High-Speed Optical Mode Switch in Lithium Niobate on Insulator

Abstract

Mode-division-multiplexing technology is highly attractive to increase the capacity of optical interconnects. Various multimode operations have been investigated, among which optical mode switches provide one of the most important functions in mode-division-multiplexing systems. However, current optical mode switches have a non-negligible switching time, which can lead to an undesired cumulative delay in the optical network. In this contribution, we propose and experimentally demonstrate an optical mode switch using a three-waveguide-coupling structure in the lithium niobate on insulator platform. The demonstrated optical mode switch has an insertion loss of 4.3 dB, an extinction ratio of 17.1 dB, and a switching time of below 28 ps. This work paves the way for future chip-scale highspeed mode-division-multiplexing systems.

A Compact Mode Controller (Switch) Using an Inverse-Designed 2-Mode Y-Junction

“…Of interest in this work is active mode conversion or switching, i.e., the controlled transformation between different modes in the waveguides. This type of integrated optical mode modulator has been demonstrated in Lithium Niobate [9] with modulation speeds > 40 GHz (tested only at 1 GHz) and in Silicon [10], [11] using multimode interferometer (MMI) couplers, achieving a data rate > 30 GBaud. All systems occupy, however, a large silicon area, a significant part of which is dedicated to passive mode conversion.…”

PLC-Based Polymer/Silica Hybrid Inverted Ridge LP11 Mode Rotator

“…Integrated optics, compatible with large-volume and low-cost complementary metal oxide semiconductor (CMOS) technology, is a method to realize compact and complex on-chip systems. Currently, MDM components, including mode-division multiplexer/demultiplexer (MUX/DeMUX) [ 5 , 6 , 7 , 8 ], mode-selective switch [ 9 , 10 , 11 ], and multimode spirals [ 12 , 13 ], have been proposed and applied in reconfigurable optical networks [ 14 , 15 ], optical computation [ 16 ], and nonlinear optics. However, traditional waveguides are co-planar (or 2D) structures that impose significant limitations on the design of (de-)multiplexers with a three-dimensional (3D) spatial distribution of fiber modes [ 17 ].…”

Programmable Optical Filter in Thin-Film Lithium Niobate with Simultaneous Tunability of Extinction Ratio and Wavelength

“…While LN devices have been widely adopted for telecommunication and RF signal processing in the past decades, the large optical mode size and weak optical confinement in LN waveguides prevent its further development in integrated nanophononics. Recently, thin-film LN (TFLN) has emerged as a promising platform for high-performance photonic devices. – The TFLN devices have submicron waveguide with high refractive index contrast and small mode size, which largely decrease the electrode length and microwave losses, thereby breaking the fundamental bandwidth limit in bulk LN devices. – High-performance TFLN modulators with low operating voltages, ultrahigh working bandwidths, and compact footprints have been widely reported. – Moreover, a ring-loaded MZI modulator in TFLN has presented the breakthrough of the bandwidth limit in a high quality factor ( Q ) ring with coupling modulation, , which is a significant improvement for future high-density integration in a TFLN platform. However, simultaneous and independent control of the extinction ratio and wavelength in TFLN is yet to be demonstrated.…”