Optical and optomechanical assemblies are made up of various optical and mechanical components. These assemblies are used in many critical industries and applications, so it is important to understand how to select and assemble the necessary components properly. Otherwise, the final product may not function, perform, or fit as intended. The process of creating a design that will result in a product that functions, performs, and fits as needed for the application is known as design engineering.
At JML Optical, we have the depth and breadth within our engineering department to address a wide range of optical and optomechanical challenges. We bring projects from initial design to prototype to end product by carefully engineering designs for size, weight, manufacturability, and a multitude of other factors.
What Is Design Engineering?
Optical design engineers design and build devices that serve as solutions to light-based problems. The designers must have a comprehensive understanding of the science of optics and how to apply the principles in a practical way to achieve this goal. This information enables them to successfully create optical parts and products that meet the requirements and restrictions of their intended applications.
The design engineering team at JML Optical can take your idea and develop it into a fully detailed, manufacturable design. Whether you need a single lens element, doublet, or full complex assemblies, our attention to design factors upfront ensures we can meet your quality and quantity needs. By working closely with your engineering team, we ensure a smooth transition from prototype to production.
We can also help you optimize your design for performance, size, weight, manufacturability, ruggedness, or whatever other factors are important to your application. Our vast experience designing and manufacturing optical and optomechanical assemblies that push the theoretical limits of performance gives us the knowledge and skills we need to deliver solutions that accommodate virtually any optical requirement or restriction.
Process, Manufacturing, and Metrology Engineering
The design engineering process encompasses all of the steps necessary to take an optical solution from prototype to product delivery, such as:
- Defining the product. The design engineers identify how the final product must look and work to suit the intended application. This information can include field of view, focal length, image quality, physical dimensions, and a variety of other product requirements and restrictions.
- Developing an initial design. Once the design engineering team has the above information, they can begin brainstorming and developing potential designs.
- Creating prototypes. After the initial designs are created, the design engineers use them to create prototype units for testing purposes. These tests can uncover issues that occur during production or within the final products, allowing the team to adjust the design or process to improve product performance or manufacturability.
- Manufacturing the units. When both the team and the client have approved the final design, manufacturing can begin.
- Testing and verifying the units. Completed units are subjected to final testing and verification before they are shipped to the customer to ensure they meet the necessary specifications and standards. Testing can be performed on all units or on a sample, as the situation requires.
- Delivering the products. Once the units are fully tested and verified, they are sent to the client.
At JML Optical, our design and process engineering team carefully executes all steps of the product development process to ensure that the delivered results offer the highest production yield and meet or exceed your performance requirements. Additionally, after product delivery, our engineers continue to make improvements to the process for future orders.
Optical Design Engineering Considerations
There are numerous factors design engineers must consider when creating an optical or optomechanical assembly. Six basic design categories in which they must make decisions are:
The optical system — the optical elements and their arrangement — is designed to meet a number of optical performance specifications. There can be literally dozens of specifications for a single optical system. Some of the most important ones include
- Focal length
- Object / Image distance
- Color spectrum
- Field of view
- Working distance
- Total track length
The choice of material is critical to a system’s performance capabilities and cost. It is important to choose a material that meets the demands of the intended application while not exceeding the project budget. Generally, optical glasses that are designated by the manufacturer as preferred types are easier and cheaper to process. Additionally, they are more likely to be available for future orders.
The designer will first consider the fundamental optical properties of the glass or plastic optical materials
- Index of Refraction determines how strongly the material can bend light for a given angle of incidence.
- Dispersion. The index of refraction varies with wavelength. This means that a single element has more optical power at some wavelengths than at others. The designer uses glasses with varying dispersion to ensure that the overall optical design has the same optical power over the desired range of wavelength.
The optical elements are normally mounted in a barrel or frame to hold them in the correct position. Important considerations for these materials include:
- Coefficient of thermal expansion (CTE). The materials used for connected parts should have compatible CTEs to minimize differential expansion or contraction during thermal changes.
- Density. If there are many acceptable material choices, the decision can be made based on density. A less dense material can be used to reduce the total weight of the end component.
- Heat treatment. Any critical metal parts that are rough machined should be appropriately heat treated to improve their dimensional stability.
Shock and vibration, temperature and pressure changes, and other environmental conditions can damage optical components or cause misalignment of optical systems. That’s why it is important to ensure the structural design has the right combination of strength, flexibility, and weight.
The performance of a refractive optical system depends on proper lens mounting and positioning. Some tips to follow include:
- Metal reference surfaces should interface with polished lens surfaces.
- Glass-to-glass edge contacts should be avoided in lens designs if acceleration forces are expected.
- Lens-to-mount interfaces should be designed for low axial contact stress.
Mounting Prisms and Mirrors
Reflective components, such as prisms and mirrors, have special mounting considerations. Some tips to follow include:
- Prisms and small mirrors should be mounted semikinematically, if possible.
- Larger mirrors should be supported at multiple points around their rims and on their backs.
Assembly and Alignment
Even the best optical system design would produce a useless assembly if it were not accurately assembled and aligned. That’s why optical engineers implement measures during both the engineering stage (e.g., optimizing the number of adjustments needed for fine alignment) and the assembly stage (e.g., carrying out assembly in a clean and dry environment) to ensure the creation of a successful product.
Engineering at JML Optical
The engineering experts at JML Optical are ready to help with your most difficult optical challenges. We deliver solutions for:
- Optical and optomechanical design
- Optics manufacturing
- Optomechanical assembly
- Optical metrology
Strategically positioned a few steps from the shop floor, our on-site engineers can easily integrate into product teams alongside our purchasing, fabrication, assembly, and metrology experts. By focusing on Design for Manufacturability (DFM), they help customers increase their production yield without sacrificing quality. Our engineering department works with many types of design software, including AutoCAD, Code V, Inventor, SolidWorks, and Zemax.
To learn more about our optical engineering services or partner with us on your next project, start a conversation with us today.