Full-color video and still imaging using two flat lenses.

Area of Science:

• Optics and Photonics
• Imaging Systems
• Materials Science

Background:

• Imaging systems typically require multiple lenses for focus, magnification, and sensor matching.
• Diffractive lenses offer potential advantages in miniaturization and fabrication compared to traditional refractive optics.

Purpose of the Study:

• To demonstrate the efficacy of using two millimeter-scale planar diffractive lenses in tandem for visible spectrum imaging.
• To explore the potential for low-cost, lightweight broadband camera applications.

Main Methods:

• Design, fabrication, and characterization of individual planar diffractive lenses with a 25mm focal length and NA = 0.05.
• Assembly of two diffractive lenses with a conventional color CMOS image sensor.
• Testing imaging performance under various illumination conditions (sunlight, halogen, LED).

Main Results:

• Successful demonstration of video and still imaging using the tandem diffractive lens system across the full visible spectrum.
• The system operated effectively under diverse lighting conditions.
• Diffractive lenses proved easier to fabricate than metalenses.

Conclusions:

• Tandem diffractive lenses are a viable solution for broadband visible imaging.
• This technology facilitates the development of cost-effective, lightweight cameras.
• The fabrication simplicity of diffractive lenses supports scalable manufacturing for future imaging devices.