Laser-Frequency Stabilization Based on Steady-State Spectral-Hole Burning in Eu3+: Y2SiO5

摘要

We present and analyze a method of laser-frequency stabilization via steady-state patterns of spectral holes in Eu3+:Y2SiO5. Three regions of spectral holes are created, spaced in frequency by the ground-state hyperfine splittings of Eu-151(3+). The absorption pattern is shown not to degrade after days of laser-frequency stabilization. An optical frequency comparison of a laser locked to such a steady-state spectral-hole pattern with an independent cavity-stabilized laser and a Yb optical lattice clock demonstrates a spectral-hole fractional frequency instability of 1.0 x 10(-15)tau(-1/2) that averages to 8.5(-1.8)(-4.8) x 10(-17) at tau = 73 s. Residual amplitude modulation at the frequency of the rf drive applied to the fiber-coupled electro-optic modulator is reduced to less than 1 x 10(-6) fractional amplitudemodulation at tau > 1 s by an active servo. The contribution of residual amplitude modulation to the laser-frequency instability is further reduced by digital division of the transmission and incident photodetector signals to less than 1 x 10(-16) at tau > 1 s.