Fig. 4: The dynamic response and the life cycle of the VO2 cavities.
From: Durable and programmable ultrafast nanophotonic matrix of spectral pixels
a, Dynamic response as a function of varying modulation frequency. Panels i–iii are zoomed-in views of the areas labelled in the main panel and show the responses for 1 kHz, 5 kHz and 70 kHz modulated input signals, respectively. b, The durability of our device for one million cycling times. The device is irradiated with a 532 nm laser while an on–off electrical signal is applied to an ITO microheater. A photodetector is used to monitor the reflected light. The vertical label shows the voltage output at voltages around 3 V and 1 V (of an oscilloscope connected to the photodetector) when the electrical signal is on and off, respectively. The shaded areas indicate the variations of the outputs. c, The reflectance before and after one million times of switching. d, The appearance before and after one million times of switching. The colour difference ΔE is less than 0.65 before and after one million times of switching. Scale bar, 20 µm.
