(Ended Nov. 2015)

What is the TERACOMB project?

TERACOMB is an ambitious project focused on pursuing the technology of quantum cascade lasers (QCL) to generate a frequency comb (FC) in the terahertz frequency region.

To achieve the project goals, the main players in the QCL and FC technology have been brought on board. They are represented by senior scientists in their mid-career stage guaranteeing a long lasting dissemination/exploitation of the project achievements.

The expertise of the TERACOMB project partners covers the physics and technology of quantum cascade lasers, the growth of advanced semiconductor heterostructures, terahertz time-domain and time-resolved spectroscopy, microwave techniques, fibre laser technology, precise time and frequency measurement techniques, and the frequency comb technology. All that knowledge is exploited towards success of the TERACOMB project – the demonstration of a reliable terahertz frequency comb.

Last, but not least, the TERACOMB project could be brought to life thanks to the financial support of the European taxpayers via the European Commission.

The project

Despite significant research efforts during the past 10 years, the terahertz (THz) spectral range remains vastly underexploited, owing essentially to the insufficient signal-to-noise ratio (SNR) achievable with present technology.

The project’s aim is to address this problem by building a new technological platform enabling the generation of high power and broad bandwidth THz frequency combs (FCs) with a high frequency stability. The demonstration of FCs in the visible and near-IR spectral ranges has been among the main breakthroughs in the field of optics in the past decade. FCs are commonly generated by mode-locked lasers. In the frequency domain they consist of a broad spectrum of narrow lines, separated by a constant frequency interval, corresponding in the time domain to the repetition rate of the emitted pulse train. The time duration of the emitted pulses is roughly given by the inverse of the spectral bandwidth. Due to the lack of mode-locked lasers, FCs in the THz range are nowadays generated by inherently inefficient non-linear conversion techniques. This is the main cause for the low SNR of present THz systems.

The THz FCs envisioned in this project will be based on THz quantum cascade lasers (QCLs), a novel, compact and powerful THz semiconductor laser source. THz FCs will be generated by mode-locked THz QCLs, and/or by using THz QCLs as semiconductor amplifiers. This will allow the production of FCs with average powers in excess of 10mW, with a spectral bandwidth > 1THz, and a corresponding pulse duration < 1ps. Such high power THz FCs will be combined with highly sensitive coherent detection techniques based on compact fs-fiber lasers that will be developed ad hoc in this project. The ultimate goal is the realization of an enabling THz technology, which may be adapted for a wide variety of applications in fields such as physics, chemistry, biology and medicine.