Overview
EN ISO 14880-2:2024 - "Optics and photonics - Microlens arrays - Part 2: Test methods for wavefront aberrations" (adopted by CEN as EN ISO 14880-2:2024) specifies standardized laboratory methods to measure wavefront aberrations of microlenses in microlens arrays. Applicable to very small lenses formed on or within one or more surfaces of a common substrate, the standard defines measurement arrangements, apparatus requirements, procedures, evaluation rules, uncertainty assessment and test-report content for quality and conformity testing.
Key topics and technical requirements
- Scope and terminology: Uses terms from ISO 14880-1 (vocabulary) and gives symbols such as Φ (wavefront aberration), P‑V (peak‑to‑valley), rms, λ (wavelength), NA (numerical aperture) and Θ (acceptance angle).
- Apparatus: Typical test systems include a stable optical radiation source, collimation optics, aperture limiting, sample holder, imaging optics, image sensor and interference analysis equipment.
- Source quality: Incident wavefront on the test equipment shall have an rms deviation ≤ λ/20 over the effective microlens aperture (wavelength λ of the test source).
- Measurement arrangements: Separate arrangements are described for single microlenses and full microlens arrays, plus guidance on geometrical alignment and sample preparation.
- Test methods: Informative annexes describe specific implementations:
- Mach–Zehnder and Twyman–Green interferometer methods
- Lateral shearing interferometer methods
- Shack–Hartmann sensor method
- Procedures for array uniformity measurement
- Evaluation and reporting: Procedures for calculating P‑V and rms wavefront values, uncertainty of measurement, and required information in the test report are specified.
Applications and who should use it
- Practical uses:
- Quality control and production testing of microlens arrays
- R&D characterization of microlens shape and optical performance
- Acceptance testing for components in imaging devices, 3D displays, coupling optics, and arrayed light sources/detectors
- Intended users:
- Optical engineers and metrology laboratories
- Manufacturers of microlens arrays and integrated photonic modules
- Test houses performing interferometric and Shack‑Hartmann measurements
- Standards and compliance professionals in optics and photonics
Related standards
Keywords: microlens arrays, wavefront aberrations, microlens testing, interferometer, Shack‑Hartmann, optical testing standard, EN ISO 14880-2.
