With a fan, a laser, and a sensitive photodetector, they can measure smoke and other particulates in real-time. Surprisingly, they are also fairly cheap, going for less than $20 USD on some import ...

Only here, it’s a laser rangefinder ... reflected spot through a lens on a linear image sensor (which renders as “photodetector line” in translated Russian). Linear image sensors are ...

Their study was published in Laser & Photonics Reviews ... an AlGaN-based DUV micro-LED array and zinc oxide (ZnO)-based ...