A doublet microlens array for imaging micron-sized objects

Area of Science:

• Optics and Photonics
• Microfabrication
• Nanotechnology

Background:

• Micron-sized object imaging requires advanced optical solutions.
• Existing miniaturized optical modules are often expensive and lack integration capabilities.

Purpose of the Study:

• To develop a high-numerical aperture, doublet microlens array for imaging micron-sized objects.
• To create an inexpensive and miniaturized optical module for integration with microfluidic and photonic devices.

Main Methods:

• Fabrication of a silicon microhole array using standard microfabrication processes.
• Novel fluidic assembly of glass microspheres on the microhole array.
• Covering the microspheres with a thin polymer layer to form doublet microlenses.
• Achieved an array of 56 micrometer diameter microlenses with a numerical aperture of approximately 0.5.

Main Results:

• Demonstrated brightfield and fluorescent image formation of micron-sized objects.
• Direct imaging onto a CCD sensor without intermediate lenses.
• Successful integration of microlenses with microfluidic devices is feasible.

Conclusions:

• The proposed doublet microlens array technology is a significant advancement for miniaturized optical modules.
• Offers a cost-effective solution for high-end imaging and detection applications.
• Enables integration with lab-on-chip and photonic chips for diverse applications.