This Circuit can compare the Light level in an area. It uses a PN Photodiode as the light sensor and IC CA3140 as voltage comparator. The circuit is ideal as the front end of burglar alarm circuits.

The newly developed waveguide photodiode can be incorporated into various types of programmable photonic devices to measure the intensity of light travelling in the waveguide, with accuracy ...

UV (ultraviolet) sensors of all sorts have been an interest of mine. They become interesting when you find the diversity of real-world practical applications. While searching for affordable UV light ...

Prof. Andrew POON (left), Head and Professor of the Department of Electronic and Computer Engineering at HKUST, and PhD student NIU Yue (right) at the Photonic Device Laboratory. Programmable ...