Sandia Optical
Diffractive Optics

Diffractive optics — for the lightweighting and achromatization that refraction can't reach.

DOEs and multi-order diffractive lenses are not a marketing flourish; they are the right answer for programs that need lightweight, achromatic, or pattern-generating optics in a single element. We design them, we cut them on SPDT in-house, and we route binary and multi-level photolithography work through a vetted partner.

Kinoform · MOD · Hybrid refractive-diffractive
DOE & MOD design

Where a diffractive element earns its place in the optical train.

A diffractive optical element is the right call when the program needs a single thin element to do what a thicker glass stack does — and when its dispersion characteristic (opposite sign to refraction, larger magnitude) can be used to flatten chromatic aberration with one extra design variable instead of a second glass.

Multi-order diffractive lenses extend the bandwidth of a purely diffractive design by an integer m, turning a phase step from 2π into 2π·m and keeping the diffraction efficiency high across the band the program actually cares about. The design lives in Zemax with custom user-defined surfaces, with Monte-Carlo tolerance against the manufacturing envelope our SPDT bay or the partner litho process can deliver.

MOD vs. refractive

Same focal length, ~80% thickness reduction, achromatized over the design band.

MOD vs. refractive achromat A · Refractive achromat 2 elements · full glass mass Achromat: blue + red on axis B · Multi-order diffractive 1 element · ~80% thickness reduction Achromatized over defined band Thick glass stack Stepped MOD profile Equal focal length
MOD lens compared to a refractive achromat — both elements at equal focal length.
Fabrication routes

Two paths — chosen by volume, geometry, and the achromatization budget.

SPDT (in-house)
Kinoform DOEs and multi-order diffractive lenses cut on our SPDT bay with slow-tool-servo or fast-tool-servo profiles — see the SPDT capability for machine specifics. Used for low-to-mid volume and for the optical inserts that feed the molding floor.
Photolithography (partner)
Binary and multi-level DOEs through a vetted external photolithography partner. We own the design and the metrology side; the partner owns the litho and etch. Cost crossover with SPDT at high volume.
Application examples

Four programs where diffractives are the right tool.

NIR illumination shaping
Beam-shaping DOEs for laser and SLED illuminators in NIR sensing — uniform top-hat, ring, line, or custom intensity profiles tuned to the sensor's response.
HUD virtual-image generation
Hybrid refractive-diffractive elements for combiner-side and projector-side HUD optics where lightweight, wide-band achromatic performance is the design target.
Beam splitting and structured light
Dammann gratings and structured-light projectors for depth sensing, biometric capture, and machine-vision systems that need a known illumination pattern at the work plane.
Lightweighting refractive replacement
Large-aperture MOD lenses replacing thick refractive doublets where weight, thickness, or thermal stability drive the polymer-versus-glass call. See the technical illustration for the geometry comparison.
Measurement

What we measure on every diffractive element — and how it travels with the part.

  • Twyman-Green interferometry for transmitted and reflected wavefront on the diamond-turned surface.
  • Surface profilometry for groove depth, slope error, and form across the diffractive zones.
  • MTF through-focus measurement on the assembled element where the design targets imaging performance.
  • Spectral transmission across the design band; out-of-band suppression characterized where the application calls for it.

Tell us the optical envelope — we'll tell you whether diffraction is the right tool.

Lightweighting, achromatization across a defined band, and structured-light shaping are the three places DOEs and MODs land an unambiguous win. Send us the prescription; we'll write the manufacturability read.

Discuss a DOE project