Carrier-envelope offset frequency noise analysis in Ti:sapphire frequency combs

Abstract

We experimentally study two Ti:sapphire optical frequency comb femtosecond regimes, respectively, with a linear and a nonlinear dependence of the carrier-envelope offset frequency (f CEO ) on pump intensity. For both regimes, we study the effect of single-and multimode pump lasers on the f CEO phase noise. We demonstrate that the femtosecond regime is playing a more important role on the f CEO phase noise and stability than the pump laser type.

Towards DCS in the UV Spectral Range for Remote Sensing of Atmospheric Trace Gases

“…The phase noise RMS σ φ , squared, is obtained by integration of S ν n from the inverse of the observation time to an upper limit frequency of 50 MHz. The values reported by Sutyrin et al [55] are used and we verified that the contribution of the noise at Fourier frequencies higher than 1 MHz to the overall noise is negligible. The fast phase noise RMS corresponds to an observation time of 100 ms.…”

“…We decided to use an upper limit for the RIN, assumed constant. RIN values between −135 dBc/Hz, and −140 dBc/Hz have been reported in TiSa, from studies comparing different pump lasers [46,55,58]. Taking the highest of these RIN values, we estimate a RIN of −129 dB/Hz for SHG and −125 dB/Hz for THG.…”

“…The lowest optical phase noise of a TiSa frequency comb tooth has been achieved by phase-locking a comb tooth to an etalon optical source at 698 nm [55] or 657 nm [56]. From the work of Quraishi et al [56], we estimated the relative accumulated optical phase noise of OFC to be lower than 0.5 rad in the Fourier frequency range .…”

“…Coherence is therefore maintained over a single interferogram after SHG from the initial OFC. Sutyrin et al [55] reported an accumulated phase noise of 0.11 rad from 10 kHz to 100 kHz Fourier frequencies for the reference tooth. The frequency noise at another comb tooth can be estimated using Equation (A1).…”

Carrier-envelope offset frequency stabilization of a 100 fs-scale Ti:sapphire mode-locked laser for quantum frequency comb generation

“…The intensity fluctuation of the pump laser is the main amplitude noise source of the Ti:sapphire oscillator, which in turn causes the carrier-envelope phase variations due to the amplitude-to-phase coupling via the nonlinear Kerr effect in KLM [21,22]. Based on this mechanism, active modulation of the amplitude of the pump laser is treated as an effective means to apply feedback to the oscillator in the CEO frequency control loop, while the intrinsic intensity noise of the pump laser will limit the stabilization due to the same mechanism.…”