Blue GaN-based DFB laser diode with sub-MHz linewidth.

Distributed feedback laser diodes (DFBs) serve as simple, compact, narrow-band light sources supporting a wide range of photonic applications. Typical linewidths are on the order of sub-MHz for free-running III-V DFBs at infrared wavelengths, but linewidths of short-wavelength GaN-based DFBs are considerably worse or unreported. Here, we present a free-running InGaN DFB operating at 443 nm with an intrinsic linewidth of 685 kHz at a continuous wave output power of 40 mW.

Investigation of Q degradation in low-loss SiN from heterogeneous laser integration.

High-performance, high-volume-manufacturing SiN photonics requires extremely low waveguide losses augmented with heterogeneously integrated lasers for applications beyond traditional markets of high-capacity interconnects. State-of-the-art quality factors (Q) over 200 million at 1550 nm have been shown previously; however, maintaining high Qs throughout laser fabrication has not been shown. Here, SiN resonator intrinsic Qs over 100 million are demonstrated on a fully integrated heterogeneous laser platform.

Heterogeneous quantum dot lasers on low-confinement silicon nitride with reduced-bending architecture.

Low-confinement silicon nitride (SiN) waveguides offer ultra-low losses but require wide bend radii to avoid radiative losses. To realize the benefits of silicon nitride in a heterogeneous laser while maintaining a small footprint, we employ metal-coated etched facets and transversely coupled Fabry-Perot resonators as mirrors. Heterogeneous quantum dot lasers are fabricated using an on-chip facet plus adiabatic taper coupler, and Fabry-Perot cavities are defined by metal mirrors and post-grating-distributed Bragg reflectors (DBRs).

Coprocessed heterogeneous near-infrared lasers on thin-film lithium niobate.

Thin-film lithium niobate (TFLN) is an attractive platform for photonic applications on account of its wide bandgap, its large electro-optic coefficient, and its large nonlinearity. Since these characteristics are used in systems that require a coherent light source, size, weight, power, and cost can be reduced and reliability enhanced by combining TFLN processing and heterogeneous laser fabrication. Here, we report the fabrication of laser devices on a TFLN wafer and also the coprocessing of five different GaAs-based III-V epitaxial structures, including InGaAs quantum wells and InAs quantum dots.

Extending the spectrum of fully integrated photonics to submicrometre wavelengths.

Integrated photonics has profoundly affected a wide range of technologies underpinning modern society. The ability to fabricate a complete optical system on a chip offers unrivalled scalability, weight, cost and power efficiency. Over the last decade, the progression from pure III-V materials platforms to silicon photonics has significantly broadened the scope of integrated photonics, by combining integrated lasers with the high-volume, advanced fabrication capabilities of the commercial electronics industry.

Integrated Pockels laser.

The development of integrated semiconductor lasers has miniaturized traditional bulky laser systems, enabling a wide range of photonic applications. A progression from pure III-V based lasers to III-V/external cavity structures has harnessed low-loss waveguides in different material systems, leading to significant improvements in laser coherence and stability. Despite these successes, however, key functions remain absent.