An optoelectronic chip with integrated epi-illumination source and collection optics for imaging applications

Abstract

The increasing demand for miniaturized, portable and low-cost imaging systems has led to the development of compact, optical components that integrate multiple functions and have short optical paths. We describe a novel opto-electronic chip for imaging opaque or semi-transparent samples in epi-illumination mode. The chip integrates of an array of ball lenses – 1 mm in diameter – and ring-shape Light Emitting Diodes (LEDs). A sample, when placed at closed proximity to the chip (<300 μm), is illuminated by the LEDs, and the reflected light is collected by the lenses and focused onto a detector. The proposed architecture separates the excitation and emission optical paths and enables epi-illumination imaging without the need of using bulky and complex optical components. With an optical resolution of 8.8 μm and a total optical path of less than 2.5 mm, we believe that the developed chip is an ideal module for compact portable, reflection-based imaging systems.