The transition from electronic integrated circuits to faster, more energy-efficient and interference-free optical circuits is one of the most important goals in the development of photon technologies. Photonic integrated circuits (PICs) are already used today for transmitting and processing signals in optical networks and communication systems, including, for example, I/O multiplexers of optical signals and microchips with an integrated semiconductor laser, a modulator and a light amplifier. However, today PICs are mostly used in combination with electronic circuits, while purely photonic devices are not yet competitive.