The need for miniaturized, fully integrated semiconductor lasers has stimulated significant research efforts into realizing unconventional configurations that can meet the performance requirements of a large spectrum of applications, ranging from communication systems to sensing. We demonstrate a hybrid, silicon photonics-compatible photonic crystal (PhC) laser architecture that can be used to implement cost-effective, high-capacity light sources, with high side-mode suppression ratio and milliwatt output output powers. The emitted wavelength is set and controlled by a silicon PhC cavity-based reflective filter with the gain provided by a III–V-based reflective semiconductor optical amplifier (RSOA). The high power density in the laser cavity results in a significant enhancement of the nonlinear absorption in silicon in the high Q-factor PhC resonator. The heat generated in this manner creates a tuning effect in the wavelength-selective element, which can be used to offset external temperature fluctuations without the use of active cooling. Our approach is fully compatible with existing fabrication and integration technologies, providing a practical route to integrated lasing in wavelength-sensitive schemes.
In this paper, we show the experimental results of a thermally stable SiN external cavity (SiN EC) laser with high power output and the lowest SiN EC laser threshold to our knowledge. The device consists of a 250 μm sized reflective semiconductor optical amplifier butt-coupled to a passive chip based on a series of SiN Bragg gratings acting as narrow reflectors. A threshold of 12 mA has been achieved, with a typical side-mode suppression ratio of 45 dB and measured power output higher than 3 mW. Furthermore, we achieved a mode-hop free-lasing regime in the range of 15-62 mA and wavelength thermal stability up to 80°C. This solves the challenges related to cavity resonances' thermal shift and shows the possibility for this device to be integrated in dense wavelength-division multiplexing (WDM) and heat-intensive optical interconnects technologies.
We explore the short-cavity hybrid laser consisting of a III-V amplifier integrated with a silicon photonic crystal (PhC) cavity reflector using the so-called butt-coupling approach. The laser possesses great stability characteristics meeting the criteria for data center interconnect applications. The PhC reflector having a Q-factor of 10 4 at a lasing wavelength 1535 nm can be considered as a narrow-bandwidth filter. The laser demonstrates single mode and eventless operation without any dynamics on the background, and featureless radiofrequency spectrum without evidence of relaxation oscillation frequency. We confirm our experimental observations by theory based on a delay differential equation model for a single-section semiconductor laser. We reveal the effective damping of the laser, when the detuning between the filter peak and the laser cavity mode is small, and the imaginary parts of the model eigenvalues equal zero. Undamping of the relaxation oscillations is also possible forcing self-Q-switched operation in the laser owing to the cumulative action of the alpha-factor and the narrow filter.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.