Sandia Optical
FAQ

Common questions from engineering teams scoping a polymer-optics program.

Specific to molded polymer optics, PPAP, and the boundary between Sandia's responsibility and the customer's. If a question you have isn't covered, the contact form is a good way to ask.

Frequently asked

Nine questions, plainly answered

  1. Why molded polymer optics instead of glass?
    Polymer wins when the program needs aspheric and free-form surfaces at volume without grinding-and-polishing cost, when weight or impact resistance is a constraint, when integrated mechanical features reduce assembly complexity, or when the imaging band sits where modern optical polymers transmit cleanly. Glass still wins on absolute thermal stability, hardness, and certain UV or deep-IR bands; we will tell you when that is the case rather than push polymer for its own sake.
  2. What is injection molding for optics, briefly?
    Optical injection molding is the cycle of heating an amorphous polymer (Zeonex, Topas, optical PMMA, polycarbonate-class) to a melt, injecting it into a precision steel tool, packing under controlled pressure, cooling on a documented profile, and ejecting a part whose surface form, internal stress, and dimensional accuracy meet the optical release criteria — not just dimensional ones. All-electric presses, scientific-molding documentation, and a tight process window separate optical molding from commodity molding.
  3. Which polymers are most common, and when does each win?
    Cyclic olefin polymers (Zeonex, Topas) dominate where low birefringence and stable transmission across visible and near-infrared bands matter. Optical PMMA wins for cost-driven visible imaging with moderate environmental exposure. Polycarbonate is the go-to for impact resistance and thermal headroom at the cost of more birefringence. There are several others; the resources hub at /resources/common-polymers/ summarizes properties side by side.
  4. What do you need from us to start a project?
    A prescription or design intent (surfaces, materials, bands), the program's release criteria (form, wavefront, transmission, scatter, MTF, cosmetic), volume and timing, and any environmental or regulatory regime the part has to survive (sterilization, automotive thermal cycles, defense temperature and humidity envelopes). If you have a draft drawing and a target failure mode, that is enough to scope a DFM conversation.
  5. How do you handle tolerancing and PPAP?
    Tolerancing is set against the program's optical release criteria, not against an idealized glass surrogate. PPAP packages are built around the scientific-molding study (viscosity curve, gate-seal, cavity-pressure map), tool design documentation, capability studies on the relevant optical and dimensional characteristics, and the metrology-lab release evidence. The senior quality manager owns the submission; the molding process technician and tooling engineer own the process and tool evidence inside it.
  6. How does molding quality drive optical performance?
    Pack, hold, mold and melt temperature, and cooling profile all push back on internal stress, surface form replication, and gate-related defects — the three signatures that determine whether the part hits its wavefront, birefringence, and cosmetic spec. A dimensionally compliant part can still fail the optical bench; that is the failure mode the scientific-molding process is designed to prevent.
  7. What's your typical timeline from inquiry to first shots?
    Initial DFM and feasibility usually closes within two to three weeks of receiving the design and release criteria. Tooling lead times depend on cavity count and surface complexity but typically run eight to fourteen weeks from kickoff to first shots; aspheric and free-form surfaces sit at the high end. We will give you a program-specific schedule with the proposal — and we will tell you when the schedule is binding versus when it is conditional on tool-supplier slot availability.
  8. Do you do low-volume or prototype-only work?
    Yes, when it fits. Single point diamond turning supports prototype and low-volume polymer optics without a molded tool, which is often the right path for design-validation builds. We will scope SPDT-only programs when volume and unit-cost realities make it the right answer; we will tell you when molding will pay back the tool cost faster than SPDT will scale.
  9. What certifications and compliance do you carry?
    Sandia maintains ISO 9001:2015 (quality system), ISO 13485:2016 (medical-device component scope), and ITAR registration with the US Department of State DDTC. Certificate numbers, effective dates, and scope language are confirmed under NDA on a program-by-program basis. Programs that require AS9100D coverage should plan the customer-side flowdown accordingly.

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