Design and development of a single-material high-throughput objective for ultraviolet-visible imaging

High-throughput microscopic imaging is essential for applications such as gene sequencing and semiconductor inspection. The requirements for high numerical aperture (NA) and ultraviolet broadband performance introduce substantial challenges in controlling spherical aberration and chromatic aberration. To address these challenges, this study proposes and fabricates a single-material high-throughput catadioptric objective that offers high NA, a wide field of view (FOV), and a wide wavelength range. Through ray tracing and numerical analysis, conditions for aberration correction and apochromatism are derived, and a computational model for the initial structure of this catadioptric objective is established. Based on this model, a broadband objective (0.360-0.600 µm, 0.9 NA, 5.0 mm focal length, and 1.0 mm FOV) is designed, and only fused silica is used. An objective prototype is developed and tested. The results show that the root mean square (RMS) of the wavefront error is below 0.068λ at 0.365 µm test wavelength across the whole FOV. The objective achieves a high resolution of 3300 lp/mm, field curvature less than 150 nm, and relative distortion below 0.08%. Chromatic aberration is effectively controlled, and imaging quality approaches the diffraction limit. These results confirm the validity of the proposed aberration correction conditions and the initial-structure model. This work establishes a systematic technical approach for developing high-NA, broadband, and non-immersion microscope objectives.