Ultra-Wide-Bandwidth Edge Coupler With Large Mode Spot Size on Thin-Film LiTaO 3

Authors:
Publisher website
Google Scholar
Abstract
Thin-film lithium tantalate (TFLT) is an emerging electro-optic material with properties comparable to lithium niobate and promising applications in communications, sensing, and computing. With advances in wafer fabrication and low-loss dry-etched waveguides, TFLT has gained increasing attention. However, efficient fiber-to-chip coupling remains critical, especially for large-NA fibers that complicate mode conversion. Here, we demonstrate a TFLT large-mode-size edge coupler fabricated by standard semiconductor processes. Coupling to a high-NA fiber (MFD ∼6.5 μm) exhibits losses below 0.5 dB/facet in the O-band, below 0.37 dB/facet in the C-band, and 0.22 dB/facet at 1482 nm. The coupler maintains <1.3 dB/facet across 1200–2400 nm, with high misalignment tolerance and power stability.
Funding Information
  • Key Technology Research and Development Program of Shandong Province of China (2023CXGC010110)
  • National Natural Science Foundation of China (62175079)
  • National Natural Science Foundation of China (62205119)
  • Natural Science Foundation of Hubei Province of China (2020CFA004)

This publication has 56 references indexed in Scilit: