Microphotonics-based frequency combs for habitable exoplanet detection

Projektbeschreibung

Mit Mikroresonator-Astrokämmen nach bewohnbaren Exoplaneten suchen

Das EU-finanzierte Projekt STARCHIP entwickelt einen neuen Typ des Laserfrequenzkamms, der die Suche der Wissenschaft nach bewohnbaren Exoplaneten optimieren könnte. Laserfrequenzkämme erzeugen Spektrallinien des Lichts mit gleichmäßig verteilten Frequenzen, mit deren Hilfe winzige Wellenlängenverschiebungen in den optischen Spektren der Wirtssterne von Exoplaneten zu beobachten sind. An diese Frequenzkammspektren mit auflösbaren Linien zu gelangen, ist jedoch äußerst schwierig. Die neuartige Klasse der STARCHIP-Astrokämme auf der Basis von Photonenchip-Mikroresonatoren wird breitbandige Spektren auflösbarer Linien liefern, die potenziell vom sichtbaren bis in den mittleren Infrarot-Wellenlängenbereich reichen. Damit werden wichtige Probleme bei der Erzeugung von Astrokämmen lösbar.

Ziel

Without doubt, one of the most intriguing questions in modern astronomy is whether habitable planets, potentially supporting life, exist outside our solar system. In the upcoming era of large aperture astronomical telescopes and highly stable spectrometers, answering these questions is for the first time a tangible possibility. Successfully finding answers to these questions will, however, critically rely on non-incremental advances in astronomical instrumentation. The objective of the proposed research is, developing and demonstrating novel photonic-chip laser frequency combs to support the revolutionary advances in astronomical precision spectroscopy required to enable detection and characterization of habitable Earth-like planets.
Habitable exo-planets can be discovered by observing minute wavelength-shifts in the optical spectra of their host stars. These wavelength-shifts are so small that exquisitely accurate and precise wavelength-calibration of astronomical spectrometers is required. It has been recognized that laser frequency combs (LFCs), broadband spectra of laser-lines with absolutely-known optical frequencies, can provide the required level of precision, provided the LFCâ€™s lines can be resolved by the spectrometer. Generating such frequency comb spectra (â€œastrocombsâ€?) with resolvable lines remains, however, exceedingly challenging.
Here, we will develop and demonstrate a novel class of photonic-chip microresonator-based astrocombs that can naturally provide broadband spectra of resolvable lines, potentially from visible to mid-infrared wavelengths, thereby overcoming key challenges in astrocomb generation. In order to achieve this goal we will pursue radically different microresonator designs and new nonlinear optical regimes in order to overcome long-standing limitation in microresonator physics. The developed astrocombs will not only be pivotal to astronomy but indeed can directly and profoundly impact the way we transfer data, monitor our environm