Design for Y-branch waveguides with wide angle and low loss

Abstract

A novel method to design Y-branch waveguides is proposed by using total internal reflection, and the optical properties are analyzed. The simulated results show that the optical loss values of two Y-branch waveguides with the branching angles of 12 o and 30 o are only 0.310 dB and 0.645 dB, respectively. Compared with conventional Y-branch waveguides, the optical performance of the proposed ones is well improved, which has many advantages such as wide angle, low loss, simple structure and easy for fabrication.

Novel Approach for Controllable Polarization Beam Splitter: Design and Simulation

“…However, the branching angle is generally small, and then it leads to rapid increase in the length of the device, which is difficult to achieve the compact structure. In our previous work, the optical power splitter based on total internal reflection has been investigated, which can effectively increase its branching angle [15], [16]. Therefore, the multisectional bends based on total internal reflection are employed in the proposed configuration, which not only obtains a relatively large branching angle, but also achieves good polarization splitting performance at the branching point, due to the large difference in propagation conditions for TE and TM modes.…”

“…When there is no applied voltage between the electrodes, the optical signal for TM mode at the branching point will be reflected to exit from output port A, due to the total internal reflection [15], [16], since the refractive index seen by the light is equal to n o in the liquid crystal area, smaller than n 2 . Whereas, the optical signal for TE mode at the branching point will be coupled into the straight waveguide, resulting from mode selecting effect [20], because the refractive index seen by the light is equal to n e in the liquid crystal area, larger than n 2 .…”

“…In the designed structure, the deflection angle θ is a critical parameter, which is described by the following formula [15], [16],…”

Design and analysis of a novel tunable optical power splitter

“…1, the tunable optical power splitter we propose is a novel component, in which a symmetric Y-branch waveguide is combined with three wedge electrodes in the tapered waveguide region. This Ybranch waveguide based on total internal reflection has a very low dependence on operation wavelength, wide angle, low optical loss, a compact structure, and ease of fabrication [8] , which is unique in tunable optical power splitters. Three wedge electrodes, as top electrodes, are introduced in the tapered waveguide region to produce two different microprisms with tunable refractive indices in their corresponding regions using the electro- optic effect.…”

“…The details of the fabrication have been reported by Thapliya et al [7] . In addition, the Ybranch waveguide has a relatively large fabrication tolerance, which has been analyzed in previously reported literatures [6,8] . Since the wedge electrodes were used as a microprism by applying the external voltage, their precise fabrication is imperative.…”