems such as LEDs, IRLEDs, optical sensors and detectors and related systems.

In other developments, consumers have become more and more sophisticated and discerning in their demands. As such, knowledge of the basics related to LED optics has become an important part of the engineers' curriculum, especially those involved in making LED and LED-related products. LED applications in domestic market includes high definition 3-D LED TVs, decorative mood lighting and general illumination. Application in the commercial sector ranges from message displays to large area video displays, portable LCD projectors to camera Flash LEDs. In the public arena there are illumination applications like street lamps, walkway lighting, solar-powered road signs and lighting as well as architectural lighting for building, bridges and monuments. In all these applications, special optical design and requirements are needed to fulfill the customer demands.

It is essential that engineers and personnel involved in R&D and products specifications of LED products have a firm grasp of the fundamentals of LED optics and optical materials.

With this in mind, this course is designed to provide the participants with a broad understanding of the practical aspects of LED optics, optical design, optical materials and its application to LED design and its end-products.

What You Will LearnConcepts in optics fundamentals like reflection, refraction and diffraction

• Various laws governing optics such as Snell's law, Fresnel loss, critical angle, etc
• Application of optics knowledge to LED applications including backlighting, luminaires for indoor and outdoor applications, LED traffic signals and large area video displays.
• Introduction to optical materials and their properties - mechanical, optical, and thermal.
• Brief overview of optical design software and capabilities

Who Should AttendThe primary target audience for this course is for people involved in product marketing, test and development, characterization, design and development, quality and reliability, failure analysis, field applications and customer returns of LED components, products and systems.

This course is also applicable to a broad audience from various industries who needs to have strong basic understanding of the various concepts, terms and technologies of optics and optical materials used in LEDs and LED-end products.

Examples of target audience:

• Project Managers
• Program Managers
• Test Engineers
• Mechanical Engineers
• Quality and Reliability Engineers
• Failure Analysis Engineers
• Technical Marketing and Sales Engineers

PrerequisiteInterest in the science of optics applied to LEDs and end products and the desire to acquire better understanding in this area. Technical background in electrical/electronic/mechanical engineering or physics degree would be desirable.

Course MethodologyClass room training.

Course Duration2 days, 9am - 5pm

Course StructureFundamentals of Optics

• Electromagnetic wave theory
• UV, visible and infrared light
• Reflection, specular, and diffused
• Mirrors, concave, and convex
• Refraction
• Snell's law
• Light transmission and transmissivity
• Light diffusion
• Lenses and collimation
• Diffraction, prisms, and gratings
• Diffractive optical elements
• Gradient index optics

• Plastic encapsulated LED lamp package
• Flat SMT package
• Lensed SMT package
• High power LEDs
• Fresnel loss
• Critical angle loss
• Transmission loss
• Reflection and absorption loss
• Optical efficiency
• External quantum efficiency
• Internal quantum efficiency
• Luminous intensity and optical flux
• Calculating radiated flux
• Optical design and simulation
• LED source models
• IES file formats, EULUMDAT
• Interpreting photometric reports - LM-79 data
• Contrast enhancement for LED displays
• Eye response, peak wavelength, and dominant wavelength
• Wavelength filtering
• Filter transmittance and filter selection
• Louvered filters
• Polarizing filters
• Anti-reflection filters and mountings

• Backlighting - LCDs, instrument panels and legends
• Downlights
• Spotlights
• Omni-directional lights (bulbs-replacements)
• T8 LED tube replacements
• Energy star requirements
• Camera flash lights
• LED light projector
• Color-wash application
• Viewing angle and traffic signals
• Viewing angle and large area video displays
• Street and roadway Lighting - optical design requirements
• Roadway lighting classification - distribution patterns type I to V
• Light cut-off angle
• Glare index
• CRI
• Beam angle
• Flux zonal distribution

• Optical materials and their physical properties, mechanical properties, thermal properties, and optical properties
• Lenses
• Gradient index
• Diffractive optical elements
• Physical properties: density
• Mechanical properties: tensile strength, hardness, fracture and impact strength
• Thermal properties: melting point, heat deflection temperature, thermal conductivity
• Optical properties: refractive Index, measurement method, dispersion formula, refractive index and TIR, refractive index and Fresnel losses, transmissivity

• Optical sources
• Optical components
• Optical system
• Overview of software: sequential vs non-sequential ray tracing software, imaging software vs illumination software, ASAP, TracePro, etc.
• Building the geometrical model
• Importing from CAD files
• Setting up optical modeling: units, wavelengths, media, coatings, defining geometry, defining source, point source vs area light source, source modeling
• Running program
• Viewing plots and results
• Importing ray source models, files