Light polarization beam splitter

Abstract

The invention discloses a light polarization beam splitter. The light polarization beam splitter comprises an orientation coupler. The narrow waveguide of the orientation coupler receives an input light source and outputs TE0 light in the input light source, couples TM0 light in the input light source to wide waveguide and converts the TM0 light into TM1 light. The output end of the wide waveguide is connected with a first MMI coupler, and the first MMI coupler divides the input TM1 light into two beams of TM0 polarized light, wherein the two beams of TM0 polarized light are the same in power, and the phase difference of the two beams of TM0 polarized light is 180 degrees. The two output ends of the first MMI coupler are respectively connected with the input end of a second MMI coupler through a 90-degree phase shifter. One output end of the second MMI coupler serves as a TM0 polarized light output port. The equation of the length of the first MMI coupler is shown in the specification, and Lpi1 represents the beat length of the first MMI coupler. The second MMI coupler is an interference coupler. According to the light polarization beam splitter, a high-capacity monolithic integration chip can be achieved, and the light polarization beam splitter has the advantages that the bandwidth is very large, the extinction ratio is very high, and the loss is very low.

Description

technical field [0001] The invention relates to the fields of optical communication, optical interconnection and optical device integration, specifically, an optical polarization beam splitter based on the combination of a directional coupler, a phase shifter and an MMI coupler. Background technique [0002] In future optical interconnection and optical communication chips, optoelectronic integrated circuits (PICs) with high capacity, compact size and low cost will become people's first choice. There are currently several ways to increase capacity, among which the multiplexing of polarization modes is an effective solution. Polarization beam splitter, as an important device to achieve polarization multiplexing, has also become a research hotspot. [0003] Current multi-mode interference beam splitters, polarization beam splitters, and polarization beam splitters using multi-mode interference principles and common multiple principles are all relatively large in size. Some r...

AI Technical Summary

Problems solved by technology

Some reports use the principle of quasi-imaging to reduce the size, but quasi-imaging has an additional loss of 2dB due to its own imaging characteristics, and the bandwidth is not very large

The reported traditional symmetric directional coupler usually utilizes L=pL πTE =qL πTM , among them, L πTE and L πTM is the coupling length of TE and TM modes, p and q are integers satisfying p=q+m (m=±1,3,5…), in order to satisfy the above formula, the size of the waveguide needs to be strictly controlled, and the size of the device Relatively long, especially for weakly confining index waveguide materials

Recently reported polarizing beam splitters based on symmetrical directional couplers are relatively compact in size, but the extinction ratio is not very high

Images