Fig. 3: Visual adaption of the 2D MIR optoelectronic retina for MIR targets with different optical power.
From: A two-dimensional mid-infrared optoelectronic retina enabling simultaneous perception and encoding
a Schematic diagram of test setup for the optoelectronic retina to perceive and encode the MIR targets. A 2D-moveable metal mask provides nine “3”-shaped MIR targets whose average optical power density (PMIR) are linearly distributed within 0 to 80.21 W/cm2 by adjusting the output optical power of 4.6 μm laser. b The directly detected images of nine MIR targets “3”, namely (i) to (x) in order. The color distribution is linearly mapped to PMIR. c The encoded images of nine MIR targets, whose color distribution is linearly mapped to spike rate ranging from 0 to 100 kHz. The rate of every pixel is calculated based on the spike train with 100 time-steps under u, σ, ITC of 130 mW/cm2, 75 mW/cm2, 0 nA, respectively. d Experimental result of spike rate as a function of PMIR for different u and σ used for sampling 730 nm light. e Results of encoding images under different u and σ. Such parameter adjustment allows device have flexible dynamic working range and encoding precision to adapt targets with different PMIR. f The correlation coefficient between each encoded target “3” in (e) and their original image in (b). A higher correlation coefficient indicates higher encoding precision. Four encoding cases with different (u, σ) are discussed.
