3  ×  3 optical switch by exploiting vortex beam emitters based on silicon microrings with superimposed gratings

Abstract

A silicon-on-insulator microring with three superimposed gratings is proposed and characterized as a device enabling 3×3 optical switching based on orbital angular momentum and wavelength as switching domains. Measurements show penalties with respect to the back-to-back of <1 dB at a bit error rate of 10 for OOK traffic up to 20 Gbaud. Different switch configuration cases are implemented, with measured power penalty variations of less than 0.5 dB at bit error rates of 10. An analysis is also carried out to highlight the dependence of the number of switch ports on the design parameters of the multigrating microring.

Recent Advances in Generation and Detection of Orbital Angular Momentum Optical Beams—A Review

“…Figure 10c shows a SEM image of the first-order SPP that will be inserted into the circular aperture in the Cr/Au layer of the MEMS DBR. Notwithstanding that most of the proposed methods are experimentally verified, telecom applications are demonstrated only for ring resonators with annular grating [61,148,150], fixed SPPs [65,159,160], and lately for a pixel-array structure [154]. The output OAM beam from most out-of-plane generation methods is satisfactory in terms of mode purity; nevertheless, free-space propagation necessitates the use of a lens to concentrate the signal and couple it into the optical fiber, which reduces the final device's reliability and scale.…”

“…A variable amplitude splitter and an OAM emitter based on a μ-ring cavity are presented in [ 62 ]. Another research [ 150 ] employs a silicon-on-insulator μ-ring with three superimposed gratings, each designed to emit a different OAM order, as a device enabling 3 × 3 optical switching. This approach utilizing the ring resonators with gratings provides good mode purity for OAM-multiplexing, however, the OAM-beams are generated already out of the chip plane in free space and cannot be used or processed at the chip any more.…”

Modeling and Optimization of Vortex Modes Propagation in Rectangular Dielectric Waveguides

“…Main design solutions for out-of-plane vortex beam emitters include but are not limited to i) VCSEL integrated with micro spiral phase plate [31], ii) annular grating or a set of annularly placed gratings [32]- [36], and iii) ring resonator with azimuthally distributed light-emitting grating [37]- [44]. The last approach has shown robustness, potential for wavelength and OAM tunability, and high purity of the generated OAM states, allowing OAM-multiplexed transmission [40]- [43]. The weak point of this approach is its limited multiplexing scalability, as well as the need of a free space element (lens) to couple the generated beam.…”