What we do
We do illumination optical design on a contract basis for makers of instruments and machines. We put the light where you want it.
There are three main steps in any design job:
- Understand the project
- Design the optics to satisfy system requirements
- Present measurable design results, along with specs for optical parts in a format compatible with your manufacturing process.
1: Understand the project – Each job is different. First we work with the client to define what’s needed. We offer a proposal stating what the client wants, and how to decide when we’ve got what we want. We can do that in several phases, each limited by a “not to exceed” cost. We offer a detailed design of one or more optical components. We can contract for the first phase, or for the entire job.
The light source is the most important part of any illumination design! If you don’t know where the light is coming from, all the calculations in the world will not tell you where it goes.
Do you need to know this much about the light source to get started? No; manufacturers’ data are usually sufficient to make a satisfactory model. Every type of light source is different, but within a type (LED, arc, filament) it emits in a known pattern.
Where should the light end up? Where is the target surface? How much light does it need, and in what spatial pattern? This is the customer's desired performance specification. Our job is to direct light to the specified target by selecting, designing and arranging optical components to make this happen. Knowing where the light starts, and what optics it encounters, we can calculate where it goes.
2: Design Optical Components - What's in the system? In general, the more parts we put into a system, the worse it gets. Every optical component introduces loss, scatter, and cost. A single reflector or lens is ideal – if it’s the right shape, in the right place. Figuring out shape and location of optics is the task of illumination design. We do it with our TRACE program, developed over the years in response to real problems on real jobs. Today the program’s abilities are always increasing to deal with today’s new sources and new fabrication methods.
Most jobs we do call for reflective optics – and a reflector can be one of many materials – solid polished metal, plated metal, coated plastic or ceramic, glass, water, soap film, or the surface of an organic product like a coffee bean. Whether you are sorting beans or shaping a laser beam, the contour and material and color properties of any reflector are important. We specify shapes and sizes, provide CNC lists for generating surfaces, and where needed, we measure the reflecting surface material’s texture and spectral behavior. With LED’s, thermal properties of mounting materials may be even more important than their behavior as optics.
Optical components can be very expensive - only the client can make overall cost decisions. We work with you to find solutions right for your company and for your customers. Spun metal reflectors, electroforms, plastic moldings, glass moldings and diamond-turned optics all differ greatly in cost. A financial choice also depends on quantity to be manufactured, and on detailed accuracy specifications. In the selection of components, you, the client, are the most important input to our work.
3: Design results – Usually the main result is a detailed design of one or more optical components, and a quantitative description of the delivered light pattern. Depending on the client’s need, we can also provide mechanical design of related parts, or thermal analysis, or tolerance studies. Once a satisfactory optical system is designed, we can calculate light distribution and delivery, and present that data in the form most useful to you.
What else does SSG do?
Byproducts of our experience can help you with other tasks:
Legal Support: Helen Gourley has served as an expert witness in patent disputes, civil trials, and insurance claims. She has provided optical evidence for criminal cases.
Evaluation of Surfaces: The SSG laboratory houses a special-purpose Nomarski microscope system for imaging detail of opaque materials like mirrors and diffusers. With that instrument we can photograph surface defects in high-precision, high-cost optics, and locate manufacturing problems in small parts.
Explaining: If you need to understand some obscure optical terminology, or just get up-to-date on new light sources, Ms. Gourley is an experienced explainer, certified to teach electro-optics in the California State University system. She can convey technical ideas to your engineers, your customers, or even your managers.
In the picture below she teaches at the annual San Francisco State sessions for teen-age girls interested in science. All these students in the classroom are getting familiar with their new laser pointers.
What don’t we do?
Some fields are large established operations, and already have a body of optical specialists. We design for specific devices, and don’t participate in street lighting, automobile head lights, or household replacement bulbs, all highly specialized areas employing highly specialized experts in the field. "I prefer working on the unusual optics needed for unique tasks", says Helen.
Call 415-586-3818 or send an e-mail to have a confidential discussion about your optical design project. SSG can immediately FAX you a signed non-disclosure agreement guaranteeing that the project, including any data you give us, remains entirely confidential.