New research discusses conventional optical microscopes’ limitations and dielectric microspheres’ potential to overcome these limitations. It describes a novel 3D micro-device fabricated using femtosecond laser ablation and multi-photon lithography. This device integrates a modified coverslip and a microsphere to achieve enhanced resolution.
Conventional optical microscopes are limited by diffraction, which restricts their ability to resolve features smaller than the wavelength of light. This limit also limits the ability to study biological samples in detail, as many important cellular structures are smaller than the diffraction limit.
Dielectric micro-spheres hold immense promise in overcoming the limitations of diffraction. When light interacts with a dielectric micro-sphere, it can be focused on a spot smaller than the wavelength of light, a phenomenon known as superfocusing.
The research describes a novel 3D micro-device that integrates a modified coverslip and a dielectric microsphere. The modified coverslip is patterned with microstructures that collimate the incident light. The microsphere then focuses the collimated light to a subwavelength spot.
The performance of the 3D micro-device was evaluated using Mirau-type coherence scanning interferometry, a technique used to measure the axial resolution of the microscope. The results showed that the 3D micro-device significantly improved the axial resolution compared to a conventional optical microscope.
The researchers conclude that this 3D micro-device represents a significant breakthrough in optical microscopy. It can revolutionize the study of biological samples, enabling a level of detail never before possible.
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