Innovative modelling capabilities for freeform optics

Paul Boughton

Synopsys has launched a new version of its LightTools illumination design software that adds a new Advanced Design Module with robust capabilities for modelling freeform optics for a wide range of applications.

The new capabilities in LightTools 8.3 enable users to easily incorporate freeform surfaces in illumination designs to produce optical systems that have increased energy efficiency, improved light control and innovative design forms. It also adds new features for highly accurate design and modelling of phosphor based LED systems.

The new LightTools Advanced Design Module introduces a set of specialised tools for robust modelling of reflective and refractive freeform optics in both single surface and segmented configurations.

Using freeform optical surfaces provide many advantages over conventional optics for meeting complex illumination requirements, such as precise light control, innovative styling, compact system dimensions and energy efficiency.

In addition, the Advanced Design Module leverages proprietary algorithms from Synopsys’ LucidShape design tool that automatically calculate and construct optical geometries based on user-defined illuminance and intensity patterns. This unique, functional approach gives designers the freedom to focus on overall design objectives rather than the implementation details of complex optical components.

The Freeform Design features are aimed at modeling freeform reflective and refractive surfaces that are automatically shaped to form the resulting light pattern. These are especially advantageous for systems with small light sources, such as LEDs and halogen lamps.

The MacroFocal Reflector tool for designing multi surface segmented reflectors allows for different spreads for each facet. This is useful when designing lighting systems for applications that need precise control of the light pattern or sharp intensity cutoffs at one or more sides of the beam. Applications include street lights, outdoor and architectural lighting systems.

The Procedural Rectangle Lens tool is for designing surfaces with pillowed optical arrays, which enables precise light distribution control in LED luminaires and signal lighting, as well as in applications that require superposition of optical distributions.

The LED Lens tool is then used to create various types of freeform LED collimator lenses, which are effective for producing efficient, highly directed light distributions.

“As the lighting industry continues to evolve, LEDs have become integral components in architectural lighting, and the use of freeform lenses and freeform reflectors has led to new photometric design possibilities,” said Dr Matthias Bremerich, chief illumination engineer at system developer ERCO. “The new LightTools Freeform Design features enable us to develop these sophisticated optical parts. We are impressed by the accuracy and speed of these tools.”

“With the LightTools Advanced Design Module, designers have powerful new tools to streamline the design of innovative luminaires,” said George Bayz, vice president and general manager of Synopsys’ Optical Solutions Group. “Enabled by the Advanced Design Module features, illumination engineers can take advantage of the cost and performance benefits that freeform optics offer, such as the ability to produce small, energy efficient light sources with design characteristics tailored to their application requirements.”

LightTools 8.3 also includes new capabilities to assist designers in modelling spatial temperature and power density variations in phosphor based LEDs. Phosphors are known to change output under various conditions, including wide temperature ranges and changes in power density, and these are important to consider when modelling phosphor layers in applications such as high power white LED packages. It also adds a new application programming interface (API) that gives users a high level of flexibility for developing custom volume scattering components that can be dynamically linked with LightTools. The API is particularly useful for defining interactions in phosphor based LEDs.