In the optical fiber communication system, the optical switch (OS) is mainly used to realize the physical switching of optical signals or other logical operations in the optical path, and is mostly used in the optical cross-connect (OXC) technology as a key device for optical switching.

Optical switch is a multiport device. The port configurations include 2×2, 1×N, M×N. Optical switches have a wide range of applications in optical fiber communication systems. According to the realization technology can be classified as mechanical optical switch, thermo-optical switches, acoustic-optical switches, electro-optical switches, magneto-optical switches, liquid crystal optical switches and MEMS optical switches, etc. Mechanical optical switch and MEMS optical switch are the two widely used optical switches.

The working principle of the mechanical optical switch is to redirect the optical signal by physically moving the optical fiber with the aid of a mechanical device. By moving the prism or directional coupler, the light at the input end is directed to the desired output port. There are three main types of mechanical optical switches: one is to use prism to switch the optical path technology, the other is to use mirror switching technology, and the third is to switch the optical path by moving optical fibers.

Mechanical optical switch

The MEMS optical switch is based on a micro-electro-mechanical system, which uses an optical micro-mirror or an optical micro-mirror array to change the direction of the beam to switch the light path. The principle of the MEMS optical switch is very simple. When the light is exchanged, the angle of the MEMS micro mirror is moved or changed by the drive of electrostatic force or magnetic power, and the input light is switched to the different output terminals of the optical switch to realize the switching and on-off of the optical path. The schematic diagram is shown below:

The principle of mems optical switch

The principle of the 2×2 optical switch is shown in Fig. Four waveguides are aligned in four directions and a vertical MEMS mirror is aligned in 45° direction. When the mirror is not inserted into the optical path, optical beams from waveguides 1 and 2 are coupled to waveguides 3 and 4, respectively. The port connection is 1→3 & 2→4, which is the bar state. When the mirror is inserted into the optical path, optical beams from waveguides 1 and 2 are reflected by the mirror and then coupled to waveguides 4 and 3, respectively. The port connection is switched to 1→4 & 2→3, which is the cross state.

Principle of the 2×2 MEMS optical switch, left: bar state, right: cross state

MEMS optical switch

With the rapid development of optical communications, the status of optical interconnection and optical switching as optical network nodes is becoming more and more important, and the application of optical switches is becoming more and more extensive. MEMS optical switches have the advantages of compactness, fast switching speed, and easy expansion. At the same time, they have the low insertion loss, low crosstalk, low polarization sensitivity, high extinction ratio and high switching speed of waveguide switches, small size, and easy expansion of mechanical optical switches. The advantages of large-scale integration. It will be the mainstream direction of the development of high-capacity switching optical network switches.

HYC independently develops MEMS optical switch series products, with 1×2, 1×4, 1×N channel configuration, which can be expanded up to 1×48 channels, and has the advantages of low power consumption, integration, fast response speed, and cost reduction. Headquartered of HYC Co., Ltd is in Qingyuan Guangdong, and HYC has R&D centers in Wuhan and Shenzhen. It has more than 1,000 employees and has more than 20 years of OEM and ODM experience. It provides one-stop customization for the design, R&D and manufacturing of optical communication optical passive components.
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