Having been through many product development cycles as an optical engineer, here’s the progression from my point-of-view:
Specification
An optical system specification contains all functional and performance requirements, such as what is being captured by the optics, what information we expect to retrieve, and at what resolution. In addition, it documents any practical considerations, such as system size, interfaces, candidate detectors, and expected environments.
Working with you to develop an optical specification that is clearly understood by all involved and that will ensure the resulting optics serve their intended purpose is an important part of my job as your optical design consultant. I leverage decades of experience as an optical engineer as well as a couple years in requirements flowdown.
Feasibility & Trade Studies
Once we have a specification, I investigate which optical design forms would best meet the requirements. I then do some calculations and preliminary raytracing to estimate the performance, size, relative cost, etc., so we can consider the trades between them.
Depending on the spectrum, field of view, detector size, contrast requirements, etc., certain design forms will stand out. For example, if you want to image a very distant and bright object that emits from the VIS through the MWIR, I would likely start with a variation of the Classic Cassegrain design form.
Optical Design
Once a design form is selected, I begin the optical design in Zemax.
Design Review
Before the design is finalized, I review it with you and incorporate any changes.
Drawings
I finalize the design, do a detailed tolerance analysis, and generate drawings and CAD for the lens fabricator and the lens mount designer, who in response, provide quotes and lead times. There may be design iterations based on the results of the tolerance analysis and feedback.
Prototype Manufacturing
Once the drawings are finalized, prototype manufacturing begins. The lens fabricator and mechanical designer often work in parallel. Lead times for precision lens fabrication are often 6-8 weeks. The mount design and fabrication is usually finished before they receive the lenses.
Verification and Validation
Once the prototype is assembled, it will be tested to verify that it meets all the requirements in the specification. Tests may be performed here in my lab, at the facility where the optics are mounted, or at a third party testing facility. You will also validate that the prototype is suitable for its intended use. That could be simply serving as an impressive proof of concept to excite investors into funding the next round or it could be meeting functional expectations in real-world use cases.
Design Improvements
At this point, the prototype has served it’s purpose, providing an optical proof of concept that stakeholders can evaluate. It has revealed any potential issues and areas for improvement, which will be addressed in the production design.
Although some of my prototype designs go straight to production, there are differences between prototype and production designs, beyond realizing improvements that simply weren’t obvious up front. For example, it may be beneficial to incorporate molded lenses into the production design. Molded lenses are usually too costly for a prototype, due to non-recurring engineering charges, but may be the most cost-effective option for high volume manufacturing.
Production
Depending on the size of your market, the next step will be either pilot or full-scale production. If there’s good demand for your product, this is when you can expect to see real rewards. As you get feedback from end-users and gain more exposure to the technology and market, that information can be incorporated into the next generation product.