What's Missing from Your Optical Design Flow

Groot Gregory

Nov 25, 2024 / 4 min read

In optical design, overlooking critical elements in your workflow can lead to inefficiencies and suboptimal results. By identifying common gaps and leveraging Synopsys optical design tools, you can enhance your design process for improved outcomes.

Optical design has evolved over the past decades from simple telescopes with hand-calculated prescriptions to nanometer structures fabricated with lithography. Traditional imaging systems have moved to smaller devices for consumer electronics with the aid of computer design tools and various fabrication methods.


Identifying and Filling the Gaps

Specifications

The specification stage is crucial in defining how the system needs to perform across multiple parameters. The following aspects are considered:

  • Imaging: Are you evaluating the Modulation Transfer Function (MTF) and aberrations appropriately?
  • Radiometric: Is your focus on achieving uniformity and contrast?
  • Sensitivity: How responsive is your system to various light levels?
  • Packaging: Are you considering size and weight constraints effectively?
  • Assembly: Is your centration and alignment process efficient?
  • Signal Processing: Are you enhancing system performance through effective signal processing?
  • Starting Point: Are you conducting thorough analyses and iterative adjustments?
  • Fabricate: Have you validated your design and transitioned to full-scale manufacturing?

Key Considerations

A typical design workflow begins with the optimization of imaging optics to meet rigorous design requirements and progresses to tolerance analysis performed during design iterations with fabrication tolerances included as part of the optimization performance. This crucial step enhances manufacturing yields and reduces costs. The workflow also integrates stray light analysis, allowing designers to evaluate the effects of unwanted light during the design phase and minimize failures caused by ghosts and flare.

Using CODE V for Imaging System Design

  • Imaging System: Ensure accurate mapping of points in space to points on an image.
  • Lens Design: Optimize design variables effectively.
Lens Design: Optimize design variables effectively

  • Sell Progress: Use performance metrics to communicate progress to stakeholders.
Sell Progress: Use performance metrics to communicate progress to stakeholders

  • Tolerancing: Evaluate performance variations due to manufacturing errors.
Tolerancing: Evaluate performance variations due to manufacturing errors

Using LightTools for Illumination Optics

  • Mounting and Packaging: Maintain lens alignment and consider packaging iterations.

  • Subsystem: Conduct radiometric simulations of lenses with mounting.

  • Stray Light Analysis: Identify and resolve stray light issues iteratively.
Stray Light Analysis: Identify and resolve stray light issues iteratively

Optical Scattering Measurements

  • Scattering and Surface Characterization: Characterize surface scattering using BSDF measurements.
Scattering and Surface Characterization: Characterize surface scattering using BSDF measurements

  • Sensor Data as BSDF: Use detailed camera BSDF measurements to access stray light due to the sensor.
Sensor Data as BSDF: Use detailed camera BSDF measurements to access stray light due to the sensor

  • System Analysis: Introduce meta surfaces and nano atom design flows.
System Analysis: Introduce meta surfaces and nano atom design flows

Integrating Metaoptics

Much like freeforms, metasurfaces offer new design parameters that expand the design space and are particularly useful when small packages are needed for weight and size reduction. From aspherics to metasurfaces, advances in fabrication methods provide increased options for designers, but with the added consideration of how best to specify component parameters for manufacturing.

Meta surfaces, such as metalenses, utilize subwavelength nano-atoms to create phase profiles without diffraction. These thin and flat surfaces save space and can be mass produced using mature lithography technology.

A design-aware flow targets first-time-right designs, reducing the need for redesigns.

A design-aware flow targets first-time-right designs, reducing the need for redesigns.

You can use MetaOptic Designer, an inverse design tool that takes user-specified criteria and generates metalenses/metasurfaces for optimal design performance. MetaOptic Designer’s built-in engineering intelligence allows designers at all levels of expertise to create novel metalens designs quickly and easily.

Sensor Simulation

ImSym - Imaging System Simulator, for image simulation, is a new tool combining imaging, stray light, and Image System Processing (ISP) into a seamless workflow. ISP can be developed to remove aberrations, like distortion, as well as improve the performance in the presentence of ghosts and flare. Creating additional optical structures, including backend layers and microlens, complete the sensor design.

The incident optical signal can be converted to a 3D Absorbed Photon Density (APD) profile to understand the sensor light absorption. Finally, the structure and APD file are used to simulate the device's electrical properties and evaluate performance data to ensure the design meets specifications.

Optical Design Flow Summary

By identifying and addressing what's missing in your optical design flow, you can achieve a more efficient and effective process. Synopsys tools can help you fill these gaps comprehensively, from specification to full-scale production, ensuring that every stage of your optical design is optimized for success. Advances in optical design and manufacturing workflows are not just improving traditional optics but are also shaping the future of consumer electronics and beyond.

Synopsys Optical Design Tools