Photonics, the science of generating and/or processing light waves on a micrometer-scale, is enabling evermore applications, including LED-lightning, fiber-to-the-home internet, solar panels, displays and image sensors. Recent progress in nano-fabrication now also allow to produce large-scale photonic circuits on wafer-scale with CMOS-compatible processes, providing cost-effective high-quality optical systems. Imec is playing a crucial role in the development of wafer-scale photonics, and already developed state-of-the-art photonics platforms for high-speed optical communication, ranging, treatment, projection, industrial and biomedical sensing in the near infrared and visible ranges (Fig.1).
Optical beam forming, implementing phased arrays of nano-photonic antennas, is seen as a great enabling technology for applications currently being mapped on integrated photonic platforms, e.g., solid-state scanning LiDAR, integrated lens free imaging and, in particular, optical resolution photo-acoustic microscopy (OR-PAM) through turbulent or scattering media. OR-PAM is a powerful imaging technique delivering exquisite resolution with high sensitivity and selectivity in applications as groundbreaking as through-skull real time functional brain imaging. However, OR-PAM relies on the precise time-multiplexed delivery of pulsed optical energy in focus points scanning the scene. The selective absorption of the optical energy translates in an acoustic wave detected using ultrasound microphones. As optical waves are typically scattered by biological tissues, OR-PAM is in practical applications limited to shallow depth imaging. This situation can be drastically impacted by the development of advanced beam formers able to project and control the complete light field in the illuminated scene, thus to compensate for parasitic scattering.
This PhD aims at revolutionizing optical beam forming, and OR-PAM as a consequence, by developing the “ultimate beamformer in the visible”, a novel type of agile integrated holographic projection chip relying on tunable diffractive optical elements arranged in large 2D array with vastly sub-wavelength pitch (~100nm). For this purpose, the PhD candidate will be embedded at the interface between imec teams at the forefront of memory, photonics, algorithms, high performance computers and microsystems for life science developments. The candidate will perform literature study, model options for sub-wavelength switchable scatterers, derive their benefits and drawbacks taking integration approaches into account. The candidate will contribute to the development of proofs of concept. Together with the life science experts and fabrication teams, the candidate will participate to the design, simulation, development, manufacturing and characterization of OR-PAM prototypes implementing the novel beam former chip.
Required background: physics, electrical engineering
Type of work: 20% literature study, 30% modelling, 20% processing, 30% characterization
Supervisors: Pol Van Dorpe, Liesbet Lagae
Daily advisor: Xavier Rottenberg
The reference code for this PhD position is SE1712-28. Mention this reference code on your application form.