Photon Design, a global leader in photonic simulation CAD software, has developed a template design for narrow linewidth, tuneable lasers, with cascaded Mach Zehnder Interferometer (MZI) filters. The universal design has been made available for users of its PICWave simulation tool to simply adapt for their own applications. This reduces valuable design time for customers and accelerates NPI.

The tuneable laser’s ultra narrow linewidth is produced by a cavity of three, cascaded, tuneable, MZI filters connected in series, each with a unique spectral response. Every MZI has a phase modulator where PICWave simulates the effect of voltage, enabling users to tune MZI imbalances and generate the lasing wavelength. When combined, these create an increasingly finer wavelength and ultimately produce the laser’s narrow linewidth. A fourth phase modulator enables the effective optical path length of the entire laser cavity to be tuned, at the same rate as the MZI’s, preventing mode hopping over a large tuning range and avoiding discontinuities in output power.

Dr. Dominic Gallagher, CEO of Photon Design, said, “Photon Design’s tuneable, laser is configured to operate without mode hopping over a 60nm tuning range. The laser’s spectral response is simulated by PICWave, including how it evolves over time with multiple tuning voltages. We provide instructions on how PICWave users can customise and calibrate the laser for their own epitaxy requirements.

“PICWave originated as a laser diode simulator and includes many advanced physical effects essential for modelling cutting-edge lasers. This includes optical mode propagation, thermal effects, carrier diffusion, and how their combined coupling impact laser gain. Despite this level of capability, a standard desktop computer can perform PICWave’s complex, 3D, time-evolving simulation in just a few minutes; even for lasers measuring many millimetres in length.”