The process involves choosing materials with desired properties, depositing and patterning them sequentially to create an integrated circuit. Electron beam lithography is a common fabrication technique used by researchers to produce unique structures and devices with nanometer precision. However, this method is time-consuming and is difficult to implement for large-scale production.
During his time as a postdoctoral fellow in Professor Jean-Michel Ménard’s lab, Mohammad Bashirpour developed a novel nanofabrication technique to pattern the surface of a gallium phosphide (GaP) semiconductor crystal. This material plays a key role in nonlinear optics for frequency conversion, the process allowing the creation of new optical frequencies, or new "colors". White light can be decomposed into different colors, but once separated, these colors usually remain invariable, e.g., blue light cannot change into red light. Nonlinear semiconductor materials such as GaP can be used to generate new "colors" in the far-infrared region, also referred to as terahertz (THz) radiation. Although GaP has been extensively used for over 60 years in photonic devices, no one to date had investigated techniques to dry-etch this material over a large-scale area to achieve sub-micron feature size. These are key requirements to implement any scalable applications based on a single-crystal photonic bandgap or metasurface. Mohammad developed, demonstrated and published the nanofabrication recipe to fabricate these structures. He demonstrated the quality of the nanofabricated materials with various characterization tools, including a THz system, which revealed enhanced performance after fabricating a phase grating at the surface of the GaP crystal. This work was conducted in collaboration with Prof. Angela Gamouras (National Research Council) and supported by the uOttawa-NRC Joint Centre for Extreme Photonics.
Thanks to skills gained in Prof. Ménard’s group, Mohammad moved on to a position as a ‘New Product Introduction-Optics Specialist’ at Agilent Technologies in Melbourne, Australia. He provides technical support and engineering expertise for the effective execution of new products in Agilent’s spectroscopy division. Moreover, he supports production by reducing manufacturing costs and improving service quality while ensuring on-time delivery of optical components.
Mohammad’s most important lesson learned at uOttawa was to always think outside the box. He says, “In order to make changes, especially in a high-tech environment, novelty is the main element to consider.”
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