NTS Optel usecase - optics experience center

Facial recognition as the key. 30,000 to 50,000 dots are correctly projected to ensure your smartphone knows it is really you. Optical wafer testing of optical elements optima forma.

Application | Optical wafer tester for optical elements.
Market segment | Semiconductor / Consumer market
Business activities | Tailored hardware and software of basic optical wafer tester design, manufacturing, installation, long term service and support.

What are the chances that your smartphone contains optical elements that are inspected by an Optical Wafer Tester that is designed and built by our engineering crew at NTS?

Answer: Very High! The top 10 mobile phones that have a facial recognition feature, contain optical elements inspected by an optical wafer tester built by NTS.

Today, pretty much every smartphone can use your face as a key. Although face unlocking is possible since 2011, technology has advanced and more and more phone manufacturers have been adopting this technology in their products.

For example Apple’s method, FaceID, uses and infrared camera, a depth sensor and a dot projector to map out 30,000 points on your face and creates an artificial 3D scan. This technology is also being used in to secure payments with Apple PAY.

The majority of Android phones today don’t have this level of face unlocking as of yet. But many smartphone manufacturers are following Apple’s footsteps. Recently Qualcomm announced their new processor can support infrared mapping technology up to 50,000 dots, which means more Android phones will get an improved facial recognition key this year. 

For facial recognition in smartphones a small optical element is used to diffract a laser source into a cloud of laser spots illuminating the face of a user in invisible light. This pattern, as observed by a camera in the smart phone, gives 3D-information and contributes to recognizing the person using the smartphone. These optical elements are produced in large quantities by replicating them onto a glass or plastic wafer. These elements have to be inspected to check their optical performance and quality and to guarantee laser safe operation. Just to make sure your face is correctly recognized in the end, safe and sound.


Application context

The NTS tailored optical wafer testers inspect the several hundred or even several thousands of optical elements on the wafer with inspection times of around 1-2 seconds per element. The tester generates a wafer map showing which elements have passed the test and can be used for further assembly and which elements have failed and need to be discarded.


Business benefits

For high volume inspection of MLA (Micro Lens Array) and DOE (Diffractive Optical Element) structures on wafer, or for final testing of optical modules, the NTS tailored testers ensure high reliability and throughput. Basic components of these modular designed testers are available off-the-shelf and can easily be tailored and combined to meet other product specifications and requirements.



Used techniques

The optical core of a tester comprises the laser module, to illuminate the optical element and a pattern imaging module that captures and images the pattern generated by the optical element. The laser module generates a light beam with precise specifications in terms of wavelength, beam shape, polarization and divergence. The pattern imaging module uses a group of custom lenses to capture the emerging wide angle pattern and project it directly onto a camera sensor or indirectly via a projection screen that is in turn observed using a camera. A computer controls the testers’ operation and performs the processing of the acquired pattern to come to a pass/fail decision.


Learn more about testing DOEs & VCSELs 

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