Bifocal flat lens with different imaging characteristics for a dual-sensor imaging system.

Area of Science:

• Optics and Photonics
• Materials Science
• Imaging Technology

Background:

• Dual-sensor imaging systems capture wide field-of-view (FOV) and magnified images simultaneously.
• Current systems often require bulky and complex setups.
• Miniaturization and integration are key challenges in advanced imaging.

Purpose of the Study:

• To propose and develop a bifocal flat lens for integrated and miniaturized dual-sensor imaging systems.
• To achieve two distinct focal characteristics from a single, thin optical element.
• To enhance imaging capabilities for simultaneous wide FOV and high-resolution capture.

Main Methods:

• A bifocal diffractive lens (BDL) was designed by combining specific elements from conventional zone plates (ZP).
• The BDL was fabricated with a thickness of 0.6 μm and a diameter of 6 mm.
• Experimental validation was performed to assess the imaging performance of both focal points.

Main Results:

• The developed BDL exhibits two foci: a long focus (~81 mm) for high-resolution magnified imaging (resolution up to 21.90″) and a short focus (~27 mm) for wide FOV imaging with a long depth of focus (DOF).
• Objects separated by 2880 mm were clearly imaged using the short focus.
• Experimental results surpassed the performance metrics of conventional refractive lenses.

Conclusions:

• The proposed bifocal flat lens enables integrated and miniaturized dual-sensor imaging.
• The BDL provides simultaneous wide FOV and high-resolution imaging capabilities.
• This technology offers superior performance compared to conventional lenses for dual-imaging applications.