Efficient Single-Pixel Batch Measurement Method for Optical Properties of Micro-Sized LED Array

The evaluation of single-pixel mini-/micro light-emitting diode (LED) optical properties among an array or module faces difficulties in total acquisition of weak signal at small driven current and avoiding optical crosstalk from the adjacent chips simultaneously. In this work, we propose an efficient single-pixel batch measurement method, which combines microscopic hyperspectral imaging (mu-HSI) and a silicon-based micro-integrating sphere array (mu-ISA). Truncated-inverted-pyramid micro cavities coated with gold reflective layer are designed and fabricated in the mu-ISA, which can effectively collect the total optical power of micro-sized LEDs and avoid optical crosstalk from the adjacent chips simultaneously. A 1-in integrating sphere and halogen lamp coupled by optical fiber are used as calibration light source. A two-step procedure is proposed to calibrate the absolute optical power distribution of the mu-HSI measurement method. Comparative studies on optical properties, including photometry and colorimetry, are carried out to demonstrate the advantages of the proposed method in accuracy, capabilities of avoiding optical crosstalk, and batch detection of micro sized LED (Micro-/Mini-LED) array.