But do the LED masks actually work ... green, yellow, and white light wavelengths, depending on the price point of the mask. Red light, with a wavelength around 700 nanometers, penetrates deeper ...

LEDs emitting red light cannot be used for white-light generation using phosphors; instead a short-wavelength ultraviolet, violet or blue LED is required. Early attempts to produce blue-emitting ...

This work presents a single-shot full-color digital holographic camera that is portable by hand and operates with continuous-wavelength white-light illumination from an LED. Experimental results ...