Optical rotary encoder is an electro-mechanical device used to convert the angular position of a shaft or axle to an analog or digital code, making it a sort of transducer. This device is used in robotics, in top-of-the-line photographic lenses, in computer input devices, and in rotating radar platforms.

Optical sensors are designed to continuously monitor liquid level in petroleum and chemical industries. The sensor is composed of a sensing diaphragm with a hard center, a microbend modulator (a pair of tooth plates), sensing and reference fibers, adjusting bolts, a stainless steel housing, emitting/detecting devices and signal processing circuits. Numerous types of sensors with various principles are used for liquid level measurement of oil tanks.

Optical Switch is a switch that enables signals in optical fibers or integrated optical circuits to be selectively switched from one circuit to another. An optical switch operates by mechanical means, such as physically shifting an optical fiber to drive one or more alternative fibers or by electro-optic effects and magneto-optic effects.