LioniX Develops A Near-Infrared Ultra-Narrow Linewidth Tunable Laser

LioniX International, a provider of integrated photonics and custom MEMS device solutions, has recently developed an ultra-narrow linewidth tunable laser on a chip that addresses the narrower range of near-infrared light, in collaboration with alliance partners in the REAP project. It is described as having a linewidth of 22 kHz, a tuning range of 45 nm, an output power of 5 dBm and an SMSR of -40 dB.
Hybrid integration of external cavity vernier lasers
This laser also looks simple: a semiconductor optical amplifier is connected to a TriPleX® chip that feeds directly into the fiber array. The laser power comes from a clever integrated circuit that includes a vernier filter (vernier filter) and two tunable micro-ring resonators implemented on their platform, and also includes a Mach-Zendel interferometer for tuning the output coupling efficiency.
To ensure thermal stability for long-term use, the laser is set up with a negative temperature coefficient thermistor mounted on a photonic integrated circuit and a thermoelectric cooler placed in a 14-pin butterfly package. Thermal management, as well as wavelength and output tuning, is electronically tuned with one of their internal laser controllers, developed for use with external cavity lasers.
Fast tuning over a wide range
At a center wavelength of 800 nm, the device has a maximum output power of 5 dBm and a minimum side mode rejection ratio of -40 dB. After testing its operation for over a full day, this laser output shows minimal drift and a constant package temperature of 25°C. The measured light has an intrinsic linewidth of 22 kHz and a tuning speed of sub-kHz.
The circuit was fabricated using its 850 nm MPW service, using a transverse waveguide cone to precisely connect the chip to the gain section and the output fiber. The optical loss at these interfaces can be as low as 0.3 dB at the gain side and 0.4 dB at the fiber side. their TriPleX® platform also supports vertical waveguide cones, but this is not used in this prototype.