CHIC - On CHip terahertz frequency Combs
P.I. Dr. Giacomo Scalari
The terahertz (THz) portion of the electromagnetic spectrum is at the junction between optics and electronics. As the fundamental vibration modes of many molecules lie in this spectral range, THz is a gate to sensing applications in fields as varied as medical, environmental and process control. Material inspection and non-invasive imaging for safety and medical applications greatly benefit from the non-ionizing, high resolution features of T-rays. The next major step for short-range high data rate wireless communication is the extension to higher frequencies entering the THz range.
Optical frequency combs have dominated the scene of laser physics in the last 10 years revolutionizing many fields of optics from metrology to high precision spectroscopy. Optical frequency combs act as rulers in the frequency domain and are characterized by their perfectly equally spaced and coherent modes. An extremely appealing application of optical frequency combs is the so-called dual-comb spectroscopy where multi-heterodyne detection is performed allowing broadband Fourier transform spectroscopy with high resolution, high sensitivity and no moving parts. Nowadays the THz range is still lacking bandwidth coverage and high power from frequency comb sources.
The objective of this proposal is to create on-chip, self-referenced frequency combs operating in the spectral region from 1.5-5-5 THz and room temperature on-chip dual band Mid-IR and THz combs.
Two main approaches will be followed during CHIC: direct generation with THz QCL and non-linear generation from room-temperature mid-IR QCLs. Such devices will be groundbreaking since they will enable on-chip, self-stabilized dual comb, spectrometers and they will pave the way to high-rate local data transmission providing a dense array of communication channels with ultra-high stability. The key innovative points are the on-chip, integrated nature of the devices, the self-referencing capability, the wavelength agility and the absence of an external detector.