High density THz frequency comb produced by coherent synchrotron radiation

Abstract

Frequency combs (FC) have radically changed the landscape of frequency metrology and high-resolution spectroscopy investigations extending tremendously the achievable resolution while increasing signal to noise ratio. Initially developed in the visible and near-IR spectral regions, the use of FC has been expanded to mid-IR, extreme ultra-violet and X-ray. Significant effort is presently dedicated to the generation of FC at THz frequencies. One solution based on converting a stabilized optical frequency comb using a photoconductive terahertz emitter, remains hampered by the low available THz power. Another approach is based on active mode locked THz quantum-cascade-lasers providing intense FC over a relatively limited spectral extension. Alternatively, here we show that dense powerful THz FC is generated over one decade of frequency by coherent synchrotron radiation (CSR). In this mode, the entire ring behaves in a similar fashion to a THz resonator wherein electron bunches emit powerful THz pulses quasi-synchronously. This FC presents unprecedented spectral characteristics and opens new perspectives for metrology investigations.

References in corpus (1)

• Broadband high-resolution x-ray frequency combs

Cited by in corpus (7)

• Frequency comb spectroscopy
• On-chip, self-detected THz dual-comb spectrometer
• Direct observation of spatio-temporal dynamics of short electron bunches in storage rings
• High sensitivity photonic time-stretch electro-optic sampling of terahertz pulses
• Coherent Terahertz synchrotron radiation mastered by controlling the irregular dynamics of relativistic electron bunches
• The sign of the polarizability anisotropy of polar molecules is obtained faithfully from terahertz Kerr effect
• Coherent frequency combs from electrons colliding with a laser pulse