Integrated optical circuits are devices that integrate multiple photonic functions. It is similar to the electronic integrated circuit. These circuits provide functionality for data transfer on optical wavelengths in the spectrum of 850 to 1650 nm.
The advantage of these circuits is that they enable creation of high-performance and compact optical systems as compared to the application of separate optical components. Improved functionality could be achieved by integrating them with electronic circuits.
Indium phosphide is the most commonly used material for making integrated optical circuits. It enables the integration of different optically dynamic and non-active functions on the same processor. All the new monolithic tunable lasers, modulated transmitters and lasers, widely tunable lasers and integrated receivers are the perfect examples of integrated optic circuits.
The latest devices integrate large number of function on the same chip. Some of the leading centers of research in the technology include the Bell Laboratories, the University of California, and the Eindhoven University of Technology.
The technology was widely applied in fiber optic communication, but it has now been used in other fields like photonic computing and biomedical sciences. The latest application of the circuits in fiber optic communication is in the form of the externally modulated laser. It works by combining a laser diode and electro-absorption modulator on the same chip.
Another new innovation in the field is the creation of a type of bandpass plasmonic filter that achieves multichannel filtering. It offers easier control over filtering bandwidths and wavelengths in applications involving optical computing.
The currently used optic circuits are mostly based on Indium Phosphide, especially in the optical fiber communications field. Gradually silicon photonics is also gathering a lot of interest. In this new technology optic functionality is implemented directly onto silicon chips.