DPI® Lens arrays masters
DPI® (Dynamic Part Indexing) is a patented technology developed by Wielandts UPMT. This unique system brings the best ultra-precision machining technique, i.e. on-axis diamond turning, to produce arrays of all kinds. By shifting the workpiece with respect to the main spindle in a dynamic, balanced and ultra precise way, each surface of an array can be machined sequentially. With this technique, the outstanding form accuracy, surface finish and geometric freedom that is achievable by ultra-precision diamond turning on a single on-axis lens can be obtained on each lens of each array of a fully populated master.

DPI® brings many advantages compared to classical freeform machining techniques like amongst others: lower surface form error, reduced machining times, increased geometrical freedom, true 100% fill factor (with extremely sharp edges between intersecting lenses), lower surface roughness, etc, which makes DPI® a unique solution for your next lens array application.

Masters have been successfully manufactured for a broad range of customers’ applications like: polymer-on-glass replication for automotive illumination, lens arrays for augmented- and virtual reality, consumer goods sensors and imaging devices, medical applications, etc.

DPI® On-axis Diamond Turning
Shapes Aspheres, mild freeforms, each lens can have a different optical definition
Feature sizes > 10 µm
Lens sag > 10 µm, < 10 mm
Form irregularity 100 nm p-v
Ra roughness 2 nm
Edge slopes < 80°, limited by tool clearance
100% fill factor Yes
Position accuracy Lens to lens: < 1 µm
MLA to MLA: 1 µm
Diffractive structures Yes (axis symmetric)
Master size Up to 8”
Number of lenses Up to tens of thousands
Master material NiP, brass, PMMA, CuBe, …
DPI® Lens array DPI® Lens array
2 nm
Ra Roughness
100 nm p.-v.
Surface irregularity
< 1 µm
Position accuracy
Single Point Diamond Turning
Wielandts UPMT provides single-point diamond turning services for single parts and small series production of space mirrors, infrared lenses, prototype imaging or illumination lenses, … The company is equipped with State-of-the-Art ultra-precision machines operating in a thermally stable and vibration free clean room environment. Beside these machining equipments, a broad range of metrology instruments guarantee the utmost quality of every part that is manufactured.

The company can also offer in-house diamond fly-cutting and diamond milling, as well as rough turning/milling using conventional CNC machines. Combining different techniques for machining, fixturing and compensation, light-weighted parts can for example be machined with an extreme accuracy. Equipped with a fast-tool-servo, the company can also machine various types of freeforms in the most efficient way.

With these technologies and its highly skilled staff, Wielandts UPMT offers its customers a complete service from the bulk material to the finished part. Multiple projects have been successfully realized: mirrors for space instrumentation, observation, laser and UV, prototype imaging and illumination lenses, ZnSe infrared lenses, gratings, …

Single Point Diamond Turning Services
Materials Copper, copper beryllium, brass, aluminum, nickel-phosphor, germanium, zinc selenide, zinc sulfide, calcium fluoride, PMMA, polycarbonate, …
Geometries Spherical, aspherical, off-axis parabola, toric, ellipsoid, fresnel, diffractive, freeform
Size 1-450 mm diameter
Form irregularity 100 nm p.-v.
Ra roughness 2 nm
Dimensional accuracy < 1 µm
Industries Consumer, aerospace, OEMs, defense, medical, …
Metrology equipment
  • 4″ Fizeau interferometer
  • 3D confocal stitching microscope
  • Optical tactile profiler
  • Multi-sensor CMM
  • 3D CMM
  • In-machine microscopy, surface profiling (chromatic confocal probe), touch probe, …