Cavity-enhanced field-resolved spectroscopy

Sulzer, Philipp; Hoegner, Maximilian; Raab, Ann-Kathrin; Fuerst, Lukas; Fill, Ernst; Gerz, Daniel; Hofer, Christina; Voronina, Liudmila und Pupeza, Ioachim (2022): Cavity-enhanced field-resolved spectroscopy. In: Nature Photonics, Bd. 16, Nr. 10: S. 692-697

Abstract

Femtosecond enhancement cavities(1) are key to applications including high-sensitivity linear(2-4) and nonlinear(5,6) gas spectroscopy, as well as efficient nonlinear optical frequency conversion(7-10). Yet, to date, the broadest simultaneously enhanced bandwidths amount to<20% of the central optical frequency (8,9,11-15). Here, we present an ultrabroadband femtosecond enhancement cavity comprising gold-coated mirrors and a wedged-diamond-plate input coupler, with an average finesse of 55 for optical frequencies below 40 THz and exceeding 40 in the 120-300 THz range. Resonant enhancement of a 50-MHz-repetition-rate offset-free frequency comb spanning 22-40 THz results in a waveform-stable ultrashort circulating pulse with a spectrum supporting a Fourier limit of 1.6 cycles, enabling time-domain electric-field-resolved spectroscopy of molecular samples with temporally separated excitation and molecular response(16). The contrast between the two is improved by taking advantage of destructive interference at the input coupler. At an effective interaction length with a gas of up to 81 m, this concept promises parts-per-trillion-level ultrabroadband electric-field-resolved linear and nonlinear spectroscopy of impulsively excited molecular vibrations.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 1749-4885
• Sprache: Englisch