Compact microoptical imaging system (ultra-thin microscope)

Ambition

Digital close-up imaging of extended object fields with high resolution using a compact optical system setup.

Characteristics

• Optical setup using three double-sided microlensarray modules on a digital image sensor
• Multichannel imaging with partial image stitching
• Aspherical and achromatic lenslets
• Unity magnification
• Object-to-image distance 5.3 mm
• Numerical aperture 0.1
• Object field size 36 mm x 24 mm (scalable with image sensor size)
• Resolution up to 4 μm

Application

• Inspection of surfaces, print materials
• Bio-/ medical imaging
• Document analysis
• Digitalization of photographic film material

Technology

• Wafer-scale process on thin glass substrates
• Master generation using lithography and resist reflow
• Proportional transfer by dry etching (RIE, ICP) for aspherical lenslets
• Double-sided, aligned UV-molding
• UV-structuring of absorbing polymer diaphragm arrays
• Module assembly using alignment marks
• AR-coating of surfaces
• Dicing with chip saw