Titanium:sapphire-on-insulator integrated lasers and amplifiers.

ABSTRACT

Titaniumsapphire (Tisapphire) lasers have been essential for advancing fundamental research and technological applications, including the development of the optical frequency comb1, two-photon microscopy2 and experimental quantum optics3,4. Tisapphire lasers are unmatched in bandwidth and tuning range, yet their use is restricted because of their large size, cost and need for high optical pump powers5. Here we demonstrate a monocrystalline titaniumsapphire-on-insulator (TiSaOI) photonics platform that enables dramatic miniaturization, cost reduction and scalability of Tisapphire technology. First, through the fabrication of low-loss whispering-gallery-mode resonators, we realize a Tisapphire laser operating with an ultralow, sub-milliwatt lasing threshold. Then, through orders-of-magnitude improvement in mode confinement in TiSaOI waveguides, we realize an integrated solid-state (that is, non-semiconductor) optical amplifier operating below 1 µm. We demonstrate unprecedented distortion-free amplification of picosecond pulses to peak powers reaching 1.0 kW. Finally, we demonstrate a tunable integrated Tisapphire laser, which can be pumped with low-cost, miniature, off-the-shelf green laser diodes. This opens the doors to new modalities of Tisapphire lasers, such as massively scalable Tisapphire laser-array systems for several applications. As a proof-of-concept demonstration, we use a TiSaOI laser array as the sole optical control for a cavity quantum electrodynamics experiment with artificial atoms in silicon carbide6. This work is a key step towards the democratization of Tisapphire technology through a three-orders-of-magnitude reduction in cost and footprint and introduces solid-state broadband amplification of sub-micron wavelength light.