Stuttgart 2012 – wissenschaftliches Programm
Q 16.2: Vortrag
Montag, 12. März 2012, 16:45–17:00, V7.03
A sub-40 mHz linewidth laser based on a single-crystal silicon optical cavity — •Christian Hagemann1, Thomas Kessler1, Thomas Legero1, Uwe Sterr1, Fritz Riehle1, Michael J. Martin2, Lisheng Chen2, and Jun Ye2 — 1Physikalisch-Technische Bundesanstalt (PTB) and Centre for Quantum Engineering and Space-Time Research (QUEST), Bundesallee 100, 38116 Braunschweig, Germany — 2JILA, NIST and University of Colorado, 440 UCB, Boulder, CO 80309-0440, USA
State-of-the-art ultra-stable lasers achieve fractional frequency stabilities of a few times 10−16, limited by the thermal noise of the high-finesse optical cavities used as reference.
We present a novel optical cavity machined from single-crystal silicon with the potential to push this limitation by one order of magnitude. Various key advantages of silicon as resonator material compared to conventionally used ultra-low expansion (ULE) glass will be discussed. To minimize the impact of thermal instabilities we operate the cavity at its minimum of thermal expansion at a temperature of 124 K in a low-vibration cryostat with nitrogen gas as coolant. In a three-cornered hat frequency comparison with two ULE glass reference cavities we show that the laser frequency-stabilized to the silicon cavity reaches a world-record instability of 10−16 and a linewidth of below 40 mHz, the lowest linewidth observed for any laser systems.
We give an outlook on possible applications enabled by dissemination and frequency transfer of this ultra-stable laser light via fiber networks and optical frequency combs.