Caltech Mixed-Signal, RF & Microwave Seminar

Our ability to synthesize, control and detect electromagnetic fields across
the spectrum in integrated chip-scale technologies have followed a quasi-Moore law
allowing us access over a spectrum orders of magnitude larger than we have had at
any point in time. In future, as sensing and communication converges across this
enormous EM spectrum potentially shared among trillions of devices, enabling a
seamless co-existence will require these participating devices to be able to sense
available resources, make intelligent decisions and reconfigure accordingly.
At a high level of abstraction, such a universal wireless system is one which can
receive, sense and transmit efficiently arbitrary EM spectrum (RF-THz) and EM field
profile, and extract information efficiently. Enabling such an architecture requires revisiting
traditional approaches towards signal generation, reception, and information
extraction right from the EM interface to the signal processing layer. In the first part
of the talk, we will show examples of an approach that exploits sub-wavelength
sensing and synthesis of radiated EM fields and strongly interacting transceiver
elements to directly extract information (spectral) and impart efficient
reconfigurability in transmission and reception varying across 30-350 GHz. As we
will discuss, this contrarian approach, of utilizing multiple interacting EM
components and system elements in a co-design approach, can dissociate many of
the classical design trade-offs, and lead to new capabilities and systems for
sensing, imagining and communication.
Extending into higher frequencies, we will discuss how metal-light interactions with
sub-wavelength lithographic features in interconnect layers embedded in modernday
silicon processes can be exploited to enable complex multi-functional nanooptical
components in the visible range. Particularly, we will show the first fully
integrated fluorescence-based multiplexed bio-molecular sensor with integrated
nanoplasmonic filters in CMOS, that requires no post processing or external optical
passives, and demonstrates surface-sensitivities reaching down to sub-zeptomole
passives, and demonstrates surface-sensitivities reaching down to sub-zeptomole
level. Manipulating optical fields with integrated metal-optic structures are also
demonstrated in the first fully integrated optical spectrometer and optical PUF in
silicon between 500-900 nm. Ultra-miniaturization of massively complex optical
systems-on-chip in the visible range can have a transformative impact in sensing
and imaging technologies for a wide range of new applications.