Reduced PIC fabrication cost by one-step method

The new fabrication method is an electron lithography scheme enabling monolithic integration of multiple photonic devices on a single PIC. The technology was demonstrated by integrating both a widely-tunable distributed Bragg reflector (DBR) and distributed feedback (DFB) lasers on the same substrate. By controlling the central gap width and etch depth along the laser mirror length (shown in the figure below) the reflectivities can be tuned and the desired laser characteristics can be achieved without additional lithography cycles. Initially demonstrated on an indium phosphide substrate with DBR and DFB elements, the platform technology shows promise for various other materials and devices like III-V and II-VI semiconductors, silicon-on-insulator (SOI), and planar lightwave circuits (PLCs). With this versatility, the invention described here can streamline PIC production across diverse applications. Proof-of-concept results showcase the lithographic technique’s ability to produce high-performance photonic devices with side-mode suppression ratios over 50 dB (figure on the right) and output powers exceeding 5 mW. These metrics, combined with the lithographic simplicity, highlight the technology’s potential to reduce costs and accelerate PIC manufacturing. Please note that NASA does not manufacture products itself for commercial scale. Researchers at the NASA Goddard Space Center have developed an innovative technique that allows photonic integrated circuit (PIC) chips with multiple devices to be produced with only a single round of electron beam lithography and etching. Traditionally, fabricating PICs with different types of lasers or devices within the same area requires multiple costly and time-consuming lithography cycles. By introducing a central, non-etched gap along the length of the device between the etched gratings, at least two photonic devices can be fabricated during one lithography and etching cycle. The new geometry allows an engineer to design integrated devices with differing optical properties by varying the non-etched gap width and the etch depth. This innovative approach dramatically reduces manufacturing time and costs while maintaining performance with applications in PIC-based devices across the space, communication, autonomous vehicle, and biomedical industries.