High-power sub-kHz linewidth lasers fully integrated on silicon

Abstract

We demonstrate a fully integrated extended distributed Bragg reflector (DBR) laser with ∼1 kHz linewidth and over 37 mW output power, as well as a ring-assisted DBR laser with less than 500 Hz linewidth. The extended DBR lasers are fabricated by heterogeneously integrating III-V material on Si as a gain section plus a 15 mm long, low-kappa Bragg grating reflector in an ultralow-loss silicon waveguide. The low waveguide loss (0.16 dB/cm) and long Bragg grating with narrow bandwidth (2.9 GHz) are essential to reducing the laser linewidth while maintaining high output power and single-mode operation. The combination of narrow linewidth and high power enable its use in coherent communications, RF photonics, and optical sensing.

Ring resonator enhanced mode-hop-free wavelength tuning of an integrated extended-cavity laser

“…We expect that the demonstrated tuning method based on resonant intracavity filtering can be applied to other types of lasers as well. Possible examples are photonic crystal lasers [35,36], Bragg waveguides [37,38], other gain materials [39,40] or nonlinear gain. The expected advantages are linewidth narrowing without obstructing continuous tuning, increasing the tuning range without obstructing linewidth narrowing, and reduced power consumption or higher speed in continuous tuning or stabilization of single-frequency lasers.…”

Highly-Sensitive Phase and Frequency Noise Measurement Technique Using Bayesian Filtering

“…(3) based on direct demodulation [3], [4], 2) a self-homodye delay-interferometer, implemented in the OEwaves OE4000 laser linewidth and phase noise system and 3) the Bayesian filtering framework, implementing the UKF or EKF. The LUT is a fully integrated ultra-low noise laser with an output power of -2.3 dBm [7]. The LO is a Koshin Kogaku tunable laser with output power of 2 dBm.…”

Compact silicon photonic hybrid ring external cavity (SHREC)/InGaSb-AlGaAsSb wavelength-tunable laser diode operating from 1881-1947 nm

“…Hybrid/heterogenous [36] silicon photonic diode lasers enable additional degrees of freedom as compared to III -V lasers by combining the best of both worlds. SiPh offers low propagation loss and high integration densities while III -V material contributes high gain values [37] and the flexibility for bandgap engineering via changes in material composition [38], realizing high performance, novel light sources; examples are the high power, sub-kHz linewidth heterogenous silicon laser [39] as well as hybrid/heterogenous silicon lasers that operate in the spectroscopically imperative wavelength region above 2 µm [40]. Hybrid integration allows for III -V and silicon to be individually optimized, while the heterogenous approach enables compact footprint in addition to demonstrating potential for high-volume production [36].…”