Ultralow-loss germano-silicate PIC platform breaks short-wavelength barrier
Researchers have demonstrated a CMOS-compatible germano-silicate photonic integrated circuit (PIC) platform achieving record-low optical losses from the violet to the telecom bands, marking a significant advance for integrated photonics at short wavelengths.
Reported in Nature, the platform adapts germanium-doped silica, a material widely used in optical fibres, for planar photonic circuits using standard foundry processes.
The researchers achieved propagation losses as low as 0.08 dB m⁻¹ at 1,064 nm, corresponding to quality factors above 460 million, and 0.49 dB m⁻¹ at 458 nm, delivering a 13 dB improvement over previous records in the visible spectrum.
The fabrication process combines low-temperature PECVD deposition, deep-ultraviolet lithography, and CMOS-compatible etching, addressing long-standing challenges in integrating silica-based materials on chip.
Optional cladding configurations enable both optical and acoustic confinement, supporting functions such as soliton microcomb generation, stimulated Brillouin lasing, and self-injection locking of semiconductor lasers.
The platform also demonstrates strong noise performance, enabling Hz-level laser linewidths in both near-infrared and visible wavelengths.
By achieving fibre-like losses on chip without high-temperature post-processing, the germano-silicate PIC platform broadens the design space for quantum technologies, precision sensing, optical clocks, and advanced photonic systems.
