Diode-pumped photonic integrated titanium-sapphire waveguide amplifier

Stanford researchers have developed ultra-wideband amplification of near infrared signals for the first time on a photonic integrated circuit. Previously, optical amplification on photonic integrated circuits has been limited to wavelengths longer than 1000 nm, which has restricted use in biological applications. Furthermore, tabletop titanium-sapphire are large, cost, and require high optical pump powers. The Stanford developed diode-pumped photonic integrated titanium-sapphire waveguide amplifier incorporates the critical near-infrared window for biological tissue, which is pivotal for medical imaging and diagnostic equipment, as well as provides an on-chip solution for applications such as quantum technology, LiDAR and beyond.

The device consists of a nanophotonic crystalline thin-film titanium-sapphire optical waveguide co-integrated with a semiconductor diode-laser used to pump the titanium-sapphire waveguide. The nanophotonic titanium sapphire waveguide amplifies optical signals with wavelength ranging from 700 nm to 1000 nm. The titanium-sapphire waveguides do not absorb when the material is not pumped, and passive propagation losses are smaller than 0.45 dB/cm. These titanium-sapphire waveguides outperform currently available optical gain waveguides, and meets the needs of a wide range of applications in photonic integrated circuits

Stage of Development – Proof of Concept Prototype