Electro-optically tunable single-frequency lasing from neodymium-doped lithium niobate microresonators

Abstract

Tunable light sources are a key enabling technology for many applications such as ranging, spectroscopy, optical coherence tomography, digital imaging and interferometry. For miniaturized laser devices, whispering gallery resonator lasers are a well-suited platform, offering low thresholds and small linewidths, however, many realizations suffer from the lack of reliable tuning. Rare-earth ion-doped lithium niobate offers a way to solve this issue. Here we present a single-frequency laser based on a neodymium-doped lithium niobate whispering gallery mode resonator that is tuned via the linear electro-optic effect. Using a special geometry, we suppress higher-order transverse modes and hence ensure single-mode operation. With an applied voltage of just $68$V, we achieve a tuning range of $3.5$GHz. The lasing frequency can also be modulated with a triangular control signal. The freely running system provides a frequency and power stability of better than $\Delta \nu =20$MHz and 6%, respectively, for a 30 minute period. This concept is suitable for full integration with existing photonic platforms based on lithium niobate.

18 pages, 5 figures

References in corpus (7)

• Integrated photonics on thin-film lithium niobate
• High-performance Coherent Optical Modulators based on Thin-film Lithium Niobate Platform
• Integrated Pockels Laser
• An on-chip tunable micro-disk laser fabricated on Er3+ doped lithium niobate on insulator (LNOI)
• Whispering Gallery Mode Resonator Stabilized Narrow Linewidth Fiber Loop Laser
• An electro-optically tunable microring laser monolithically integrated on lithium niobate on insulator
• Ultra-low Threshold Titanium doped sapphire Whispering-gallery Laser

Cited by in corpus (3)

• Integrated Pockels Laser
• On-chip single-mode thin film lithium niobate laser based on Sagnac loop reflectors
• Polarization-entangled photons from a whispering gallery resonator